1This is diffutils.info, produced by makeinfo version 6.5 from 2diffutils.texi. 3 4This manual is for GNU Diffutils (version 3.7, 7 January 2018), and 5documents the GNU 'diff', 'diff3', 'sdiff', and 'cmp' commands for 6showing the differences between files and the GNU 'patch' command for 7using their output to update files. 8 9 Copyright (C) 1992-1994, 1998, 2001-2002, 2004, 2006, 2009-2018 Free 10Software Foundation, Inc. 11 12 Permission is granted to copy, distribute and/or modify this 13 document under the terms of the GNU Free Documentation License, 14 Version 1.3 or any later version published by the Free Software 15 Foundation; with no Invariant Sections, no Front-Cover Texts, and 16 no Back-Cover Texts. A copy of the license is included in the 17 section entitled "GNU Free Documentation License." 18INFO-DIR-SECTION Individual utilities 19START-INFO-DIR-ENTRY 20* cmp: (diffutils)Invoking cmp. Compare 2 files byte by byte. 21* diff: (diffutils)Invoking diff. Compare 2 files line by line. 22* diff3: (diffutils)Invoking diff3. Compare 3 files line by line. 23* patch: (diffutils)Invoking patch. Apply a patch to a file. 24* sdiff: (diffutils)Invoking sdiff. Merge 2 files side-by-side. 25END-INFO-DIR-ENTRY 26 27INFO-DIR-SECTION Text creation and manipulation 28START-INFO-DIR-ENTRY 29* Diffutils: (diffutils). Comparing and merging files. 30END-INFO-DIR-ENTRY 31 32 33File: diffutils.info, Node: Top, Next: Overview, Up: (dir) 34 35Comparing and Merging Files 36*************************** 37 38This manual is for GNU Diffutils (version 3.7, 7 January 2018), and 39documents the GNU 'diff', 'diff3', 'sdiff', and 'cmp' commands for 40showing the differences between files and the GNU 'patch' command for 41using their output to update files. 42 43 Copyright (C) 1992-1994, 1998, 2001-2002, 2004, 2006, 2009-2018 Free 44Software Foundation, Inc. 45 46 Permission is granted to copy, distribute and/or modify this 47 document under the terms of the GNU Free Documentation License, 48 Version 1.3 or any later version published by the Free Software 49 Foundation; with no Invariant Sections, no Front-Cover Texts, and 50 no Back-Cover Texts. A copy of the license is included in the 51 section entitled "GNU Free Documentation License." 52 53* Menu: 54 55* Overview:: Preliminary information. 56* Comparison:: What file comparison means. 57 58* Output Formats:: Formats for two-way difference reports. 59* Incomplete Lines:: Lines that lack trailing newlines. 60* Comparing Directories:: Comparing files and directories. 61* Adjusting Output:: Making 'diff' output prettier. 62* diff Performance:: Making 'diff' smarter or faster. 63 64* Comparing Three Files:: Formats for three-way difference reports. 65* diff3 Merging:: Merging from a common ancestor. 66 67* Interactive Merging:: Interactive merging with 'sdiff'. 68 69* Merging with patch:: Using 'patch' to change old files into new ones. 70* Making Patches:: Tips for making and using patch distributions. 71 72* Invoking cmp:: Compare two files byte by byte. 73* Invoking diff:: Compare two files line by line. 74* Invoking diff3:: Compare three files line by line. 75* Invoking patch:: Apply a diff file to an original. 76* Invoking sdiff:: Side-by-side merge of file differences. 77 78* Standards conformance:: Conformance to the POSIX standard. 79* Projects:: If you've found a bug or other shortcoming. 80 81* Copying This Manual:: How to make copies of this manual. 82* Translations:: Available translations of this manual. 83* Index:: Index. 84 85 86File: diffutils.info, Node: Overview, Next: Comparison, Prev: Top, Up: Top 87 88Overview 89******** 90 91Computer users often find occasion to ask how two files differ. Perhaps 92one file is a newer version of the other file. Or maybe the two files 93started out as identical copies but were changed by different people. 94 95 You can use the 'diff' command to show differences between two files, 96or each corresponding file in two directories. 'diff' outputs 97differences between files line by line in any of several formats, 98selectable by command line options. This set of differences is often 99called a "diff" or "patch". For files that are identical, 'diff' 100normally produces no output; for binary (non-text) files, 'diff' 101normally reports only that they are different. 102 103 You can use the 'cmp' command to show the byte and line numbers where 104two files differ. 'cmp' can also show all the bytes that differ between 105the two files, side by side. A way to compare two files character by 106character is the Emacs command 'M-x compare-windows'. *Note Other 107Window: (emacs)Other Window, for more information on that command. 108 109 You can use the 'diff3' command to show differences among three 110files. When two people have made independent changes to a common 111original, 'diff3' can report the differences between the original and 112the two changed versions, and can produce a merged file that contains 113both persons' changes together with warnings about conflicts. 114 115 You can use the 'sdiff' command to merge two files interactively. 116 117 You can use the set of differences produced by 'diff' to distribute 118updates to text files (such as program source code) to other people. 119This method is especially useful when the differences are small compared 120to the complete files. Given 'diff' output, you can use the 'patch' 121program to update, or "patch", a copy of the file. If you think of 122'diff' as subtracting one file from another to produce their difference, 123you can think of 'patch' as adding the difference to one file to 124reproduce the other. 125 126 This manual first concentrates on making diffs, and later shows how 127to use diffs to update files. 128 129 GNU 'diff' was written by Paul Eggert, Mike Haertel, David Hayes, 130Richard Stallman, and Len Tower. Wayne Davison designed and implemented 131the unified output format. The basic algorithm is described by Eugene 132W. Myers in "An O(ND) Difference Algorithm and its Variations", 133'Algorithmica' Vol. 1, 1986, pp. 251-266, 134<http://dx.doi.org/10.1007/BF01840446>; and in "A File Comparison 135Program", Webb Miller and Eugene W. Myers, 'Software--Practice and 136Experience' Vol. 15, 1985, pp. 1025-1040, 137<http://dx.doi.org/10.1002/spe.4380151102>. The algorithm was 138independently discovered as described by Esko Ukkonen in "Algorithms for 139Approximate String Matching", 'Information and Control' Vol. 64, 1985, 140pp. 100-118, <http://dx.doi.org/10.1016/S0019-9958(85)80046-2>. Unless 141the '--minimal' option is used, 'diff' uses a heuristic by Paul Eggert 142that limits the cost to O(N^1.5 log N) at the price of producing 143suboptimal output for large inputs with many differences. Related 144algorithms are surveyed by Alfred V. Aho in section 6.3 of "Algorithms 145for Finding Patterns in Strings", 'Handbook of Theoretical Computer 146Science' (Jan Van Leeuwen, ed.), Vol. A, 'Algorithms and Complexity', 147Elsevier/MIT Press, 1990, pp. 255-300. 148 149 GNU 'diff3' was written by Randy Smith. GNU 'sdiff' was written by 150Thomas Lord. GNU 'cmp' was written by Torbjo"rn Granlund and David 151MacKenzie. 152 153 GNU 'patch' was written mainly by Larry Wall and Paul Eggert; several 154GNU enhancements were contributed by Wayne Davison and David MacKenzie. 155Parts of this manual are adapted from a manual page written by Larry 156Wall, with his permission. 157 158 159File: diffutils.info, Node: Comparison, Next: Output Formats, Prev: Overview, Up: Top 160 1611 What Comparison Means 162*********************** 163 164There are several ways to think about the differences between two files. 165One way to think of the differences is as a series of lines that were 166deleted from, inserted in, or changed in one file to produce the other 167file. 'diff' compares two files line by line, finds groups of lines 168that differ, and reports each group of differing lines. It can report 169the differing lines in several formats, which have different purposes. 170 171 GNU 'diff' can show whether files are different without detailing the 172differences. It also provides ways to suppress certain kinds of 173differences that are not important to you. Most commonly, such 174differences are changes in the amount of white space between words or 175lines. 'diff' also provides ways to suppress differences in alphabetic 176case or in lines that match a regular expression that you provide. 177These options can accumulate; for example, you can ignore changes in 178both white space and alphabetic case. 179 180 Another way to think of the differences between two files is as a 181sequence of pairs of bytes that can be either identical or different. 182'cmp' reports the differences between two files byte by byte, instead of 183line by line. As a result, it is often more useful than 'diff' for 184comparing binary files. For text files, 'cmp' is useful mainly when you 185want to know only whether two files are identical, or whether one file 186is a prefix of the other. 187 188 To illustrate the effect that considering changes byte by byte can 189have compared with considering them line by line, think of what happens 190if a single newline character is added to the beginning of a file. If 191that file is then compared with an otherwise identical file that lacks 192the newline at the beginning, 'diff' will report that a blank line has 193been added to the file, while 'cmp' will report that almost every byte 194of the two files differs. 195 196 'diff3' normally compares three input files line by line, finds 197groups of lines that differ, and reports each group of differing lines. 198Its output is designed to make it easy to inspect two different sets of 199changes to the same file. 200 201 These commands compare input files without necessarily reading them. 202For example, if 'diff' is asked simply to report whether two files 203differ, and it discovers that the files have different sizes, it need 204not read them to do its job. 205 206* Menu: 207 208* Hunks:: Groups of differing lines. 209* White Space:: Suppressing differences in white space. 210* Blank Lines:: Suppressing differences whose lines are all blank. 211* Specified Lines:: Suppressing differences whose lines all match a pattern. 212* Case Folding:: Suppressing differences in alphabetic case. 213* Brief:: Summarizing which files are different. 214* Binary:: Comparing binary files or forcing text comparisons. 215 216 217File: diffutils.info, Node: Hunks, Next: White Space, Up: Comparison 218 2191.1 Hunks 220========= 221 222When comparing two files, 'diff' finds sequences of lines common to both 223files, interspersed with groups of differing lines called "hunks". 224Comparing two identical files yields one sequence of common lines and no 225hunks, because no lines differ. Comparing two entirely different files 226yields no common lines and one large hunk that contains all lines of 227both files. In general, there are many ways to match up lines between 228two given files. 'diff' tries to minimize the total hunk size by 229finding large sequences of common lines interspersed with small hunks of 230differing lines. 231 232 For example, suppose the file 'F' contains the three lines 'a', 'b', 233'c', and the file 'G' contains the same three lines in reverse order 234'c', 'b', 'a'. If 'diff' finds the line 'c' as common, then the command 235'diff F G' produces this output: 236 237 1,2d0 238 < a 239 < b 240 3a2,3 241 > b 242 > a 243 244But if 'diff' notices the common line 'b' instead, it produces this 245output: 246 247 1c1 248 < a 249 --- 250 > c 251 3c3 252 < c 253 --- 254 > a 255 256It is also possible to find 'a' as the common line. 'diff' does not 257always find an optimal matching between the files; it takes shortcuts to 258run faster. But its output is usually close to the shortest possible. 259You can adjust this tradeoff with the '--minimal' ('-d') option (*note 260diff Performance::). 261 262 263File: diffutils.info, Node: White Space, Next: Blank Lines, Prev: Hunks, Up: Comparison 264 2651.2 Suppressing Differences in Blank and Tab Spacing 266==================================================== 267 268The '--ignore-tab-expansion' ('-E') option ignores the distinction 269between tabs and spaces on input. A tab is considered to be equivalent 270to the number of spaces to the next tab stop (*note Tabs::). 271 272 The '--ignore-trailing-space' ('-Z') option ignores white space at 273line end. 274 275 The '--ignore-space-change' ('-b') option is stronger than '-E' and 276'-Z' combined. It ignores white space at line end, and considers all 277other sequences of one or more white space characters within a line to 278be equivalent. With this option, 'diff' considers the following two 279lines to be equivalent, where '$' denotes the line end: 280 281 Here lyeth muche rychnesse in lytell space. -- John Heywood$ 282 Here lyeth muche rychnesse in lytell space. -- John Heywood $ 283 284 The '--ignore-all-space' ('-w') option is stronger still. It ignores 285differences even if one line has white space where the other line has 286none. "White space" characters include tab, vertical tab, form feed, 287carriage return, and space; some locales may define additional 288characters to be white space. With this option, 'diff' considers the 289following two lines to be equivalent, where '$' denotes the line end and 290'^M' denotes a carriage return: 291 292 Here lyeth muche rychnesse in lytell space.-- John Heywood$ 293 He relyeth much erychnes seinly tells pace. --John Heywood ^M$ 294 295 For many other programs newline is also a white space character, but 296'diff' is a line-oriented program and a newline character always ends a 297line. Hence the '-w' or '--ignore-all-space' option does not ignore 298newline-related changes; it ignores only other white space changes. 299 300 301File: diffutils.info, Node: Blank Lines, Next: Specified Lines, Prev: White Space, Up: Comparison 302 3031.3 Suppressing Differences Whose Lines Are All Blank 304===================================================== 305 306The '--ignore-blank-lines' ('-B') option ignores changes that consist 307entirely of blank lines. With this option, for example, a file 308containing 309 1. A point is that which has no part. 310 311 2. A line is breadthless length. 312 -- Euclid, The Elements, I 313is considered identical to a file containing 314 1. A point is that which has no part. 315 2. A line is breadthless length. 316 317 318 -- Euclid, The Elements, I 319 320 Normally this option affects only lines that are completely empty, 321but if you also specify an option that ignores trailing spaces, lines 322are also affected if they look empty but contain white space. In other 323words, '-B' is equivalent to '-I '^$'' by default, but it is equivalent 324to '-I '^[[:space:]]*$'' if '-b', '-w' or '-Z' is also specified. 325 326 327File: diffutils.info, Node: Specified Lines, Next: Case Folding, Prev: Blank Lines, Up: Comparison 328 3291.4 Suppressing Differences Whose Lines All Match a Regular Expression 330====================================================================== 331 332To ignore insertions and deletions of lines that match a 'grep'-style 333regular expression, use the '--ignore-matching-lines=REGEXP' ('-I 334REGEXP') option. You should escape regular expressions that contain 335shell metacharacters to prevent the shell from expanding them. For 336example, 'diff -I '^[[:digit:]]'' ignores all changes to lines beginning 337with a digit. 338 339 However, '-I' only ignores the insertion or deletion of lines that 340contain the regular expression if every changed line in the hunk--every 341insertion and every deletion--matches the regular expression. In other 342words, for each nonignorable change, 'diff' prints the complete set of 343changes in its vicinity, including the ignorable ones. 344 345 You can specify more than one regular expression for lines to ignore 346by using more than one '-I' option. 'diff' tries to match each line 347against each regular expression. 348 349 350File: diffutils.info, Node: Case Folding, Next: Brief, Prev: Specified Lines, Up: Comparison 351 3521.5 Suppressing Case Differences 353================================ 354 355GNU 'diff' can treat lower case letters as equivalent to their upper 356case counterparts, so that, for example, it considers 'Funky Stuff', 357'funky STUFF', and 'fUNKy stuFf' to all be the same. To request this, 358use the '-i' or '--ignore-case' option. 359 360 361File: diffutils.info, Node: Brief, Next: Binary, Prev: Case Folding, Up: Comparison 362 3631.6 Summarizing Which Files Differ 364================================== 365 366When you only want to find out whether files are different, and you 367don't care what the differences are, you can use the summary output 368format. In this format, instead of showing the differences between the 369files, 'diff' simply reports whether files differ. The '--brief' ('-q') 370option selects this output format. 371 372 This format is especially useful when comparing the contents of two 373directories. It is also much faster than doing the normal line by line 374comparisons, because 'diff' can stop analyzing the files as soon as it 375knows that there are any differences. 376 377 You can also get a brief indication of whether two files differ by 378using 'cmp'. For files that are identical, 'cmp' produces no output. 379When the files differ, by default, 'cmp' outputs the byte and line 380number where the first difference occurs, or reports that one file is a 381prefix of the other. You can use the '-s', '--quiet', or '--silent' 382option to suppress that information, so that 'cmp' produces no output 383and reports whether the files differ using only its exit status (*note 384Invoking cmp::). 385 386 Unlike 'diff', 'cmp' cannot compare directories; it can only compare 387two files. 388 389 390File: diffutils.info, Node: Binary, Prev: Brief, Up: Comparison 391 3921.7 Binary Files and Forcing Text Comparisons 393============================================= 394 395If 'diff' thinks that either of the two files it is comparing is binary 396(a non-text file), it normally treats that pair of files much as if the 397summary output format had been selected (*note Brief::), and reports 398only that the binary files are different. This is because line by line 399comparisons are usually not meaningful for binary files. This does not 400count as trouble, even though the resulting output does not capture all 401the differences. 402 403 'diff' determines whether a file is text or binary by checking the 404first few bytes in the file; the exact number of bytes is system 405dependent, but it is typically several thousand. If every byte in that 406part of the file is non-null, 'diff' considers the file to be text; 407otherwise it considers the file to be binary. 408 409 Sometimes you might want to force 'diff' to consider files to be 410text. For example, you might be comparing text files that contain null 411characters; 'diff' would erroneously decide that those are non-text 412files. Or you might be comparing documents that are in a format used by 413a word processing system that uses null characters to indicate special 414formatting. You can force 'diff' to consider all files to be text 415files, and compare them line by line, by using the '--text' ('-a') 416option. If the files you compare using this option do not in fact 417contain text, they will probably contain few newline characters, and the 418'diff' output will consist of hunks showing differences between long 419lines of whatever characters the files contain. 420 421 You can also force 'diff' to report only whether files differ (but 422not how). Use the '--brief' ('-q') option for this. 423 424 In operating systems that distinguish between text and binary files, 425'diff' normally reads and writes all data as text. Use the '--binary' 426option to force 'diff' to read and write binary data instead. This 427option has no effect on a POSIX-compliant system like GNU or traditional 428Unix. However, many personal computer operating systems represent the 429end of a line with a carriage return followed by a newline. On such 430systems, 'diff' normally ignores these carriage returns on input and 431generates them at the end of each output line, but with the '--binary' 432option 'diff' treats each carriage return as just another input 433character, and does not generate a carriage return at the end of each 434output line. This can be useful when dealing with non-text files that 435are meant to be interchanged with POSIX-compliant systems. 436 437 The '--strip-trailing-cr' causes 'diff' to treat input lines that end 438in carriage return followed by newline as if they end in plain newline. 439This can be useful when comparing text that is imperfectly imported from 440many personal computer operating systems. This option affects how lines 441are read, which in turn affects how they are compared and output. 442 443 If you want to compare two files byte by byte, you can use the 'cmp' 444program with the '--verbose' ('-l') option to show the values of each 445differing byte in the two files. With GNU 'cmp', you can also use the 446'-b' or '--print-bytes' option to show the ASCII representation of those 447bytes. *Note Invoking cmp::, for more information. 448 449 If 'diff3' thinks that any of the files it is comparing is binary (a 450non-text file), it normally reports an error, because such comparisons 451are usually not useful. 'diff3' uses the same test as 'diff' to decide 452whether a file is binary. As with 'diff', if the input files contain a 453few non-text bytes but otherwise are like text files, you can force 454'diff3' to consider all files to be text files and compare them line by 455line by using the '-a' or '--text' option. 456 457 458File: diffutils.info, Node: Output Formats, Next: Incomplete Lines, Prev: Comparison, Up: Top 459 4602 'diff' Output Formats 461*********************** 462 463'diff' has several mutually exclusive options for output format. The 464following sections describe each format, illustrating how 'diff' reports 465the differences between two sample input files. 466 467* Menu: 468 469* Sample diff Input:: Sample 'diff' input files for examples. 470* Context:: Showing differences with the surrounding text. 471* Side by Side:: Showing differences in two columns. 472* Normal:: Showing differences without surrounding text. 473* Scripts:: Generating scripts for other programs. 474* If-then-else:: Merging files with if-then-else. 475 476 477File: diffutils.info, Node: Sample diff Input, Next: Context, Up: Output Formats 478 4792.1 Two Sample Input Files 480========================== 481 482Here are two sample files that we will use in numerous examples to 483illustrate the output of 'diff' and how various options can change it. 484 485 This is the file 'lao': 486 487 The Way that can be told of is not the eternal Way; 488 The name that can be named is not the eternal name. 489 The Nameless is the origin of Heaven and Earth; 490 The Named is the mother of all things. 491 Therefore let there always be non-being, 492 so we may see their subtlety, 493 And let there always be being, 494 so we may see their outcome. 495 The two are the same, 496 But after they are produced, 497 they have different names. 498 499 This is the file 'tzu': 500 501 The Nameless is the origin of Heaven and Earth; 502 The named is the mother of all things. 503 504 Therefore let there always be non-being, 505 so we may see their subtlety, 506 And let there always be being, 507 so we may see their outcome. 508 The two are the same, 509 But after they are produced, 510 they have different names. 511 They both may be called deep and profound. 512 Deeper and more profound, 513 The door of all subtleties! 514 515 In this example, the first hunk contains just the first two lines of 516'lao', the second hunk contains the fourth line of 'lao' opposing the 517second and third lines of 'tzu', and the last hunk contains just the 518last three lines of 'tzu'. 519 520 521File: diffutils.info, Node: Context, Next: Side by Side, Prev: Sample diff Input, Up: Output Formats 522 5232.2 Showing Differences in Their Context 524======================================== 525 526Usually, when you are looking at the differences between files, you will 527also want to see the parts of the files near the lines that differ, to 528help you understand exactly what has changed. These nearby parts of the 529files are called the "context". 530 531 GNU 'diff' provides two output formats that show context around the 532differing lines: "context format" and "unified format". It can 533optionally show in which function or section of the file the differing 534lines are found. 535 536 If you are distributing new versions of files to other people in the 537form of 'diff' output, you should use one of the output formats that 538show context so that they can apply the diffs even if they have made 539small changes of their own to the files. 'patch' can apply the diffs in 540this case by searching in the files for the lines of context around the 541differing lines; if those lines are actually a few lines away from where 542the diff says they are, 'patch' can adjust the line numbers accordingly 543and still apply the diff correctly. *Note Imperfect::, for more 544information on using 'patch' to apply imperfect diffs. 545 546* Menu: 547 548* Context Format:: An output format that shows surrounding lines. 549* Unified Format:: A more compact output format that shows context. 550* Sections:: Showing which sections of the files differences are in. 551* Alternate Names:: Showing alternate file names in context headers. 552 553 554File: diffutils.info, Node: Context Format, Next: Unified Format, Up: Context 555 5562.2.1 Context Format 557-------------------- 558 559The context output format shows several lines of context around the 560lines that differ. It is the standard format for distributing updates 561to source code. 562 563 To select this output format, use the '--context[=LINES]' ('-C 564LINES') or '-c' option. The argument LINES that some of these options 565take is the number of lines of context to show. If you do not specify 566LINES, it defaults to three. For proper operation, 'patch' typically 567needs at least two lines of context. 568 569* Menu: 570 571* Example Context:: Sample output in context format. 572* Less Context:: Another sample with less context. 573* Detailed Context:: A detailed description of the context output format. 574 575 576File: diffutils.info, Node: Example Context, Next: Less Context, Up: Context Format 577 5782.2.1.1 An Example of Context Format 579.................................... 580 581Here is the output of 'diff -c lao tzu' (*note Sample diff Input::, for 582the complete contents of the two files). Notice that up to three lines 583that are not different are shown around each line that is different; 584they are the context lines. Also notice that the first two hunks have 585run together, because their contents overlap. 586 587 *** lao 2002-02-21 23:30:39.942229878 -0800 588 --- tzu 2002-02-21 23:30:50.442260588 -0800 589 *************** 590 *** 1,7 **** 591 - The Way that can be told of is not the eternal Way; 592 - The name that can be named is not the eternal name. 593 The Nameless is the origin of Heaven and Earth; 594 ! The Named is the mother of all things. 595 Therefore let there always be non-being, 596 so we may see their subtlety, 597 And let there always be being, 598 --- 1,6 ---- 599 The Nameless is the origin of Heaven and Earth; 600 ! The named is the mother of all things. 601 ! 602 Therefore let there always be non-being, 603 so we may see their subtlety, 604 And let there always be being, 605 *************** 606 *** 9,11 **** 607 --- 8,13 ---- 608 The two are the same, 609 But after they are produced, 610 they have different names. 611 + They both may be called deep and profound. 612 + Deeper and more profound, 613 + The door of all subtleties! 614 615 616File: diffutils.info, Node: Less Context, Next: Detailed Context, Prev: Example Context, Up: Context Format 617 6182.2.1.2 An Example of Context Format with Less Context 619...................................................... 620 621Here is the output of 'diff -C 1 lao tzu' (*note Sample diff Input::, 622for the complete contents of the two files). Notice that at most one 623context line is reported here. 624 625 *** lao 2002-02-21 23:30:39.942229878 -0800 626 --- tzu 2002-02-21 23:30:50.442260588 -0800 627 *************** 628 *** 1,5 **** 629 - The Way that can be told of is not the eternal Way; 630 - The name that can be named is not the eternal name. 631 The Nameless is the origin of Heaven and Earth; 632 ! The Named is the mother of all things. 633 Therefore let there always be non-being, 634 --- 1,4 ---- 635 The Nameless is the origin of Heaven and Earth; 636 ! The named is the mother of all things. 637 ! 638 Therefore let there always be non-being, 639 *************** 640 *** 11 **** 641 --- 10,13 ---- 642 they have different names. 643 + They both may be called deep and profound. 644 + Deeper and more profound, 645 + The door of all subtleties! 646 647 648File: diffutils.info, Node: Detailed Context, Prev: Less Context, Up: Context Format 649 6502.2.1.3 Detailed Description of Context Format 651.............................................. 652 653The context output format starts with a two-line header, which looks 654like this: 655 656 *** FROM-FILE FROM-FILE-MODIFICATION-TIME 657 --- TO-FILE TO-FILE-MODIFICATION TIME 658 659The timestamp normally looks like '2002-02-21 23:30:39.942229878 -0800' 660to indicate the date, time with fractional seconds, and time zone in 661Internet RFC 2822 format (ftp://ftp.isi.edu/in-notes/rfc2822.txt). (The 662fractional seconds are omitted on hosts that do not support fractional 663timestamps.) However, a traditional timestamp like 'Thu Feb 21 23:30:39 6642002' is used if the 'LC_TIME' locale category is either 'C' or 'POSIX'. 665 666 You can change the header's content with the '--label=LABEL' option; 667see *note Alternate Names::. 668 669 Next come one or more hunks of differences; each hunk shows one area 670where the files differ. Context format hunks look like this: 671 672 *************** 673 *** FROM-FILE-LINE-NUMBERS **** 674 FROM-FILE-LINE 675 FROM-FILE-LINE... 676 --- TO-FILE-LINE-NUMBERS ---- 677 TO-FILE-LINE 678 TO-FILE-LINE... 679 680 If a hunk contains two or more lines, its line numbers look like 681'START,END'. Otherwise only its end line number appears. An empty hunk 682is considered to end at the line that precedes the hunk. 683 684 The lines of context around the lines that differ start with two 685space characters. The lines that differ between the two files start 686with one of the following indicator characters, followed by a space 687character: 688 689'!' 690 A line that is part of a group of one or more lines that changed 691 between the two files. There is a corresponding group of lines 692 marked with '!' in the part of this hunk for the other file. 693 694'+' 695 An "inserted" line in the second file that corresponds to nothing 696 in the first file. 697 698'-' 699 A "deleted" line in the first file that corresponds to nothing in 700 the second file. 701 702 If all of the changes in a hunk are insertions, the lines of 703FROM-FILE are omitted. If all of the changes are deletions, the lines 704of TO-FILE are omitted. 705 706 707File: diffutils.info, Node: Unified Format, Next: Sections, Prev: Context Format, Up: Context 708 7092.2.2 Unified Format 710-------------------- 711 712The unified output format is a variation on the context format that is 713more compact because it omits redundant context lines. To select this 714output format, use the '--unified[=LINES]' ('-U LINES'), or '-u' option. 715The argument LINES is the number of lines of context to show. When it 716is not given, it defaults to three. 717 718 At present, only GNU 'diff' can produce this format and only GNU 719'patch' can automatically apply diffs in this format. For proper 720operation, 'patch' typically needs at least three lines of context. 721 722* Menu: 723 724* Example Unified:: Sample output in unified format. 725* Detailed Unified:: A detailed description of unified format. 726 727 728File: diffutils.info, Node: Example Unified, Next: Detailed Unified, Up: Unified Format 729 7302.2.2.1 An Example of Unified Format 731.................................... 732 733Here is the output of the command 'diff -u lao tzu' (*note Sample diff 734Input::, for the complete contents of the two files): 735 736 --- lao 2002-02-21 23:30:39.942229878 -0800 737 +++ tzu 2002-02-21 23:30:50.442260588 -0800 738 @@ -1,7 +1,6 @@ 739 -The Way that can be told of is not the eternal Way; 740 -The name that can be named is not the eternal name. 741 The Nameless is the origin of Heaven and Earth; 742 -The Named is the mother of all things. 743 +The named is the mother of all things. 744 + 745 Therefore let there always be non-being, 746 so we may see their subtlety, 747 And let there always be being, 748 @@ -9,3 +8,6 @@ 749 The two are the same, 750 But after they are produced, 751 they have different names. 752 +They both may be called deep and profound. 753 +Deeper and more profound, 754 +The door of all subtleties! 755 756 757File: diffutils.info, Node: Detailed Unified, Prev: Example Unified, Up: Unified Format 758 7592.2.2.2 Detailed Description of Unified Format 760.............................................. 761 762The unified output format starts with a two-line header, which looks 763like this: 764 765 --- FROM-FILE FROM-FILE-MODIFICATION-TIME 766 +++ TO-FILE TO-FILE-MODIFICATION-TIME 767 768The timestamp looks like '2002-02-21 23:30:39.942229878 -0800' to 769indicate the date, time with fractional seconds, and time zone. The 770fractional seconds are omitted on hosts that do not support fractional 771timestamps. 772 773 You can change the header's content with the '--label=LABEL' option. 774*Note Alternate Names::. 775 776 Next come one or more hunks of differences; each hunk shows one area 777where the files differ. Unified format hunks look like this: 778 779 @@ FROM-FILE-LINE-NUMBERS TO-FILE-LINE-NUMBERS @@ 780 LINE-FROM-EITHER-FILE 781 LINE-FROM-EITHER-FILE... 782 783 If a hunk contains just one line, only its start line number appears. 784Otherwise its line numbers look like 'START,COUNT'. An empty hunk is 785considered to start at the line that follows the hunk. 786 787 If a hunk and its context contain two or more lines, its line numbers 788look like 'START,COUNT'. Otherwise only its end line number appears. 789An empty hunk is considered to end at the line that precedes the hunk. 790 791 The lines common to both files begin with a space character. The 792lines that actually differ between the two files have one of the 793following indicator characters in the left print column: 794 795'+' 796 A line was added here to the first file. 797 798'-' 799 A line was removed here from the first file. 800 801 802File: diffutils.info, Node: Sections, Next: Alternate Names, Prev: Unified Format, Up: Context 803 8042.2.3 Showing Which Sections Differences Are in 805----------------------------------------------- 806 807Sometimes you might want to know which part of the files each change 808falls in. If the files are source code, this could mean which function 809was changed. If the files are documents, it could mean which chapter or 810appendix was changed. GNU 'diff' can show this by displaying the 811nearest section heading line that precedes the differing lines. Which 812lines are "section headings" is determined by a regular expression. 813 814* Menu: 815 816* Specified Headings:: Showing headings that match regular expressions. 817* C Function Headings:: Showing headings of C functions. 818 819 820File: diffutils.info, Node: Specified Headings, Next: C Function Headings, Up: Sections 821 8222.2.3.1 Showing Lines That Match Regular Expressions 823.................................................... 824 825To show in which sections differences occur for files that are not 826source code for C or similar languages, use the 827'--show-function-line=REGEXP' ('-F REGEXP') option. 'diff' considers 828lines that match the 'grep'-style regular expression REGEXP to be the 829beginning of a section of the file. Here are suggested regular 830expressions for some common languages: 831 832'^[[:alpha:]$_]' 833 C, C++, Prolog 834'^(' 835 Lisp 836'^@node' 837 Texinfo 838 839 This option does not automatically select an output format; in order 840to use it, you must select the context format (*note Context Format::) 841or unified format (*note Unified Format::). In other output formats it 842has no effect. 843 844 The '--show-function-line' ('-F') option finds the nearest unchanged 845line that precedes each hunk of differences and matches the given 846regular expression. Then it adds that line to the end of the line of 847asterisks in the context format, or to the '@@' line in unified format. 848If no matching line exists, this option leaves the output for that hunk 849unchanged. If that line is more than 40 characters long, it outputs 850only the first 40 characters. You can specify more than one regular 851expression for such lines; 'diff' tries to match each line against each 852regular expression, starting with the last one given. This means that 853you can use '-p' and '-F' together, if you wish. 854 855 856File: diffutils.info, Node: C Function Headings, Prev: Specified Headings, Up: Sections 857 8582.2.3.2 Showing C Function Headings 859................................... 860 861To show in which functions differences occur for C and similar 862languages, you can use the '--show-c-function' ('-p') option. This 863option automatically defaults to the context output format (*note 864Context Format::), with the default number of lines of context. You can 865override that number with '-C LINES' elsewhere in the command line. You 866can override both the format and the number with '-U LINES' elsewhere in 867the command line. 868 869 The '--show-c-function' ('-p') option is equivalent to '-F 870'^[[:alpha:]$_]'' if the unified format is specified, otherwise '-c -F 871'^[[:alpha:]$_]'' (*note Specified Headings::). GNU 'diff' provides 872this option for the sake of convenience. 873 874 875File: diffutils.info, Node: Alternate Names, Prev: Sections, Up: Context 876 8772.2.4 Showing Alternate File Names 878---------------------------------- 879 880If you are comparing two files that have meaningless or uninformative 881names, you might want 'diff' to show alternate names in the header of 882the context and unified output formats. To do this, use the 883'--label=LABEL' option. The first time you give this option, its 884argument replaces the name and date of the first file in the header; the 885second time, its argument replaces the name and date of the second file. 886If you give this option more than twice, 'diff' reports an error. The 887'--label' option does not affect the file names in the 'pr' header when 888the '-l' or '--paginate' option is used (*note Pagination::). 889 890 Here are the first two lines of the output from 'diff -C 2 891--label=original --label=modified lao tzu': 892 893 *** original 894 --- modified 895 896 897File: diffutils.info, Node: Side by Side, Next: Normal, Prev: Context, Up: Output Formats 898 8992.3 Showing Differences Side by Side 900==================================== 901 902'diff' can produce a side by side difference listing of two files. The 903files are listed in two columns with a gutter between them. The gutter 904contains one of the following markers: 905 906white space 907 The corresponding lines are in common. That is, either the lines 908 are identical, or the difference is ignored because of one of the 909 '--ignore' options (*note White Space::). 910 911'|' 912 The corresponding lines differ, and they are either both complete 913 or both incomplete. 914 915'<' 916 The files differ and only the first file contains the line. 917 918'>' 919 The files differ and only the second file contains the line. 920 921'(' 922 Only the first file contains the line, but the difference is 923 ignored. 924 925')' 926 Only the second file contains the line, but the difference is 927 ignored. 928 929'\' 930 The corresponding lines differ, and only the first line is 931 incomplete. 932 933'/' 934 The corresponding lines differ, and only the second line is 935 incomplete. 936 937 Normally, an output line is incomplete if and only if the lines that 938it contains are incomplete. *Note Incomplete Lines::. However, when an 939output line represents two differing lines, one might be incomplete 940while the other is not. In this case, the output line is complete, but 941its the gutter is marked '\' if the first line is incomplete, '/' if the 942second line is. 943 944 Side by side format is sometimes easiest to read, but it has 945limitations. It generates much wider output than usual, and truncates 946lines that are too long to fit. Also, it relies on lining up output 947more heavily than usual, so its output looks particularly bad if you use 948varying width fonts, nonstandard tab stops, or nonprinting characters. 949 950 You can use the 'sdiff' command to interactively merge side by side 951differences. *Note Interactive Merging::, for more information on 952merging files. 953 954* Menu: 955 956* Side by Side Format:: Controlling side by side output format. 957* Example Side by Side:: Sample side by side output. 958 959 960File: diffutils.info, Node: Side by Side Format, Next: Example Side by Side, Up: Side by Side 961 9622.3.1 Controlling Side by Side Format 963------------------------------------- 964 965The '--side-by-side' ('-y') option selects side by side format. Because 966side by side output lines contain two input lines, the output is wider 967than usual: normally 130 print columns, which can fit onto a traditional 968printer line. You can set the width of the output with the 969'--width=COLUMNS' ('-W COLUMNS') option. The output is split into two 970halves of equal width, separated by a small gutter to mark differences; 971the right half is aligned to a tab stop so that tabs line up. Input 972lines that are too long to fit in half of an output line are truncated 973for output. 974 975 The '--left-column' option prints only the left column of two common 976lines. The '--suppress-common-lines' option suppresses common lines 977entirely. 978 979 980File: diffutils.info, Node: Example Side by Side, Prev: Side by Side Format, Up: Side by Side 981 9822.3.2 An Example of Side by Side Format 983--------------------------------------- 984 985Here is the output of the command 'diff -y -W 72 lao tzu' (*note Sample 986diff Input::, for the complete contents of the two files). 987 988 The Way that can be told of is n < 989 The name that can be named is no < 990 The Nameless is the origin of He The Nameless is the origin of He 991 The Named is the mother of all t | The named is the mother of all t 992 > 993 Therefore let there always be no Therefore let there always be no 994 so we may see their subtlety, so we may see their subtlety, 995 And let there always be being, And let there always be being, 996 so we may see their outcome. so we may see their outcome. 997 The two are the same, The two are the same, 998 But after they are produced, But after they are produced, 999 they have different names. they have different names. 1000 > They both may be called deep and 1001 > Deeper and more profound, 1002 > The door of all subtleties! 1003 1004 1005File: diffutils.info, Node: Normal, Next: Scripts, Prev: Side by Side, Up: Output Formats 1006 10072.4 Showing Differences Without Context 1008======================================= 1009 1010The "normal" 'diff' output format shows each hunk of differences without 1011any surrounding context. Sometimes such output is the clearest way to 1012see how lines have changed, without the clutter of nearby unchanged 1013lines (although you can get similar results with the context or unified 1014formats by using 0 lines of context). However, this format is no longer 1015widely used for sending out patches; for that purpose, the context 1016format (*note Context Format::) and the unified format (*note Unified 1017Format::) are superior. Normal format is the default for compatibility 1018with older versions of 'diff' and the POSIX standard. Use the 1019'--normal' option to select this output format explicitly. 1020 1021* Menu: 1022 1023* Example Normal:: Sample output in the normal format. 1024* Detailed Normal:: A detailed description of normal output format. 1025 1026 1027File: diffutils.info, Node: Example Normal, Next: Detailed Normal, Up: Normal 1028 10292.4.1 An Example of Normal Format 1030--------------------------------- 1031 1032Here is the output of the command 'diff lao tzu' (*note Sample diff 1033Input::, for the complete contents of the two files). Notice that it 1034shows only the lines that are different between the two files. 1035 1036 1,2d0 1037 < The Way that can be told of is not the eternal Way; 1038 < The name that can be named is not the eternal name. 1039 4c2,3 1040 < The Named is the mother of all things. 1041 --- 1042 > The named is the mother of all things. 1043 > 1044 11a11,13 1045 > They both may be called deep and profound. 1046 > Deeper and more profound, 1047 > The door of all subtleties! 1048 1049 1050File: diffutils.info, Node: Detailed Normal, Prev: Example Normal, Up: Normal 1051 10522.4.2 Detailed Description of Normal Format 1053------------------------------------------- 1054 1055The normal output format consists of one or more hunks of differences; 1056each hunk shows one area where the files differ. Normal format hunks 1057look like this: 1058 1059 CHANGE-COMMAND 1060 < FROM-FILE-LINE 1061 < FROM-FILE-LINE... 1062 --- 1063 > TO-FILE-LINE 1064 > TO-FILE-LINE... 1065 1066 There are three types of change commands. Each consists of a line 1067number or comma-separated range of lines in the first file, a single 1068character indicating the kind of change to make, and a line number or 1069comma-separated range of lines in the second file. All line numbers are 1070the original line numbers in each file. The types of change commands 1071are: 1072 1073'LaR' 1074 Add the lines in range R of the second file after line L of the 1075 first file. For example, '8a12,15' means append lines 12-15 of 1076 file 2 after line 8 of file 1; or, if changing file 2 into file 1, 1077 delete lines 12-15 of file 2. 1078 1079'FcT' 1080 Replace the lines in range F of the first file with lines in range 1081 T of the second file. This is like a combined add and delete, but 1082 more compact. For example, '5,7c8,10' means change lines 5-7 of 1083 file 1 to read as lines 8-10 of file 2; or, if changing file 2 into 1084 file 1, change lines 8-10 of file 2 to read as lines 5-7 of file 1. 1085 1086'RdL' 1087 Delete the lines in range R from the first file; line L is where 1088 they would have appeared in the second file had they not been 1089 deleted. For example, '5,7d3' means delete lines 5-7 of file 1; 1090 or, if changing file 2 into file 1, append lines 5-7 of file 1 1091 after line 3 of file 2. 1092 1093 1094File: diffutils.info, Node: Scripts, Next: If-then-else, Prev: Normal, Up: Output Formats 1095 10962.5 Making Edit Scripts 1097======================= 1098 1099Several output modes produce command scripts for editing FROM-FILE to 1100produce TO-FILE. 1101 1102* Menu: 1103 1104* ed Scripts:: Using 'diff' to produce commands for 'ed'. 1105* Forward ed:: Making forward 'ed' scripts. 1106* RCS:: A special 'diff' output format used by RCS. 1107 1108 1109File: diffutils.info, Node: ed Scripts, Next: Forward ed, Up: Scripts 1110 11112.5.1 'ed' Scripts 1112------------------ 1113 1114'diff' can produce commands that direct the 'ed' text editor to change 1115the first file into the second file. Long ago, this was the only output 1116mode that was suitable for editing one file into another automatically; 1117today, with 'patch', it is almost obsolete. Use the '--ed' ('-e') 1118option to select this output format. 1119 1120 Like the normal format (*note Normal::), this output format does not 1121show any context; unlike the normal format, it does not include the 1122information necessary to apply the diff in reverse (to produce the first 1123file if all you have is the second file and the diff). 1124 1125 If the file 'd' contains the output of 'diff -e old new', then the 1126command '(cat d && echo w) | ed - old' edits 'old' to make it a copy of 1127'new'. More generally, if 'd1', 'd2', ..., 'dN' contain the outputs of 1128'diff -e old new1', 'diff -e new1 new2', ..., 'diff -e newN-1 newN', 1129respectively, then the command '(cat d1 d2 ... dN && echo w) | ed - old' 1130edits 'old' to make it a copy of 'newN'. 1131 1132* Menu: 1133 1134* Example ed:: A sample 'ed' script. 1135* Detailed ed:: A detailed description of 'ed' format. 1136 1137 1138File: diffutils.info, Node: Example ed, Next: Detailed ed, Up: ed Scripts 1139 11402.5.1.1 Example 'ed' Script 1141........................... 1142 1143Here is the output of 'diff -e lao tzu' (*note Sample diff Input::, for 1144the complete contents of the two files): 1145 1146 11a 1147 They both may be called deep and profound. 1148 Deeper and more profound, 1149 The door of all subtleties! 1150 . 1151 4c 1152 The named is the mother of all things. 1153 1154 . 1155 1,2d 1156 1157 1158File: diffutils.info, Node: Detailed ed, Prev: Example ed, Up: ed Scripts 1159 11602.5.1.2 Detailed Description of 'ed' Format 1161........................................... 1162 1163The 'ed' output format consists of one or more hunks of differences. 1164The changes closest to the ends of the files come first so that commands 1165that change the number of lines do not affect how 'ed' interprets line 1166numbers in succeeding commands. 'ed' format hunks look like this: 1167 1168 CHANGE-COMMAND 1169 TO-FILE-LINE 1170 TO-FILE-LINE... 1171 . 1172 1173 Because 'ed' uses a single period on a line to indicate the end of 1174input, GNU 'diff' protects lines of changes that contain a single period 1175on a line by writing two periods instead, then writing a subsequent 'ed' 1176command to change the two periods into one. The 'ed' format cannot 1177represent an incomplete line, so if the second file ends in a changed 1178incomplete line, 'diff' reports an error and then pretends that a 1179newline was appended. 1180 1181 There are three types of change commands. Each consists of a line 1182number or comma-separated range of lines in the first file and a single 1183character indicating the kind of change to make. All line numbers are 1184the original line numbers in the file. The types of change commands 1185are: 1186 1187'La' 1188 Add text from the second file after line L in the first file. For 1189 example, '8a' means to add the following lines after line 8 of file 1190 1. 1191 1192'Rc' 1193 Replace the lines in range R in the first file with the following 1194 lines. Like a combined add and delete, but more compact. For 1195 example, '5,7c' means change lines 5-7 of file 1 to read as the 1196 text file 2. 1197 1198'Rd' 1199 Delete the lines in range R from the first file. For example, 1200 '5,7d' means delete lines 5-7 of file 1. 1201 1202 1203File: diffutils.info, Node: Forward ed, Next: RCS, Prev: ed Scripts, Up: Scripts 1204 12052.5.2 Forward 'ed' Scripts 1206-------------------------- 1207 1208'diff' can produce output that is like an 'ed' script, but with hunks in 1209forward (front to back) order. The format of the commands is also 1210changed slightly: command characters precede the lines they modify, 1211spaces separate line numbers in ranges, and no attempt is made to 1212disambiguate hunk lines consisting of a single period. Like 'ed' 1213format, forward 'ed' format cannot represent incomplete lines. 1214 1215 Forward 'ed' format is not very useful, because neither 'ed' nor 1216'patch' can apply diffs in this format. It exists mainly for 1217compatibility with older versions of 'diff'. Use the '-f' or 1218'--forward-ed' option to select it. 1219 1220 1221File: diffutils.info, Node: RCS, Prev: Forward ed, Up: Scripts 1222 12232.5.3 RCS Scripts 1224----------------- 1225 1226The RCS output format is designed specifically for use by the Revision 1227Control System, which is a set of free programs used for organizing 1228different versions and systems of files. Use the '--rcs' ('-n') option 1229to select this output format. It is like the forward 'ed' format (*note 1230Forward ed::), but it can represent arbitrary changes to the contents of 1231a file because it avoids the forward 'ed' format's problems with lines 1232consisting of a single period and with incomplete lines. Instead of 1233ending text sections with a line consisting of a single period, each 1234command specifies the number of lines it affects; a combination of the 1235'a' and 'd' commands are used instead of 'c'. Also, if the second file 1236ends in a changed incomplete line, then the output also ends in an 1237incomplete line. 1238 1239 Here is the output of 'diff -n lao tzu' (*note Sample diff Input::, 1240for the complete contents of the two files): 1241 1242 d1 2 1243 d4 1 1244 a4 2 1245 The named is the mother of all things. 1246 1247 a11 3 1248 They both may be called deep and profound. 1249 Deeper and more profound, 1250 The door of all subtleties! 1251 1252 1253File: diffutils.info, Node: If-then-else, Prev: Scripts, Up: Output Formats 1254 12552.6 Merging Files with If-then-else 1256=================================== 1257 1258You can use 'diff' to merge two files of C source code. The output of 1259'diff' in this format contains all the lines of both files. Lines 1260common to both files are output just once; the differing parts are 1261separated by the C preprocessor directives '#ifdef NAME' or '#ifndef 1262NAME', '#else', and '#endif'. When compiling the output, you select 1263which version to use by either defining or leaving undefined the macro 1264NAME. 1265 1266 To merge two files, use 'diff' with the '-D NAME' or '--ifdef=NAME' 1267option. The argument NAME is the C preprocessor identifier to use in 1268the '#ifdef' and '#ifndef' directives. 1269 1270 For example, if you change an instance of 'wait (&s)' to 'waitpid 1271(-1, &s, 0)' and then merge the old and new files with the 1272'--ifdef=HAVE_WAITPID' option, then the affected part of your code might 1273look like this: 1274 1275 do { 1276 #ifndef HAVE_WAITPID 1277 if ((w = wait (&s)) < 0 && errno != EINTR) 1278 #else /* HAVE_WAITPID */ 1279 if ((w = waitpid (-1, &s, 0)) < 0 && errno != EINTR) 1280 #endif /* HAVE_WAITPID */ 1281 return w; 1282 } while (w != child); 1283 1284 You can specify formats for languages other than C by using line 1285group formats and line formats, as described in the next sections. 1286 1287* Menu: 1288 1289* Line Group Formats:: Formats for general if-then-else line groups. 1290* Line Formats:: Formats for each line in a line group. 1291* Example If-then-else:: Sample if-then-else format output. 1292* Detailed If-then-else:: A detailed description of if-then-else format. 1293 1294 1295File: diffutils.info, Node: Line Group Formats, Next: Line Formats, Up: If-then-else 1296 12972.6.1 Line Group Formats 1298------------------------ 1299 1300Line group formats let you specify formats suitable for many 1301applications that allow if-then-else input, including programming 1302languages and text formatting languages. A line group format specifies 1303the output format for a contiguous group of similar lines. 1304 1305 For example, the following command compares the TeX files 'old' and 1306'new', and outputs a merged file in which old regions are surrounded by 1307'\begin{em}'-'\end{em}' lines, and new regions are surrounded by 1308'\begin{bf}'-'\end{bf}' lines. 1309 1310 diff \ 1311 --old-group-format='\begin{em} 1312 %<\end{em} 1313 ' \ 1314 --new-group-format='\begin{bf} 1315 %>\end{bf} 1316 ' \ 1317 old new 1318 1319 The following command is equivalent to the above example, but it is a 1320little more verbose, because it spells out the default line group 1321formats. 1322 1323 diff \ 1324 --old-group-format='\begin{em} 1325 %<\end{em} 1326 ' \ 1327 --new-group-format='\begin{bf} 1328 %>\end{bf} 1329 ' \ 1330 --unchanged-group-format='%=' \ 1331 --changed-group-format='\begin{em} 1332 %<\end{em} 1333 \begin{bf} 1334 %>\end{bf} 1335 ' \ 1336 old new 1337 1338 Here is a more advanced example, which outputs a diff listing with 1339headers containing line numbers in a "plain English" style. 1340 1341 diff \ 1342 --unchanged-group-format='' \ 1343 --old-group-format='-------- %dn line%(n=1?:s) deleted at %df: 1344 %<' \ 1345 --new-group-format='-------- %dN line%(N=1?:s) added after %de: 1346 %>' \ 1347 --changed-group-format='-------- %dn line%(n=1?:s) changed at %df: 1348 %<-------- to: 1349 %>' \ 1350 old new 1351 1352 To specify a line group format, use 'diff' with one of the options 1353listed below. You can specify up to four line group formats, one for 1354each kind of line group. You should quote FORMAT, because it typically 1355contains shell metacharacters. 1356 1357'--old-group-format=FORMAT' 1358 These line groups are hunks containing only lines from the first 1359 file. The default old group format is the same as the changed 1360 group format if it is specified; otherwise it is a format that 1361 outputs the line group as-is. 1362 1363'--new-group-format=FORMAT' 1364 These line groups are hunks containing only lines from the second 1365 file. The default new group format is same as the changed group 1366 format if it is specified; otherwise it is a format that outputs 1367 the line group as-is. 1368 1369'--changed-group-format=FORMAT' 1370 These line groups are hunks containing lines from both files. The 1371 default changed group format is the concatenation of the old and 1372 new group formats. 1373 1374'--unchanged-group-format=FORMAT' 1375 These line groups contain lines common to both files. The default 1376 unchanged group format is a format that outputs the line group 1377 as-is. 1378 1379 In a line group format, ordinary characters represent themselves; 1380conversion specifications start with '%' and have one of the following 1381forms. 1382 1383'%<' 1384 stands for the lines from the first file, including the trailing 1385 newline. Each line is formatted according to the old line format 1386 (*note Line Formats::). 1387 1388'%>' 1389 stands for the lines from the second file, including the trailing 1390 newline. Each line is formatted according to the new line format. 1391 1392'%=' 1393 stands for the lines common to both files, including the trailing 1394 newline. Each line is formatted according to the unchanged line 1395 format. 1396 1397'%%' 1398 stands for '%'. 1399 1400'%c'C'' 1401 where C is a single character, stands for C. C may not be a 1402 backslash or an apostrophe. For example, '%c':'' stands for a 1403 colon, even inside the then-part of an if-then-else format, which a 1404 colon would normally terminate. 1405 1406'%c'\O'' 1407 where O is a string of 1, 2, or 3 octal digits, stands for the 1408 character with octal code O. For example, '%c'\0'' stands for a 1409 null character. 1410 1411'FN' 1412 where F is a 'printf' conversion specification and N is one of the 1413 following letters, stands for N's value formatted with F. 1414 1415 'e' 1416 The line number of the line just before the group in the old 1417 file. 1418 1419 'f' 1420 The line number of the first line in the group in the old 1421 file; equals E + 1. 1422 1423 'l' 1424 The line number of the last line in the group in the old file. 1425 1426 'm' 1427 The line number of the line just after the group in the old 1428 file; equals L + 1. 1429 1430 'n' 1431 The number of lines in the group in the old file; equals L - F 1432 + 1. 1433 1434 'E, F, L, M, N' 1435 Likewise, for lines in the new file. 1436 1437 The 'printf' conversion specification can be '%d', '%o', '%x', or 1438 '%X', specifying decimal, octal, lower case hexadecimal, or upper 1439 case hexadecimal output respectively. After the '%' the following 1440 options can appear in sequence: a series of zero or more flags; an 1441 integer specifying the minimum field width; and a period followed 1442 by an optional integer specifying the minimum number of digits. 1443 The flags are '-' for left-justification, ''' for separating the 1444 digit into groups as specified by the 'LC_NUMERIC' locale category, 1445 and '0' for padding with zeros instead of spaces. For example, 1446 '%5dN' prints the number of new lines in the group in a field of 1447 width 5 characters, using the 'printf' format '"%5d"'. 1448 1449'(A=B?T:E)' 1450 If A equals B then T else E. A and B are each either a decimal 1451 constant or a single letter interpreted as above. This format spec 1452 is equivalent to T if A's value equals B's; otherwise it is 1453 equivalent to E. 1454 1455 For example, '%(N=0?no:%dN) line%(N=1?:s)' is equivalent to 'no 1456 lines' if N (the number of lines in the group in the new file) is 1457 0, to '1 line' if N is 1, and to '%dN lines' otherwise. 1458 1459 1460File: diffutils.info, Node: Line Formats, Next: Example If-then-else, Prev: Line Group Formats, Up: If-then-else 1461 14622.6.2 Line Formats 1463------------------ 1464 1465Line formats control how each line taken from an input file is output as 1466part of a line group in if-then-else format. 1467 1468 For example, the following command outputs text with a one-character 1469change indicator to the left of the text. The first character of output 1470is '-' for deleted lines, '|' for added lines, and a space for unchanged 1471lines. The formats contain newline characters where newlines are 1472desired on output. 1473 1474 diff \ 1475 --old-line-format='-%l 1476 ' \ 1477 --new-line-format='|%l 1478 ' \ 1479 --unchanged-line-format=' %l 1480 ' \ 1481 old new 1482 1483 To specify a line format, use one of the following options. You 1484should quote FORMAT, since it often contains shell metacharacters. 1485 1486'--old-line-format=FORMAT' 1487 formats lines just from the first file. 1488 1489'--new-line-format=FORMAT' 1490 formats lines just from the second file. 1491 1492'--unchanged-line-format=FORMAT' 1493 formats lines common to both files. 1494 1495'--line-format=FORMAT' 1496 formats all lines; in effect, it sets all three above options 1497 simultaneously. 1498 1499 In a line format, ordinary characters represent themselves; 1500conversion specifications start with '%' and have one of the following 1501forms. 1502 1503'%l' 1504 stands for the contents of the line, not counting its trailing 1505 newline (if any). This format ignores whether the line is 1506 incomplete; *Note Incomplete Lines::. 1507 1508'%L' 1509 stands for the contents of the line, including its trailing newline 1510 (if any). If a line is incomplete, this format preserves its 1511 incompleteness. 1512 1513'%%' 1514 stands for '%'. 1515 1516'%c'C'' 1517 where C is a single character, stands for C. C may not be a 1518 backslash or an apostrophe. For example, '%c':'' stands for a 1519 colon. 1520 1521'%c'\O'' 1522 where O is a string of 1, 2, or 3 octal digits, stands for the 1523 character with octal code O. For example, '%c'\0'' stands for a 1524 null character. 1525 1526'Fn' 1527 where F is a 'printf' conversion specification, stands for the line 1528 number formatted with F. For example, '%.5dn' prints the line 1529 number using the 'printf' format '"%.5d"'. *Note Line Group 1530 Formats::, for more about printf conversion specifications. 1531 1532 The default line format is '%l' followed by a newline character. 1533 1534 If the input contains tab characters and it is important that they 1535line up on output, you should ensure that '%l' or '%L' in a line format 1536is just after a tab stop (e.g. by preceding '%l' or '%L' with a tab 1537character), or you should use the '-t' or '--expand-tabs' option. 1538 1539 Taken together, the line and line group formats let you specify many 1540different formats. For example, the following command uses a format 1541similar to normal 'diff' format. You can tailor this command to get 1542fine control over 'diff' output. 1543 1544 diff \ 1545 --old-line-format='< %l 1546 ' \ 1547 --new-line-format='> %l 1548 ' \ 1549 --old-group-format='%df%(f=l?:,%dl)d%dE 1550 %<' \ 1551 --new-group-format='%dea%dF%(F=L?:,%dL) 1552 %>' \ 1553 --changed-group-format='%df%(f=l?:,%dl)c%dF%(F=L?:,%dL) 1554 %<--- 1555 %>' \ 1556 --unchanged-group-format='' \ 1557 old new 1558 1559 1560File: diffutils.info, Node: Example If-then-else, Next: Detailed If-then-else, Prev: Line Formats, Up: If-then-else 1561 15622.6.3 An Example of If-then-else Format 1563--------------------------------------- 1564 1565Here is the output of 'diff -DTWO lao tzu' (*note Sample diff Input::, 1566for the complete contents of the two files): 1567 1568 #ifndef TWO 1569 The Way that can be told of is not the eternal Way; 1570 The name that can be named is not the eternal name. 1571 #endif /* ! TWO */ 1572 The Nameless is the origin of Heaven and Earth; 1573 #ifndef TWO 1574 The Named is the mother of all things. 1575 #else /* TWO */ 1576 The named is the mother of all things. 1577 1578 #endif /* TWO */ 1579 Therefore let there always be non-being, 1580 so we may see their subtlety, 1581 And let there always be being, 1582 so we may see their outcome. 1583 The two are the same, 1584 But after they are produced, 1585 they have different names. 1586 #ifdef TWO 1587 They both may be called deep and profound. 1588 Deeper and more profound, 1589 The door of all subtleties! 1590 #endif /* TWO */ 1591 1592 1593File: diffutils.info, Node: Detailed If-then-else, Prev: Example If-then-else, Up: If-then-else 1594 15952.6.4 Detailed Description of If-then-else Format 1596------------------------------------------------- 1597 1598For lines common to both files, 'diff' uses the unchanged line group 1599format. For each hunk of differences in the merged output format, if 1600the hunk contains only lines from the first file, 'diff' uses the old 1601line group format; if the hunk contains only lines from the second file, 1602'diff' uses the new group format; otherwise, 'diff' uses the changed 1603group format. 1604 1605 The old, new, and unchanged line formats specify the output format of 1606lines from the first file, lines from the second file, and lines common 1607to both files, respectively. 1608 1609 The option '--ifdef=NAME' is equivalent to the following sequence of 1610options using shell syntax: 1611 1612 --old-group-format='#ifndef NAME 1613 %<#endif /* ! NAME */ 1614 ' \ 1615 --new-group-format='#ifdef NAME 1616 %>#endif /* NAME */ 1617 ' \ 1618 --unchanged-group-format='%=' \ 1619 --changed-group-format='#ifndef NAME 1620 %<#else /* NAME */ 1621 %>#endif /* NAME */ 1622 ' 1623 1624 You should carefully check the 'diff' output for proper nesting. For 1625example, when using the '-D NAME' or '--ifdef=NAME' option, you should 1626check that if the differing lines contain any of the C preprocessor 1627directives '#ifdef', '#ifndef', '#else', '#elif', or '#endif', they are 1628nested properly and match. If they don't, you must make corrections 1629manually. It is a good idea to carefully check the resulting code 1630anyway to make sure that it really does what you want it to; depending 1631on how the input files were produced, the output might contain duplicate 1632or otherwise incorrect code. 1633 1634 The 'patch' '-D NAME' option behaves like the 'diff' '-D NAME' 1635option, except it operates on a file and a diff to produce a merged 1636file. *Note patch Options::. 1637 1638 1639File: diffutils.info, Node: Incomplete Lines, Next: Comparing Directories, Prev: Output Formats, Up: Top 1640 16413 Incomplete Lines 1642****************** 1643 1644When an input file ends in a non-newline character, its last line is 1645called an "incomplete line" because its last character is not a newline. 1646All other lines are called "full lines" and end in a newline character. 1647Incomplete lines do not match full lines unless differences in white 1648space are ignored (*note White Space::). 1649 1650 An incomplete line is normally distinguished on output from a full 1651line by a following line that starts with '\'. However, the RCS format 1652(*note RCS::) outputs the incomplete line as-is, without any trailing 1653newline or following line. The side by side format normally represents 1654incomplete lines as-is, but in some cases uses a '\' or '/' gutter 1655marker. *Note Side by Side::. The if-then-else line format preserves a 1656line's incompleteness with '%L', and discards the newline with '%l'. 1657*Note Line Formats::. Finally, with the 'ed' and forward 'ed' output 1658formats (*note Output Formats::) 'diff' cannot represent an incomplete 1659line, so it pretends there was a newline and reports an error. 1660 1661 For example, suppose 'F' and 'G' are one-byte files that contain just 1662'f' and 'g', respectively. Then 'diff F G' outputs 1663 1664 1c1 1665 < f 1666 \ No newline at end of file 1667 --- 1668 > g 1669 \ No newline at end of file 1670 1671(The exact message may differ in non-English locales.) 'diff -n F G' 1672outputs the following without a trailing newline: 1673 1674 d1 1 1675 a1 1 1676 g 1677 1678'diff -e F G' reports two errors and outputs the following: 1679 1680 1c 1681 g 1682 . 1683 1684 1685File: diffutils.info, Node: Comparing Directories, Next: Adjusting Output, Prev: Incomplete Lines, Up: Top 1686 16874 Comparing Directories 1688*********************** 1689 1690You can use 'diff' to compare some or all of the files in two directory 1691trees. When both file name arguments to 'diff' are directories, it 1692compares each file that is contained in both directories, examining file 1693names in alphabetical order as specified by the 'LC_COLLATE' locale 1694category. Normally 'diff' is silent about pairs of files that contain 1695no differences, but if you use the '--report-identical-files' ('-s') 1696option, it reports pairs of identical files. Normally 'diff' reports 1697subdirectories common to both directories without comparing 1698subdirectories' files, but if you use the '-r' or '--recursive' option, 1699it compares every corresponding pair of files in the directory trees, as 1700many levels deep as they go. 1701 1702 If only one file exists, 'diff' normally does not show its contents; 1703it merely reports that one file exists but the other does not. You can 1704make 'diff' act as though the missing file is empty, so that it outputs 1705the entire contents of the file that actually exists. (It is output as 1706either an insertion or a deletion, depending on whether the missing file 1707is in the first or the second position.) To do this, use the 1708'--new-file' ('-N') option. This option affects command-line arguments 1709as well as files found via directory traversal; for example, 'diff -N a 1710b' treats 'a' as empty if 'a' does not exist but 'b' does, and similarly 1711'diff -N - b' treats standard input as empty if it is closed but 'b' 1712exists. 1713 1714 If the older directory contains large files that are not in the newer 1715directory, you can make the patch smaller by using the 1716'--unidirectional-new-file' option instead of '-N'. This option is like 1717'-N' except that it inserts the contents only of files that appear in 1718the second directory but not the first (that is, files that were added). 1719At the top of the patch, write instructions for the user applying the 1720patch to remove the files that were deleted before applying the patch. 1721*Note Making Patches::, for more discussion of making patches for 1722distribution. 1723 1724 To ignore some files while comparing directories, use the 1725'--exclude=PATTERN' ('-x PATTERN') option. This option ignores any 1726files or subdirectories whose base names match the shell pattern 1727PATTERN. Unlike in the shell, a period at the start of the base of a 1728file name matches a wildcard at the start of a pattern. You should 1729enclose PATTERN in quotes so that the shell does not expand it. For 1730example, the option '-x '*.[ao]'' ignores any file whose name ends with 1731'.a' or '.o'. 1732 1733 This option accumulates if you specify it more than once. For 1734example, using the options '-x 'RCS' -x '*,v'' ignores any file or 1735subdirectory whose base name is 'RCS' or ends with ',v'. 1736 1737 If you need to give this option many times, you can instead put the 1738patterns in a file, one pattern per line, and use the 1739'--exclude-from=FILE' ('-X FILE') option. Trailing white space and 1740empty lines are ignored in the pattern file. 1741 1742 If you have been comparing two directories and stopped partway 1743through, later you might want to continue where you left off. You can 1744do this by using the '--starting-file=FILE' ('-S FILE') option. This 1745compares only the file FILE and all alphabetically later files in the 1746topmost directory level. 1747 1748 If two directories differ only in that file names are lower case in 1749one directory and upper case in the upper, 'diff' normally reports many 1750differences because it compares file names in a case sensitive way. 1751With the '--ignore-file-name-case' option, 'diff' ignores case 1752differences in file names, so that for example the contents of the file 1753'Tao' in one directory are compared to the contents of the file 'TAO' in 1754the other. The '--no-ignore-file-name-case' option cancels the effect 1755of the '--ignore-file-name-case' option, reverting to the default 1756behavior. 1757 1758 If an '--exclude=PATTERN' ('-x PATTERN') option, or an 1759'--exclude-from=FILE' ('-X FILE') option, is specified while the 1760'--ignore-file-name-case' option is in effect, case is ignored when 1761excluding file names matching the specified patterns. 1762 1763 To tell 'diff' not to follow a symbolic link, use the 1764'--no-dereference' option. 1765 1766 1767File: diffutils.info, Node: Adjusting Output, Next: diff Performance, Prev: Comparing Directories, Up: Top 1768 17695 Making 'diff' Output Prettier 1770******************************* 1771 1772'diff' provides several ways to adjust the appearance of its output. 1773These adjustments can be applied to any output format. 1774 1775* Menu: 1776 1777* Tabs:: Preserving the alignment of tab stops. 1778* Trailing Blanks:: Suppressing blanks before empty output lines. 1779* Pagination:: Page numbering and time-stamping 'diff' output. 1780 1781 1782File: diffutils.info, Node: Tabs, Next: Trailing Blanks, Up: Adjusting Output 1783 17845.1 Preserving Tab Stop Alignment 1785================================= 1786 1787The lines of text in some of the 'diff' output formats are preceded by 1788one or two characters that indicate whether the text is inserted, 1789deleted, or changed. The addition of those characters can cause tabs to 1790move to the next tab stop, throwing off the alignment of columns in the 1791line. GNU 'diff' provides two ways to make tab-aligned columns line up 1792correctly. 1793 1794 The first way is to have 'diff' convert all tabs into the correct 1795number of spaces before outputting them; select this method with the 1796'--expand-tabs' ('-t') option. To use this form of output with 'patch', 1797you must give 'patch' the '-l' or '--ignore-white-space' option (*note 1798Changed White Space::, for more information). 'diff' normally assumes 1799that tab stops are set every 8 print columns, but this can be altered by 1800the '--tabsize=COLUMNS' option. 1801 1802 The other method for making tabs line up correctly is to add a tab 1803character instead of a space after the indicator character at the 1804beginning of the line. This ensures that all following tab characters 1805are in the same position relative to tab stops that they were in the 1806original files, so that the output is aligned correctly. Its 1807disadvantage is that it can make long lines too long to fit on one line 1808of the screen or the paper. It also does not work with the unified 1809output format, which does not have a space character after the change 1810type indicator character. Select this method with the '-T' or 1811'--initial-tab' option. 1812 1813 1814File: diffutils.info, Node: Trailing Blanks, Next: Pagination, Prev: Tabs, Up: Adjusting Output 1815 18165.2 Omitting trailing blanks 1817============================ 1818 1819When outputting lines in normal or context format, or outputting an 1820unchanged line in unified format, 'diff' normally outputs a blank just 1821before each line. If the line is empty, the output of 'diff' therefore 1822contains trailing blanks even though the input does not contain them. 1823For example, when outputting an unchanged empty line in context format, 1824'diff' normally outputs a line with two leading spaces. 1825 1826 Some text editors and email agents routinely delete trailing blanks, 1827so it can be a problem to deal with diff output files that contain them. 1828You can avoid this problem with the '--suppress-blank-empty' option. It 1829causes 'diff' to omit trailing blanks at the end of output lines in 1830normal, context, and unified format, unless the trailing blanks were 1831already present in the input. This changes the output format slightly, 1832so that output lines are guaranteed to never end in a blank unless an 1833input line ends in a blank. This format is less likely to be munged by 1834text editors or by transmission via email. It is accepted by GNU 1835'patch' as well. 1836 1837 1838File: diffutils.info, Node: Pagination, Prev: Trailing Blanks, Up: Adjusting Output 1839 18405.3 Paginating 'diff' Output 1841============================ 1842 1843It can be convenient to have long output page-numbered and time-stamped. 1844The '--paginate' ('-l') option does this by sending the 'diff' output 1845through the 'pr' program. Here is what the page header might look like 1846for 'diff -lc lao tzu': 1847 1848 2002-02-22 14:20 diff -lc lao tzu Page 1 1849 1850 1851File: diffutils.info, Node: diff Performance, Next: Comparing Three Files, Prev: Adjusting Output, Up: Top 1852 18536 'diff' Performance Tradeoffs 1854****************************** 1855 1856GNU 'diff' runs quite efficiently; however, in some circumstances you 1857can cause it to run faster or produce a more compact set of changes. 1858 1859 One way to improve 'diff' performance is to use hard or symbolic 1860links to files instead of copies. This improves performance because 1861'diff' normally does not need to read two hard or symbolic links to the 1862same file, since their contents must be identical. For example, suppose 1863you copy a large directory hierarchy, make a few changes to the copy, 1864and then often use 'diff -r' to compare the original to the copy. If 1865the original files are read-only, you can greatly improve performance by 1866creating the copy using hard or symbolic links (e.g., with GNU 'cp -lR' 1867or 'cp -sR'). Before editing a file in the copy for the first time, you 1868should break the link and replace it with a regular copy. 1869 1870 You can also affect the performance of GNU 'diff' by giving it 1871options that change the way it compares files. Performance has more 1872than one dimension. These options improve one aspect of performance at 1873the cost of another, or they improve performance in some cases while 1874hurting it in others. 1875 1876 The way that GNU 'diff' determines which lines have changed always 1877comes up with a near-minimal set of differences. Usually it is good 1878enough for practical purposes. If the 'diff' output is large, you might 1879want 'diff' to use a modified algorithm that sometimes produces a 1880smaller set of differences. The '--minimal' ('-d') option does this; 1881however, it can also cause 'diff' to run more slowly than usual, so it 1882is not the default behavior. 1883 1884 When the files you are comparing are large and have small groups of 1885changes scattered throughout them, you can use the '--speed-large-files' 1886option to make a different modification to the algorithm that 'diff' 1887uses. If the input files have a constant small density of changes, this 1888option speeds up the comparisons without changing the output. If not, 1889'diff' might produce a larger set of differences; however, the output 1890will still be correct. 1891 1892 Normally 'diff' discards the prefix and suffix that is common to both 1893files before it attempts to find a minimal set of differences. This 1894makes 'diff' run faster, but occasionally it may produce non-minimal 1895output. The '--horizon-lines=LINES' option prevents 'diff' from 1896discarding the last LINES lines of the prefix and the first LINES lines 1897of the suffix. This gives 'diff' further opportunities to find a 1898minimal output. 1899 1900 Suppose a run of changed lines includes a sequence of lines at one 1901end and there is an identical sequence of lines just outside the other 1902end. The 'diff' command is free to choose which identical sequence is 1903included in the hunk. In this case, 'diff' normally shifts the hunk's 1904boundaries when this merges adjacent hunks, or shifts a hunk's lines 1905towards the end of the file. Merging hunks can make the output look 1906nicer in some cases. 1907 1908 1909File: diffutils.info, Node: Comparing Three Files, Next: diff3 Merging, Prev: diff Performance, Up: Top 1910 19117 Comparing Three Files 1912*********************** 1913 1914Use the program 'diff3' to compare three files and show any differences 1915among them. ('diff3' can also merge files; see *note diff3 Merging::). 1916 1917 The "normal" 'diff3' output format shows each hunk of differences 1918without surrounding context. Hunks are labeled depending on whether 1919they are two-way or three-way, and lines are annotated by their location 1920in the input files. 1921 1922 *Note Invoking diff3::, for more information on how to run 'diff3'. 1923 1924* Menu: 1925 1926* Sample diff3 Input:: Sample 'diff3' input for examples. 1927* Example diff3 Normal:: Sample output in the normal format. 1928* Detailed diff3 Normal:: A detailed description of normal output format. 1929* diff3 Hunks:: The format of normal output format. 1930 1931 1932File: diffutils.info, Node: Sample diff3 Input, Next: Example diff3 Normal, Up: Comparing Three Files 1933 19347.1 A Third Sample Input File 1935============================= 1936 1937Here is a third sample file that will be used in examples to illustrate 1938the output of 'diff3' and how various options can change it. The first 1939two files are the same that we used for 'diff' (*note Sample diff 1940Input::). This is the third sample file, called 'tao': 1941 1942 The Way that can be told of is not the eternal Way; 1943 The name that can be named is not the eternal name. 1944 The Nameless is the origin of Heaven and Earth; 1945 The named is the mother of all things. 1946 1947 Therefore let there always be non-being, 1948 so we may see their subtlety, 1949 And let there always be being, 1950 so we may see their result. 1951 The two are the same, 1952 But after they are produced, 1953 they have different names. 1954 1955 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 1956 1957 1958File: diffutils.info, Node: Example diff3 Normal, Next: Detailed diff3 Normal, Prev: Sample diff3 Input, Up: Comparing Three Files 1959 19607.2 An Example of 'diff3' Normal Format 1961======================================= 1962 1963Here is the output of the command 'diff3 lao tzu tao' (*note Sample 1964diff3 Input::, for the complete contents of the files). Notice that it 1965shows only the lines that are different among the three files. 1966 1967 ====2 1968 1:1,2c 1969 3:1,2c 1970 The Way that can be told of is not the eternal Way; 1971 The name that can be named is not the eternal name. 1972 2:0a 1973 ====1 1974 1:4c 1975 The Named is the mother of all things. 1976 2:2,3c 1977 3:4,5c 1978 The named is the mother of all things. 1979 1980 ====3 1981 1:8c 1982 2:7c 1983 so we may see their outcome. 1984 3:9c 1985 so we may see their result. 1986 ==== 1987 1:11a 1988 2:11,13c 1989 They both may be called deep and profound. 1990 Deeper and more profound, 1991 The door of all subtleties! 1992 3:13,14c 1993 1994 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 1995 1996 1997File: diffutils.info, Node: Detailed diff3 Normal, Next: diff3 Hunks, Prev: Example diff3 Normal, Up: Comparing Three Files 1998 19997.3 Detailed Description of 'diff3' Normal Format 2000================================================= 2001 2002Each hunk begins with a line marked '===='. Three-way hunks have plain 2003'====' lines, and two-way hunks have '1', '2', or '3' appended to 2004specify which of the three input files differ in that hunk. The hunks 2005contain copies of two or three sets of input lines each preceded by one 2006or two commands identifying where the lines came from. 2007 2008 Normally, two spaces precede each copy of an input line to 2009distinguish it from the commands. But with the '--initial-tab' ('-T') 2010option, 'diff3' uses a tab instead of two spaces; this lines up tabs 2011correctly. *Note Tabs::, for more information. 2012 2013 Commands take the following forms: 2014 2015'FILE:La' 2016 This hunk appears after line L of file FILE, and contains no lines 2017 in that file. To edit this file to yield the other files, one must 2018 append hunk lines taken from the other files. For example, '1:11a' 2019 means that the hunk follows line 11 in the first file and contains 2020 no lines from that file. 2021 2022'FILE:Rc' 2023 This hunk contains the lines in the range R of file FILE. The 2024 range R is a comma-separated pair of line numbers, or just one 2025 number if there is only one line. To edit this file to yield the 2026 other files, one must change the specified lines to be the lines 2027 taken from the other files. For example, '2:11,13c' means that the 2028 hunk contains lines 11 through 13 from the second file. 2029 2030 If the last line in a set of input lines is incomplete (*note 2031Incomplete Lines::), it is distinguished on output from a full line by a 2032following line that starts with '\'. 2033 2034 2035File: diffutils.info, Node: diff3 Hunks, Prev: Detailed diff3 Normal, Up: Comparing Three Files 2036 20377.4 'diff3' Hunks 2038================= 2039 2040Groups of lines that differ in two or three of the input files are 2041called "diff3 hunks", by analogy with 'diff' hunks (*note Hunks::). If 2042all three input files differ in a 'diff3' hunk, the hunk is called a 2043"three-way hunk"; if just two input files differ, it is a "two-way 2044hunk". 2045 2046 As with 'diff', several solutions are possible. When comparing the 2047files 'A', 'B', and 'C', 'diff3' normally finds 'diff3' hunks by merging 2048the two-way hunks output by the two commands 'diff A B' and 'diff A C'. 2049This does not necessarily minimize the size of the output, but 2050exceptions should be rare. 2051 2052 For example, suppose 'F' contains the three lines 'a', 'b', 'f', 'G' 2053contains the lines 'g', 'b', 'g', and 'H' contains the lines 'a', 'b', 2054'h'. 'diff3 F G H' might output the following: 2055 2056 ====2 2057 1:1c 2058 3:1c 2059 a 2060 2:1c 2061 g 2062 ==== 2063 1:3c 2064 f 2065 2:3c 2066 g 2067 3:3c 2068 h 2069 2070because it found a two-way hunk containing 'a' in the first and third 2071files and 'g' in the second file, then the single line 'b' common to all 2072three files, then a three-way hunk containing the last line of each 2073file. 2074 2075 2076File: diffutils.info, Node: diff3 Merging, Next: Interactive Merging, Prev: Comparing Three Files, Up: Top 2077 20788 Merging From a Common Ancestor 2079******************************** 2080 2081When two people have made changes to copies of the same file, 'diff3' 2082can produce a merged output that contains both sets of changes together 2083with warnings about conflicts. 2084 2085 One might imagine programs with names like 'diff4' and 'diff5' to 2086compare more than three files simultaneously, but in practice the need 2087rarely arises. You can use 'diff3' to merge three or more sets of 2088changes to a file by merging two change sets at a time. 2089 2090 'diff3' can incorporate changes from two modified versions into a 2091common preceding version. This lets you merge the sets of changes 2092represented by the two newer files. Specify the common ancestor version 2093as the second argument and the two newer versions as the first and third 2094arguments, like this: 2095 2096 diff3 MINE OLDER YOURS 2097 2098You can remember the order of the arguments by noting that they are in 2099alphabetical order. 2100 2101 You can think of this as subtracting OLDER from YOURS and adding the 2102result to MINE, or as merging into MINE the changes that would turn 2103OLDER into YOURS. This merging is well-defined as long as MINE and 2104OLDER match in the neighborhood of each such change. This fails to be 2105true when all three input files differ or when only OLDER differs; we 2106call this a "conflict". When all three input files differ, we call the 2107conflict an "overlap". 2108 2109 'diff3' gives you several ways to handle overlaps and conflicts. You 2110can omit overlaps or conflicts, or select only overlaps, or mark 2111conflicts with special '<<<<<<<' and '>>>>>>>' lines. 2112 2113 'diff3' can output the merge results as an 'ed' script that that can 2114be applied to the first file to yield the merged output. However, it is 2115usually better to have 'diff3' generate the merged output directly; this 2116bypasses some problems with 'ed'. 2117 2118* Menu: 2119 2120* Which Changes:: Selecting changes to incorporate. 2121* Marking Conflicts:: Marking conflicts. 2122* Bypassing ed:: Generating merged output directly. 2123* Merging Incomplete Lines:: How 'diff3' merges incomplete lines. 2124* Saving the Changed File:: Emulating System V behavior. 2125 2126 2127File: diffutils.info, Node: Which Changes, Next: Marking Conflicts, Up: diff3 Merging 2128 21298.1 Selecting Which Changes to Incorporate 2130========================================== 2131 2132You can select all unmerged changes from OLDER to YOURS for merging into 2133MINE with the '--ed' ('-e') option. You can select only the 2134nonoverlapping unmerged changes with '--easy-only' ('-3'), and you can 2135select only the overlapping changes with '--overlap-only' ('-x'). 2136 2137 The '-e', '-3' and '-x' options select only "unmerged changes", i.e. 2138changes where MINE and YOURS differ; they ignore changes from OLDER to 2139YOURS where MINE and YOURS are identical, because they assume that such 2140changes have already been merged. If this assumption is not a safe one, 2141you can use the '--show-all' ('-A') option (*note Marking Conflicts::). 2142 2143 Here is the output of the command 'diff3' with each of these three 2144options (*note Sample diff3 Input::, for the complete contents of the 2145files). Notice that '-e' outputs the union of the disjoint sets of 2146changes output by '-3' and '-x'. 2147 2148 Output of 'diff3 -e lao tzu tao': 2149 11a 2150 2151 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 2152 . 2153 8c 2154 so we may see their result. 2155 . 2156 2157 Output of 'diff3 -3 lao tzu tao': 2158 8c 2159 so we may see their result. 2160 . 2161 2162 Output of 'diff3 -x lao tzu tao': 2163 11a 2164 2165 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 2166 . 2167 2168 2169File: diffutils.info, Node: Marking Conflicts, Next: Bypassing ed, Prev: Which Changes, Up: diff3 Merging 2170 21718.2 Marking Conflicts 2172===================== 2173 2174'diff3' can mark conflicts in the merged output by bracketing them with 2175special marker lines. A conflict that comes from two files A and B is 2176marked as follows: 2177 2178 <<<<<<< A 2179 lines from A 2180 ======= 2181 lines from B 2182 >>>>>>> B 2183 2184 A conflict that comes from three files A, B and C is marked as 2185follows: 2186 2187 <<<<<<< A 2188 lines from A 2189 ||||||| B 2190 lines from B 2191 ======= 2192 lines from C 2193 >>>>>>> C 2194 2195 The '--show-all' ('-A') option acts like the '-e' option, except that 2196it brackets conflicts, and it outputs all changes from OLDER to YOURS, 2197not just the unmerged changes. Thus, given the sample input files 2198(*note Sample diff3 Input::), 'diff3 -A lao tzu tao' puts brackets 2199around the conflict where only 'tzu' differs: 2200 2201 <<<<<<< tzu 2202 ======= 2203 The Way that can be told of is not the eternal Way; 2204 The name that can be named is not the eternal name. 2205 >>>>>>> tao 2206 2207 And it outputs the three-way conflict as follows: 2208 2209 <<<<<<< lao 2210 ||||||| tzu 2211 They both may be called deep and profound. 2212 Deeper and more profound, 2213 The door of all subtleties! 2214 ======= 2215 2216 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 2217 >>>>>>> tao 2218 2219 The '--show-overlap' ('-E') option outputs less information than the 2220'--show-all' ('-A') option, because it outputs only unmerged changes, 2221and it never outputs the contents of the second file. Thus the '-E' 2222option acts like the '-e' option, except that it brackets the first and 2223third files from three-way overlapping changes. Similarly, '-X' acts 2224like '-x', except it brackets all its (necessarily overlapping) changes. 2225For example, for the three-way overlapping change above, the '-E' and 2226'-X' options output the following: 2227 2228 <<<<<<< lao 2229 ======= 2230 2231 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 2232 >>>>>>> tao 2233 2234 If you are comparing files that have meaningless or uninformative 2235names, you can use the '--label=LABEL' option to show alternate names in 2236the '<<<<<<<', '|||||||' and '>>>>>>>' brackets. This option can be 2237given up to three times, once for each input file. Thus 'diff3 -A 2238--label X --label Y --label Z A B C' acts like 'diff3 -A A B C', except 2239that the output looks like it came from files named 'X', 'Y' and 'Z' 2240rather than from files named 'A', 'B' and 'C'. 2241 2242 2243File: diffutils.info, Node: Bypassing ed, Next: Merging Incomplete Lines, Prev: Marking Conflicts, Up: diff3 Merging 2244 22458.3 Generating the Merged Output Directly 2246========================================= 2247 2248With the '--merge' ('-m') option, 'diff3' outputs the merged file 2249directly. This is more efficient than using 'ed' to generate it, and 2250works even with non-text files that 'ed' would reject. If you specify 2251'-m' without an 'ed' script option, '-A' is assumed. 2252 2253 For example, the command 'diff3 -m lao tzu tao' (*note Sample diff3 2254Input:: for a copy of the input files) would output the following: 2255 2256 <<<<<<< tzu 2257 ======= 2258 The Way that can be told of is not the eternal Way; 2259 The name that can be named is not the eternal name. 2260 >>>>>>> tao 2261 The Nameless is the origin of Heaven and Earth; 2262 The Named is the mother of all things. 2263 Therefore let there always be non-being, 2264 so we may see their subtlety, 2265 And let there always be being, 2266 so we may see their result. 2267 The two are the same, 2268 But after they are produced, 2269 they have different names. 2270 <<<<<<< lao 2271 ||||||| tzu 2272 They both may be called deep and profound. 2273 Deeper and more profound, 2274 The door of all subtleties! 2275 ======= 2276 2277 -- The Way of Lao-Tzu, tr. Wing-tsit Chan 2278 >>>>>>> tao 2279 2280 2281File: diffutils.info, Node: Merging Incomplete Lines, Next: Saving the Changed File, Prev: Bypassing ed, Up: diff3 Merging 2282 22838.4 How 'diff3' Merges Incomplete Lines 2284======================================= 2285 2286With '-m', incomplete lines (*note Incomplete Lines::) are simply copied 2287to the output as they are found; if the merged output ends in an 2288conflict and one of the input files ends in an incomplete line, 2289succeeding '|||||||', '=======' or '>>>>>>>' brackets appear somewhere 2290other than the start of a line because they are appended to the 2291incomplete line. 2292 2293 Without '-m', if an 'ed' script option is specified and an incomplete 2294line is found, 'diff3' generates a warning and acts as if a newline had 2295been present. 2296 2297 2298File: diffutils.info, Node: Saving the Changed File, Prev: Merging Incomplete Lines, Up: diff3 Merging 2299 23008.5 Saving the Changed File 2301=========================== 2302 2303Traditional Unix 'diff3' generates an 'ed' script without the trailing 2304'w' and 'q' commands that save the changes. System V 'diff3' generates 2305these extra commands. GNU 'diff3' normally behaves like traditional 2306Unix 'diff3', but with the '-i' option it behaves like System V 'diff3' 2307and appends the 'w' and 'q' commands. 2308 2309 The '-i' option requires one of the 'ed' script options '-AeExX3', 2310and is incompatible with the merged output option '-m'. 2311 2312 2313File: diffutils.info, Node: Interactive Merging, Next: Merging with patch, Prev: diff3 Merging, Up: Top 2314 23159 Interactive Merging with 'sdiff' 2316********************************** 2317 2318With 'sdiff', you can merge two files interactively based on a 2319side-by-side '-y' format comparison (*note Side by Side::). Use 2320'--output=FILE' ('-o FILE') to specify where to put the merged text. 2321*Note Invoking sdiff::, for more details on the options to 'sdiff'. 2322 2323 Another way to merge files interactively is to use the Emacs Lisp 2324package 'emerge'. *Note Emerge: (emacs)Emerge, for more information. 2325 2326* Menu: 2327 2328* sdiff Option Summary:: Summary of 'sdiff' options. 2329* Merge Commands:: Merging two files interactively. 2330 2331 2332File: diffutils.info, Node: sdiff Option Summary, Next: Merge Commands, Up: Interactive Merging 2333 23349.1 Specifying 'diff' Options to 'sdiff' 2335======================================== 2336 2337The following 'sdiff' options have the same meaning as for 'diff'. 2338*Note diff Options::, for the use of these options. 2339 2340 -a -b -d -i -t -v 2341 -B -E -I REGEXP -Z 2342 2343 --expand-tabs 2344 --ignore-blank-lines --ignore-case 2345 --ignore-matching-lines=REGEXP --ignore-space-change 2346 --ignore-tab-expansion --ignore-trailing-space 2347 --left-column --minimal --speed-large-files 2348 --strip-trailing-cr --suppress-common-lines 2349 --tabsize=COLUMNS --text --version --width=COLUMNS 2350 2351 For historical reasons, 'sdiff' has alternate names for some options. 2352The '-l' option is equivalent to the '--left-column' option, and 2353similarly '-s' is equivalent to '--suppress-common-lines'. The meaning 2354of the 'sdiff' '-w' and '-W' options is interchanged from that of 2355'diff': with 'sdiff', '-w COLUMNS' is equivalent to '--width=COLUMNS', 2356and '-W' is equivalent to '--ignore-all-space'. 'sdiff' without the 2357'-o' option is equivalent to 'diff' with the '--side-by-side' ('-y') 2358option (*note Side by Side::). 2359 2360 2361File: diffutils.info, Node: Merge Commands, Prev: sdiff Option Summary, Up: Interactive Merging 2362 23639.2 Merge Commands 2364================== 2365 2366Groups of common lines, with a blank gutter, are copied from the first 2367file to the output. After each group of differing lines, 'sdiff' 2368prompts with '%' and pauses, waiting for one of the following commands. 2369Follow each command with <RET>. 2370 2371'e' 2372 Discard both versions. Invoke a text editor on an empty temporary 2373 file, then copy the resulting file to the output. 2374 2375'eb' 2376 Concatenate the two versions, edit the result in a temporary file, 2377 then copy the edited result to the output. 2378 2379'ed' 2380 Like 'eb', except precede each version with a header that shows 2381 what file and lines the version came from. 2382 2383'el' 2384'e1' 2385 Edit a copy of the left version, then copy the result to the 2386 output. 2387 2388'er' 2389'e2' 2390 Edit a copy of the right version, then copy the result to the 2391 output. 2392 2393'l' 2394'1' 2395 Copy the left version to the output. 2396 2397'q' 2398 Quit. 2399 2400'r' 2401'2' 2402 Copy the right version to the output. 2403 2404's' 2405 Silently copy common lines. 2406 2407'v' 2408 Verbosely copy common lines. This is the default. 2409 2410 The text editor invoked is specified by the 'EDITOR' environment 2411variable if it is set. The default is system-dependent. 2412 2413 2414File: diffutils.info, Node: Merging with patch, Next: Making Patches, Prev: Interactive Merging, Up: Top 2415 241610 Merging with 'patch' 2417*********************** 2418 2419'patch' takes comparison output produced by 'diff' and applies the 2420differences to a copy of the original file, producing a patched version. 2421With 'patch', you can distribute just the changes to a set of files 2422instead of distributing the entire file set; your correspondents can 2423apply 'patch' to update their copy of the files with your changes. 2424'patch' automatically determines the diff format, skips any leading or 2425trailing headers, and uses the headers to determine which file to patch. 2426This lets your correspondents feed a mail message containing a 2427difference listing directly to 'patch'. 2428 2429 'patch' detects and warns about common problems like forward patches. 2430It saves any patches that it could not apply. It can also maintain a 2431'patchlevel.h' file to ensure that your correspondents apply diffs in 2432the proper order. 2433 2434 'patch' accepts a series of diffs in its standard input, usually 2435separated by headers that specify which file to patch. It applies 2436'diff' hunks (*note Hunks::) one by one. If a hunk does not exactly 2437match the original file, 'patch' uses heuristics to try to patch the 2438file as well as it can. If no approximate match can be found, 'patch' 2439rejects the hunk and skips to the next hunk. 'patch' normally replaces 2440each file F with its new version, putting reject hunks (if any) into 2441'F.rej'. 2442 2443 *Note Invoking patch::, for detailed information on the options to 2444'patch'. 2445 2446* Menu: 2447 2448* patch Input:: Selecting the type of 'patch' input. 2449* Revision Control:: Getting files from RCS, SCCS, etc. 2450* Imperfect:: Dealing with imperfect patches. 2451* Creating and Removing:: Creating and removing files with a patch. 2452* Patching Timestamps:: Updating timestamps on patched files. 2453* Multiple Patches:: Handling multiple patches in a file. 2454* patch Directories:: Changing directory and stripping directories. 2455* Backups:: Whether backup files are made. 2456* Backup Names:: Backup file names. 2457* Reject Names:: Reject file names. 2458* patch Messages:: Messages and questions 'patch' can produce. 2459* patch and POSIX:: Conformance to the POSIX standard. 2460* patch and Tradition:: GNU versus traditional 'patch'. 2461 2462 2463File: diffutils.info, Node: patch Input, Next: Revision Control, Up: Merging with patch 2464 246510.1 Selecting the 'patch' Input Format 2466======================================= 2467 2468'patch' normally determines which 'diff' format the patch file uses by 2469examining its contents. For patch files that contain particularly 2470confusing leading text, you might need to use one of the following 2471options to force 'patch' to interpret the patch file as a certain format 2472of diff. The output formats listed here are the only ones that 'patch' 2473can understand. 2474 2475'-c' 2476'--context' 2477 context diff. 2478 2479'-e' 2480'--ed' 2481 'ed' script. 2482 2483'-n' 2484'--normal' 2485 normal diff. 2486 2487'-u' 2488'--unified' 2489 unified diff. 2490 2491 2492File: diffutils.info, Node: Revision Control, Next: Imperfect, Prev: patch Input, Up: Merging with patch 2493 249410.2 Revision Control 2495===================== 2496 2497If a nonexistent input file is under a revision control system supported 2498by 'patch', 'patch' normally asks the user whether to get (or check out) 2499the file from the revision control system. Patch currently supports 2500RCS, ClearCase and SCCS. Under RCS and SCCS, 'patch' also asks when the 2501input file is read-only and matches the default version in the revision 2502control system. 2503 2504 The '--get=NUM' ('-g NUM') option affects access to files under 2505supported revision control systems. If NUM is positive, 'patch' gets 2506the file without asking the user; if zero, 'patch' neither asks the user 2507nor gets the file; and if negative, 'patch' asks the user before getting 2508the file. The default value of NUM is given by the value of the 2509'PATCH_GET' environment variable if it is set; if not, the default value 2510is zero if 'patch' is conforming to POSIX, negative otherwise. *Note 2511patch and POSIX::. 2512 2513 The choice of revision control system is unaffected by the 2514'VERSION_CONTROL' environment variable (*note Backup Names::). 2515 2516 2517File: diffutils.info, Node: Imperfect, Next: Creating and Removing, Prev: Revision Control, Up: Merging with patch 2518 251910.3 Applying Imperfect Patches 2520=============================== 2521 2522'patch' tries to skip any leading text in the patch file, apply the 2523diff, and then skip any trailing text. Thus you can feed a mail message 2524directly to 'patch', and it should work. If the entire diff is indented 2525by a constant amount of white space, 'patch' automatically ignores the 2526indentation. If a context diff contains trailing carriage return on 2527each line, 'patch' automatically ignores the carriage return. If a 2528context diff has been encapsulated by prepending '- ' to lines beginning 2529with '-' as per Internet RFC 934 2530(ftp://ftp.isi.edu/in-notes/rfc934.txt), 'patch' automatically 2531unencapsulates the input. 2532 2533 However, certain other types of imperfect input require user 2534intervention or testing. 2535 2536* Menu: 2537 2538* Changed White Space:: When tabs and spaces don't match exactly. 2539* Reversed Patches:: Applying reversed patches correctly. 2540* Inexact:: Helping 'patch' find close matches. 2541* Dry Runs:: Predicting what 'patch' will do. 2542 2543 2544File: diffutils.info, Node: Changed White Space, Next: Reversed Patches, Up: Imperfect 2545 254610.3.1 Applying Patches with Changed White Space 2547------------------------------------------------ 2548 2549Sometimes mailers, editors, or other programs change spaces into tabs, 2550or vice versa. If this happens to a patch file or an input file, the 2551files might look the same, but 'patch' will not be able to match them 2552properly. If this problem occurs, use the '-l' or 2553'--ignore-white-space' option, which makes 'patch' compare blank 2554characters (i.e. spaces and tabs) loosely so that any nonempty sequence 2555of blanks in the patch file matches any nonempty sequence of blanks in 2556the input files. Non-blank characters must still match exactly. Each 2557line of the context must still match a line in the input file. 2558 2559 2560File: diffutils.info, Node: Reversed Patches, Next: Inexact, Prev: Changed White Space, Up: Imperfect 2561 256210.3.2 Applying Reversed Patches 2563-------------------------------- 2564 2565Sometimes people run 'diff' with the new file first instead of second. 2566This creates a diff that is "reversed". To apply such patches, give 2567'patch' the '--reverse' ('-R') option. 'patch' then attempts to swap 2568each hunk around before applying it. Rejects come out in the swapped 2569format. 2570 2571 Often 'patch' can guess that the patch is reversed. If the first 2572hunk of a patch fails, 'patch' reverses the hunk to see if it can apply 2573it that way. If it can, 'patch' asks you if you want to have the '-R' 2574option set; if it can't, 'patch' continues to apply the patch normally. 2575This method cannot detect a reversed patch if it is a normal diff and 2576the first command is an append (which should have been a delete) since 2577appends always succeed, because a null context matches anywhere. But 2578most patches add or change lines rather than delete them, so most 2579reversed normal diffs begin with a delete, which fails, and 'patch' 2580notices. 2581 2582 If you apply a patch that you have already applied, 'patch' thinks it 2583is a reversed patch and offers to un-apply the patch. This could be 2584construed as a feature. If you did this inadvertently and you don't 2585want to un-apply the patch, just answer 'n' to this offer and to the 2586subsequent "apply anyway" question--or type 'C-c' to kill the 'patch' 2587process. 2588 2589 2590File: diffutils.info, Node: Inexact, Next: Dry Runs, Prev: Reversed Patches, Up: Imperfect 2591 259210.3.3 Helping 'patch' Find Inexact Matches 2593------------------------------------------- 2594 2595For context diffs, and to a lesser extent normal diffs, 'patch' can 2596detect when the line numbers mentioned in the patch are incorrect, and 2597it attempts to find the correct place to apply each hunk of the patch. 2598As a first guess, it takes the line number mentioned in the hunk, plus 2599or minus any offset used in applying the previous hunk. If that is not 2600the correct place, 'patch' scans both forward and backward for a set of 2601lines matching the context given in the hunk. 2602 2603 First 'patch' looks for a place where all lines of the context match. 2604If it cannot find such a place, and it is reading a context or unified 2605diff, and the maximum fuzz factor is set to 1 or more, then 'patch' 2606makes another scan, ignoring the first and last line of context. If 2607that fails, and the maximum fuzz factor is set to 2 or more, it makes 2608another scan, ignoring the first two and last two lines of context are 2609ignored. It continues similarly if the maximum fuzz factor is larger. 2610 2611 The '--fuzz=LINES' ('-F LINES') option sets the maximum fuzz factor 2612to LINES. This option only applies to context and unified diffs; it 2613ignores up to LINES lines while looking for the place to install a hunk. 2614Note that a larger fuzz factor increases the odds of making a faulty 2615patch. The default fuzz factor is 2; there is no point to setting it to 2616more than the number of lines of context in the diff, ordinarily 3. 2617 2618 If 'patch' cannot find a place to install a hunk of the patch, it 2619writes the hunk out to a reject file (*note Reject Names::, for 2620information on how reject files are named). It writes out rejected 2621hunks in context format no matter what form the input patch is in. If 2622the input is a normal or 'ed' diff, many of the contexts are simply 2623null. The line numbers on the hunks in the reject file may be different 2624from those in the patch file: they show the approximate location where 2625'patch' thinks the failed hunks belong in the new file rather than in 2626the old one. 2627 2628 If the '--verbose' option is given, then as it completes each hunk 2629'patch' tells you whether the hunk succeeded or failed, and if it 2630failed, on which line (in the new file) 'patch' thinks the hunk should 2631go. If this is different from the line number specified in the diff, it 2632tells you the offset. A single large offset _may_ indicate that 'patch' 2633installed a hunk in the wrong place. 'patch' also tells you if it used 2634a fuzz factor to make the match, in which case you should also be 2635slightly suspicious. 2636 2637 'patch' cannot tell if the line numbers are off in an 'ed' script, 2638and can only detect wrong line numbers in a normal diff when it finds a 2639change or delete command. It may have the same problem with a context 2640diff using a fuzz factor equal to or greater than the number of lines of 2641context shown in the diff (typically 3). In these cases, you should 2642probably look at a context diff between your original and patched input 2643files to see if the changes make sense. Compiling without errors is a 2644pretty good indication that the patch worked, but not a guarantee. 2645 2646 A patch against an empty file applies to a nonexistent file, and vice 2647versa. *Note Creating and Removing::. 2648 2649 'patch' usually produces the correct results, even when it must make 2650many guesses. However, the results are guaranteed only when the patch 2651is applied to an exact copy of the file that the patch was generated 2652from. 2653 2654 2655File: diffutils.info, Node: Dry Runs, Prev: Inexact, Up: Imperfect 2656 265710.3.4 Predicting what 'patch' will do 2658-------------------------------------- 2659 2660It may not be obvious in advance what 'patch' will do with a complicated 2661or poorly formatted patch. If you are concerned that the input might 2662cause 'patch' to modify the wrong files, you can use the '--dry-run' 2663option, which causes 'patch' to print the results of applying patches 2664without actually changing any files. You can then inspect the 2665diagnostics generated by the dry run to see whether 'patch' will modify 2666the files that you expect. If the patch does not do what you want, you 2667can modify the patch (or the other options to 'patch') and try another 2668dry run. Once you are satisfied with the proposed patch you can apply 2669it by invoking 'patch' as before, but this time without the '--dry-run' 2670option. 2671 2672 2673File: diffutils.info, Node: Creating and Removing, Next: Patching Timestamps, Prev: Imperfect, Up: Merging with patch 2674 267510.4 Creating and Removing Files 2676================================ 2677 2678Sometimes when comparing two directories, a file may exist in one 2679directory but not the other. If you give 'diff' the '--new-file' ('-N') 2680option, or if you supply an old or new file that is named '/dev/null' or 2681is empty and is dated the Epoch (1970-01-01 00:00:00 UTC), 'diff' 2682outputs a patch that adds or deletes the contents of this file. When 2683given such a patch, 'patch' normally creates a new file or removes the 2684old file. However, when conforming to POSIX (*note patch and POSIX::), 2685'patch' does not remove the old file, but leaves it empty. The 2686'--remove-empty-files' ('-E') option causes 'patch' to remove output 2687files that are empty after applying a patch, even if the patch does not 2688appear to be one that removed the file. 2689 2690 If the patch appears to create a file that already exists, 'patch' 2691asks for confirmation before applying the patch. 2692 2693 2694File: diffutils.info, Node: Patching Timestamps, Next: Multiple Patches, Prev: Creating and Removing, Up: Merging with patch 2695 269610.5 Updating Timestamps on Patched Files 2697========================================= 2698 2699When 'patch' updates a file, it normally sets the file's last-modified 2700timestamp to the current time of day. If you are using 'patch' to track 2701a software distribution, this can cause 'make' to incorrectly conclude 2702that a patched file is out of date. For example, if 'syntax.c' depends 2703on 'syntax.y', and 'patch' updates 'syntax.c' and then 'syntax.y', then 2704'syntax.c' will normally appear to be out of date with respect to 2705'syntax.y' even though its contents are actually up to date. 2706 2707 The '--set-utc' ('-Z') option causes 'patch' to set a patched file's 2708modification and access times to the timestamps given in context diff 2709headers. If the context diff headers do not specify a time zone, they 2710are assumed to use Coordinated Universal Time (UTC, often known as GMT). 2711 2712 The '--set-time' ('-T') option acts like '-Z' or '--set-utc', except 2713that it assumes that the context diff headers' timestamps use local time 2714instead of UTC. This option is not recommended, because patches using 2715local time cannot easily be used by people in other time zones, and 2716because local timestamps are ambiguous when local clocks move backwards 2717during daylight-saving time adjustments. If the context diff headers 2718specify a time zone, this option is equivalent to '--set-utc' ('-Z'). 2719 2720 'patch' normally refrains from setting a file's timestamps if the 2721file's original last-modified timestamp does not match the time given in 2722the diff header, of if the file's contents do not exactly match the 2723patch. However, if the '--force' ('-f') option is given, the file's 2724timestamps are set regardless. 2725 2726 Due to the limitations of the current 'diff' format, 'patch' cannot 2727update the times of files whose contents have not changed. Also, if you 2728set file timestamps to values other than the current time of day, you 2729should also remove (e.g., with 'make clean') all files that depend on 2730the patched files, so that later invocations of 'make' do not get 2731confused by the patched files' times. 2732 2733 2734File: diffutils.info, Node: Multiple Patches, Next: patch Directories, Prev: Patching Timestamps, Up: Merging with patch 2735 273610.6 Multiple Patches in a File 2737=============================== 2738 2739If the patch file contains more than one patch, and if you do not 2740specify an input file on the command line, 'patch' tries to apply each 2741patch as if they came from separate patch files. This means that it 2742determines the name of the file to patch for each patch, and that it 2743examines the leading text before each patch for file names and 2744prerequisite revision level (*note Making Patches::, for more on that 2745topic). 2746 2747 'patch' uses the following rules to intuit a file name from the 2748leading text before a patch. First, 'patch' takes an ordered list of 2749candidate file names as follows: 2750 2751 * If the header is that of a context diff, 'patch' takes the old and 2752 new file names in the header. A name is ignored if it does not 2753 have enough slashes to satisfy the '-pNUM' or '--strip=NUM' option. 2754 The name '/dev/null' is also ignored. 2755 2756 * If there is an 'Index:' line in the leading garbage and if either 2757 the old and new names are both absent or if 'patch' is conforming 2758 to POSIX, 'patch' takes the name in the 'Index:' line. 2759 2760 * For the purpose of the following rules, the candidate file names 2761 are considered to be in the order (old, new, index), regardless of 2762 the order that they appear in the header. 2763 2764Then 'patch' selects a file name from the candidate list as follows: 2765 2766 * If some of the named files exist, 'patch' selects the first name if 2767 conforming to POSIX, and the best name otherwise. 2768 2769 * If 'patch' is not ignoring RCS, ClearCase, and SCCS (*note Revision 2770 Control::), and no named files exist but an RCS, ClearCase, or SCCS 2771 master is found, 'patch' selects the first named file with an RCS, 2772 ClearCase, or SCCS master. 2773 2774 * If no named files exist, no RCS, ClearCase, or SCCS master was 2775 found, some names are given, 'patch' is not conforming to POSIX, 2776 and the patch appears to create a file, 'patch' selects the best 2777 name requiring the creation of the fewest directories. 2778 2779 * If no file name results from the above heuristics, you are asked 2780 for the name of the file to patch, and 'patch' selects that name. 2781 2782 To determine the "best" of a nonempty list of file names, 'patch' 2783first takes all the names with the fewest path name components; of 2784those, it then takes all the names with the shortest basename; of those, 2785it then takes all the shortest names; finally, it takes the first 2786remaining name. 2787 2788 *Note patch and POSIX::, to see whether 'patch' is conforming to 2789POSIX. 2790 2791 2792File: diffutils.info, Node: patch Directories, Next: Backups, Prev: Multiple Patches, Up: Merging with patch 2793 279410.7 Applying Patches in Other Directories 2795========================================== 2796 2797The '--directory=DIRECTORY' ('-d DIRECTORY') option to 'patch' makes 2798directory DIRECTORY the current directory for interpreting both file 2799names in the patch file, and file names given as arguments to other 2800options (such as '-B' and '-o'). For example, while in a mail reading 2801program, you can patch a file in the '/usr/src/emacs' directory directly 2802from a message containing the patch like this: 2803 2804 | patch -d /usr/src/emacs 2805 2806 Sometimes the file names given in a patch contain leading 2807directories, but you keep your files in a directory different from the 2808one given in the patch. In those cases, you can use the 2809'--strip=NUMBER' ('-pNUMBER') option to set the file name strip count to 2810NUMBER. The strip count tells 'patch' how many slashes, along with the 2811directory names between them, to strip from the front of file names. A 2812sequence of one or more adjacent slashes is counted as a single slash. 2813By default, 'patch' strips off all leading directories, leaving just the 2814base file names. 2815 2816 For example, suppose the file name in the patch file is 2817'/gnu/src/emacs/etc/NEWS'. Using '-p0' gives the entire file name 2818unmodified, '-p1' gives 'gnu/src/emacs/etc/NEWS' (no leading slash), 2819'-p4' gives 'etc/NEWS', and not specifying '-p' at all gives 'NEWS'. 2820 2821 'patch' looks for each file (after any slashes have been stripped) in 2822the current directory, or if you used the '-d DIRECTORY' option, in that 2823directory. 2824 2825 2826File: diffutils.info, Node: Backups, Next: Backup Names, Prev: patch Directories, Up: Merging with patch 2827 282810.8 Backup Files 2829================= 2830 2831Normally, 'patch' creates a backup file if the patch does not exactly 2832match the original input file, because in that case the original data 2833might not be recovered if you undo the patch with 'patch -R' (*note 2834Reversed Patches::). However, when conforming to POSIX, 'patch' does 2835not create backup files by default. *Note patch and POSIX::. 2836 2837 The '--backup' ('-b') option causes 'patch' to make a backup file 2838regardless of whether the patch matches the original input. The 2839'--backup-if-mismatch' option causes 'patch' to create backup files for 2840mismatches files; this is the default when not conforming to POSIX. The 2841'--no-backup-if-mismatch' option causes 'patch' to not create backup 2842files, even for mismatched patches; this is the default when conforming 2843to POSIX. 2844 2845 When backing up a file that does not exist, an empty, unreadable 2846backup file is created as a placeholder to represent the nonexistent 2847file. 2848 2849 2850File: diffutils.info, Node: Backup Names, Next: Reject Names, Prev: Backups, Up: Merging with patch 2851 285210.9 Backup File Names 2853====================== 2854 2855Normally, 'patch' renames an original input file into a backup file by 2856appending to its name the extension '.orig', or '~' if using '.orig' 2857would make the backup file name too long.(1) The '-z BACKUP-SUFFIX' or 2858'--suffix=BACKUP-SUFFIX' option causes 'patch' to use BACKUP-SUFFIX as 2859the backup extension instead. 2860 2861 Alternately, you can specify the extension for backup files with the 2862'SIMPLE_BACKUP_SUFFIX' environment variable, which the options override. 2863 2864 'patch' can also create numbered backup files the way GNU Emacs does. 2865With this method, instead of having a single backup of each file, 2866'patch' makes a new backup file name each time it patches a file. For 2867example, the backups of a file named 'sink' would be called, 2868successively, 'sink.~1~', 'sink.~2~', 'sink.~3~', etc. 2869 2870 The '-V BACKUP-STYLE' or '--version-control=BACKUP-STYLE' option 2871takes as an argument a method for creating backup file names. You can 2872alternately control the type of backups that 'patch' makes with the 2873'PATCH_VERSION_CONTROL' environment variable, which the '-V' option 2874overrides. If 'PATCH_VERSION_CONTROL' is not set, the 'VERSION_CONTROL' 2875environment variable is used instead. Please note that these options 2876and variables control backup file names; they do not affect the choice 2877of revision control system (*note Revision Control::). 2878 2879 The values of these environment variables and the argument to the 2880'-V' option are like the GNU Emacs 'version-control' variable (*note 2881(emacs)Backup Names::, for more information on backup versions in 2882Emacs). They also recognize synonyms that are more descriptive. The 2883valid values are listed below; unique abbreviations are acceptable. 2884 2885't' 2886'numbered' 2887 Always make numbered backups. 2888 2889'nil' 2890'existing' 2891 Make numbered backups of files that already have them, simple 2892 backups of the others. This is the default. 2893 2894'never' 2895'simple' 2896 Always make simple backups. 2897 2898 You can also tell 'patch' to prepend a prefix, such as a directory 2899name, to produce backup file names. The '--prefix=PREFIX' ('-B PREFIX') 2900option makes backup files by prepending PREFIX to them. The 2901'--basename-prefix=PREFIX' ('-Y PREFIX') prepends PREFIX to the last 2902file name component of backup file names instead; for example, '-Y ~' 2903causes the backup name for 'dir/file.c' to be 'dir/~file.c'. If you use 2904either of these prefix options, the suffix-based options are ignored. 2905 2906 If you specify the output file with the '-o' option, that file is the 2907one that is backed up, not the input file. 2908 2909 Options that affect the names of backup files do not affect whether 2910backups are made. For example, if you specify the 2911'--no-backup-if-mismatch' option, none of the options described in this 2912section have any affect, because no backups are made. 2913 2914 ---------- Footnotes ---------- 2915 2916 (1) A coding error in GNU 'patch' version 2.5.4 causes it to always 2917use '~', but this should be fixed in the next release. 2918 2919 2920File: diffutils.info, Node: Reject Names, Next: patch Messages, Prev: Backup Names, Up: Merging with patch 2921 292210.10 Reject File Names 2923======================= 2924 2925The names for reject files (files containing patches that 'patch' could 2926not find a place to apply) are normally the name of the output file with 2927'.rej' appended (or '#' if using '.rej' would make the backup file name 2928too long). 2929 2930 Alternatively, you can tell 'patch' to place all of the rejected 2931patches in a single file. The '-r REJECT-FILE' or 2932'--reject-file=REJECT-FILE' option uses REJECT-FILE as the reject file 2933name. 2934 2935 2936File: diffutils.info, Node: patch Messages, Next: patch and POSIX, Prev: Reject Names, Up: Merging with patch 2937 293810.11 Messages and Questions from 'patch' 2939========================================= 2940 2941'patch' can produce a variety of messages, especially if it has trouble 2942decoding its input. In a few situations where it's not sure how to 2943proceed, 'patch' normally prompts you for more information from the 2944keyboard. There are options to produce more or fewer messages, to have 2945it not ask for keyboard input, and to affect the way that file names are 2946quoted in messages. 2947 2948* Menu: 2949 2950* More or Fewer Messages:: Controlling the verbosity of 'patch'. 2951* patch and Keyboard Input:: Inhibiting keyboard input. 2952* patch Quoting Style:: Quoting file names in diagnostics. 2953 2954 'patch' exits with status 0 if all hunks are applied successfully, 1 2955if some hunks cannot be applied, and 2 if there is more serious trouble. 2956When applying a set of patches in a loop, you should check the exit 2957status, so you don't apply a later patch to a partially patched file. 2958 2959 2960File: diffutils.info, Node: More or Fewer Messages, Next: patch and Keyboard Input, Up: patch Messages 2961 296210.11.1 Controlling the Verbosity of 'patch' 2963-------------------------------------------- 2964 2965You can cause 'patch' to produce more messages by using the '--verbose' 2966option. For example, when you give this option, the message 'Hmm...' 2967indicates that 'patch' is reading text in the patch file, attempting to 2968determine whether there is a patch in that text, and if so, what kind of 2969patch it is. 2970 2971 You can inhibit all terminal output from 'patch', unless an error 2972occurs, by using the '-s', '--quiet', or '--silent' option. 2973 2974 2975File: diffutils.info, Node: patch and Keyboard Input, Next: patch Quoting Style, Prev: More or Fewer Messages, Up: patch Messages 2976 297710.11.2 Inhibiting Keyboard Input 2978--------------------------------- 2979 2980There are two ways you can prevent 'patch' from asking you any 2981questions. The '--force' ('-f') option assumes that you know what you 2982are doing. It causes 'patch' to do the following: 2983 2984 * Skip patches that do not contain file names in their headers. 2985 2986 * Patch files even though they have the wrong version for the 2987 'Prereq:' line in the patch; 2988 2989 * Assume that patches are not reversed even if they look like they 2990 are. 2991 2992The '--batch' ('-t') option is similar to '-f', in that it suppresses 2993questions, but it makes somewhat different assumptions: 2994 2995 * Skip patches that do not contain file names in their headers (the 2996 same as '-f'). 2997 2998 * Skip patches for which the file has the wrong version for the 2999 'Prereq:' line in the patch; 3000 3001 * Assume that patches are reversed if they look like they are. 3002 3003 3004File: diffutils.info, Node: patch Quoting Style, Prev: patch and Keyboard Input, Up: patch Messages 3005 300610.11.3 'patch' Quoting Style 3007----------------------------- 3008 3009When 'patch' outputs a file name in a diagnostic message, it can format 3010the name in any of several ways. This can be useful to output file 3011names unambiguously, even if they contain punctuation or special 3012characters like newlines. The '--quoting-style=WORD' option controls 3013how names are output. The WORD should be one of the following: 3014 3015'literal' 3016 Output names as-is. 3017'shell' 3018 Quote names for the shell if they contain shell metacharacters or 3019 would cause ambiguous output. 3020'shell-always' 3021 Quote names for the shell, even if they would normally not require 3022 quoting. 3023'c' 3024 Quote names as for a C language string. 3025'escape' 3026 Quote as with 'c' except omit the surrounding double-quote 3027 characters. 3028 3029 You can specify the default value of the '--quoting-style' option 3030with the environment variable 'QUOTING_STYLE'. If that environment 3031variable is not set, the default value is 'shell', but this default may 3032change in a future version of 'patch'. 3033 3034 3035File: diffutils.info, Node: patch and POSIX, Next: patch and Tradition, Prev: patch Messages, Up: Merging with patch 3036 303710.12 'patch' and the POSIX Standard 3038==================================== 3039 3040If you specify the '--posix' option, or set the 'POSIXLY_CORRECT' 3041environment variable, 'patch' conforms more strictly to the POSIX 3042standard, as follows: 3043 3044 * Take the first existing file from the list (old, new, index) when 3045 intuiting file names from diff headers. *Note Multiple Patches::. 3046 3047 * Do not remove files that are removed by a diff. *Note Creating and 3048 Removing::. 3049 3050 * Do not ask whether to get files from RCS, ClearCase, or SCCS. *Note 3051 Revision Control::. 3052 3053 * Require that all options precede the files in the command line. 3054 3055 * Do not backup files, even when there is a mismatch. *Note 3056 Backups::. 3057 3058 3059File: diffutils.info, Node: patch and Tradition, Prev: patch and POSIX, Up: Merging with patch 3060 306110.13 GNU 'patch' and Traditional 'patch' 3062========================================= 3063 3064The current version of GNU 'patch' normally follows the POSIX standard. 3065*Note patch and POSIX::, for the few exceptions to this general rule. 3066 3067 Unfortunately, POSIX redefined the behavior of 'patch' in several 3068important ways. You should be aware of the following differences if you 3069must interoperate with traditional 'patch', or with GNU 'patch' version 30702.1 and earlier. 3071 3072 * In traditional 'patch', the '-p' option's operand was optional, and 3073 a bare '-p' was equivalent to '-p0'. The '-p' option now requires 3074 an operand, and '-p 0' is now equivalent to '-p0'. For maximum 3075 compatibility, use options like '-p0' and '-p1'. 3076 3077 Also, traditional 'patch' simply counted slashes when stripping 3078 path prefixes; 'patch' now counts pathname components. That is, a 3079 sequence of one or more adjacent slashes now counts as a single 3080 slash. For maximum portability, avoid sending patches containing 3081 '//' in file names. 3082 3083 * In traditional 'patch', backups were enabled by default. This 3084 behavior is now enabled with the '--backup' ('-b') option. 3085 3086 Conversely, in POSIX 'patch', backups are never made, even when 3087 there is a mismatch. In GNU 'patch', this behavior is enabled with 3088 the '--no-backup-if-mismatch' option, or by conforming to POSIX. 3089 3090 The '-b SUFFIX' option of traditional 'patch' is equivalent to the 3091 '-b -z SUFFIX' options of GNU 'patch'. 3092 3093 * Traditional 'patch' used a complicated (and incompletely 3094 documented) method to intuit the name of the file to be patched 3095 from the patch header. This method did not conform to POSIX, and 3096 had a few gotchas. Now 'patch' uses a different, equally 3097 complicated (but better documented) method that is optionally 3098 POSIX-conforming; we hope it has fewer gotchas. The two methods 3099 are compatible if the file names in the context diff header and the 3100 'Index:' line are all identical after prefix-stripping. Your patch 3101 is normally compatible if each header's file names all contain the 3102 same number of slashes. 3103 3104 * When traditional 'patch' asked the user a question, it sent the 3105 question to standard error and looked for an answer from the first 3106 file in the following list that was a terminal: standard error, 3107 standard output, '/dev/tty', and standard input. Now 'patch' sends 3108 questions to standard output and gets answers from '/dev/tty'. 3109 Defaults for some answers have been changed so that 'patch' never 3110 goes into an infinite loop when using default answers. 3111 3112 * Traditional 'patch' exited with a status value that counted the 3113 number of bad hunks, or with status 1 if there was real trouble. 3114 Now 'patch' exits with status 1 if some hunks failed, or with 2 if 3115 there was real trouble. 3116 3117 * Limit yourself to the following options when sending instructions 3118 meant to be executed by anyone running GNU 'patch', traditional 3119 'patch', or a 'patch' that conforms to POSIX. Spaces are 3120 significant in the following list, and operands are required. 3121 3122 -c 3123 -d DIR 3124 -D DEFINE 3125 -e 3126 -l 3127 -n 3128 -N 3129 -o OUTFILE 3130 -pNUM 3131 -R 3132 -r REJECTFILE 3133 3134 3135File: diffutils.info, Node: Making Patches, Next: Invoking cmp, Prev: Merging with patch, Up: Top 3136 313711 Tips for Making and Using Patches 3138************************************ 3139 3140Use some common sense when making and using patches. For example, when 3141sending bug fixes to a program's maintainer, send several small patches, 3142one per independent subject, instead of one large, harder-to-digest 3143patch that covers all the subjects. 3144 3145 Here are some other things you should keep in mind if you are going 3146to distribute patches for updating a software package. 3147 3148* Menu: 3149 3150* Tips for Patch Producers:: Advice for making patches. 3151* Tips for Patch Consumers:: Advice for using patches. 3152* Avoiding Common Mistakes:: Avoiding common mistakes when using 'patch'. 3153* Generating Smaller Patches:: How to generate smaller patches. 3154 3155 3156File: diffutils.info, Node: Tips for Patch Producers, Next: Tips for Patch Consumers, Up: Making Patches 3157 315811.1 Tips for Patch Producers 3159============================= 3160 3161To create a patch that changes an older version of a package into a 3162newer version, first make a copy of the older and newer versions in 3163adjacent subdirectories. It is common to do that by unpacking 'tar' 3164archives of the two versions. 3165 3166 To generate the patch, use the command 'diff -Naur OLD NEW' where OLD 3167and NEW identify the old and new directories. The names OLD and NEW 3168should not contain any slashes. The '-N' option lets the patch create 3169and remove files; '-a' lets the patch update non-text files; '-u' 3170generates useful timestamps and enough context; and '-r' lets the patch 3171update subdirectories. Here is an example command, using Bourne shell 3172syntax: 3173 3174 diff -Naur gcc-3.0.3 gcc-3.0.4 3175 3176 Tell your recipients how to apply the patches. This should include 3177which working directory to use, and which 'patch' options to use; the 3178option '-p1' is recommended. Test your procedure by pretending to be a 3179recipient and applying your patches to a copy of the original files. 3180 3181 *Note Avoiding Common Mistakes::, for how to avoid common mistakes 3182when generating a patch. 3183 3184 3185File: diffutils.info, Node: Tips for Patch Consumers, Next: Avoiding Common Mistakes, Prev: Tips for Patch Producers, Up: Making Patches 3186 318711.2 Tips for Patch Consumers 3188============================= 3189 3190A patch producer should tell recipients how to apply the patches, so the 3191first rule of thumb for a patch consumer is to follow the instructions 3192supplied with the patch. 3193 3194 GNU 'diff' can analyze files with arbitrarily long lines and files 3195that end in incomplete lines. However, older versions of 'patch' cannot 3196patch such files. If you are having trouble applying such patches, try 3197upgrading to a recent version of GNU 'patch'. 3198 3199 3200File: diffutils.info, Node: Avoiding Common Mistakes, Next: Generating Smaller Patches, Prev: Tips for Patch Consumers, Up: Making Patches 3201 320211.3 Avoiding Common Mistakes 3203============================= 3204 3205When producing a patch for multiple files, apply 'diff' to directories 3206whose names do not have slashes. This reduces confusion when the patch 3207consumer specifies the '-pNUMBER' option, since this option can have 3208surprising results when the old and new file names have different 3209numbers of slashes. For example, do not send a patch with a header that 3210looks like this: 3211 3212 diff -Naur v2.0.29/prog/README prog/README 3213 --- v2.0.29/prog/README 2002-03-10 23:30:39.942229878 -0800 3214 +++ prog/README 2002-03-17 20:49:32.442260588 -0800 3215 3216because the two file names have different numbers of slashes, and 3217different versions of 'patch' interpret the file names differently. To 3218avoid confusion, send output that looks like this instead: 3219 3220 diff -Naur v2.0.29/prog/README v2.0.30/prog/README 3221 --- v2.0.29/prog/README 2002-03-10 23:30:39.942229878 -0800 3222 +++ v2.0.30/prog/README 2002-03-17 20:49:32.442260588 -0800 3223 3224 Make sure you have specified the file names correctly, either in a 3225context diff header or with an 'Index:' line. Take care to not send out 3226reversed patches, since these make people wonder whether they have 3227already applied the patch. 3228 3229 Avoid sending patches that compare backup file names like 3230'README.orig' or 'README~', since this might confuse 'patch' into 3231patching a backup file instead of the real file. Instead, send patches 3232that compare the same base file names in different directories, e.g. 3233'old/README' and 'new/README'. 3234 3235 To save people from partially applying a patch before other patches 3236that should have gone before it, you can make the first patch in the 3237patch file update a file with a name like 'patchlevel.h' or 'version.c', 3238which contains a patch level or version number. If the input file 3239contains the wrong version number, 'patch' will complain immediately. 3240 3241 An even clearer way to prevent this problem is to put a 'Prereq:' 3242line before the patch. If the leading text in the patch file contains a 3243line that starts with 'Prereq:', 'patch' takes the next word from that 3244line (normally a version number) and checks whether the next input file 3245contains that word, preceded and followed by either white space or a 3246newline. If not, 'patch' prompts you for confirmation before 3247proceeding. This makes it difficult to accidentally apply patches in 3248the wrong order. 3249 3250 3251File: diffutils.info, Node: Generating Smaller Patches, Prev: Avoiding Common Mistakes, Up: Making Patches 3252 325311.4 Generating Smaller Patches 3254=============================== 3255 3256The simplest way to generate a patch is to use 'diff -Naur' (*note Tips 3257for Patch Producers::), but you might be able to reduce the size of the 3258patch by renaming or removing some files before making the patch. If 3259the older version of the package contains any files that the newer 3260version does not, or if any files have been renamed between the two 3261versions, make a list of 'rm' and 'mv' commands for the user to execute 3262in the old version directory before applying the patch. Then run those 3263commands yourself in the scratch directory. 3264 3265 If there are any files that you don't need to include in the patch 3266because they can easily be rebuilt from other files (for example, 'TAGS' 3267and output from 'yacc' and 'makeinfo'), exclude them from the patch by 3268giving 'diff' the '-x PATTERN' option (*note Comparing Directories::). 3269If you want your patch to modify a derived file because your recipients 3270lack tools to build it, make sure that the patch for the derived file 3271follows any patches for files that it depends on, so that the 3272recipients' timestamps will not confuse 'make'. 3273 3274 Now you can create the patch using 'diff -Naur'. Make sure to 3275specify the scratch directory first and the newer directory second. 3276 3277 Add to the top of the patch a note telling the user any 'rm' and 'mv' 3278commands to run before applying the patch. Then you can remove the 3279scratch directory. 3280 3281 You can also shrink the patch size by using fewer lines of context, 3282but bear in mind that 'patch' typically needs at least two lines for 3283proper operation when patches do not exactly match the input files. 3284 3285 3286File: diffutils.info, Node: Invoking cmp, Next: Invoking diff, Prev: Making Patches, Up: Top 3287 328812 Invoking 'cmp' 3289***************** 3290 3291The 'cmp' command compares two files, and if they differ, tells the 3292first byte and line number where they differ or reports that one file is 3293a prefix of the other. Bytes and lines are numbered starting with 1. 3294The arguments of 'cmp' are as follows: 3295 3296 cmp OPTIONS... FROM-FILE [TO-FILE [FROM-SKIP [TO-SKIP]]] 3297 3298 The file name '-' is always the standard input. 'cmp' also uses the 3299standard input if one file name is omitted. The FROM-SKIP and TO-SKIP 3300operands specify how many bytes to ignore at the start of each file; 3301they are equivalent to the '--ignore-initial=FROM-SKIP:TO-SKIP' option. 3302 3303 By default, 'cmp' outputs nothing if the two files have the same 3304contents. If the two files have bytes that differ, 'cmp' reports the 3305location of the first difference to standard output: 3306 3307 FROM-FILE TO-FILE differ: char BYTE-NUMBER, line LINE-NUMBER 3308 3309If one file is a prefix of the other, 'cmp' reports the shorter file's 3310name to standard error, followed by a blank and extra information about 3311the shorter file: 3312 3313 cmp: EOF on SHORTER-FILE EXTRA-INFO 3314 3315 The message formats can differ outside the POSIX locale. POSIX 3316allows but does not require the EOF diagnostic's file name to be 3317followed by a blank and additional information. 3318 3319 An exit status of 0 means no differences were found, 1 means some 3320differences were found, and 2 means trouble. 3321 3322* Menu: 3323 3324* cmp Options:: Summary of options to 'cmp'. 3325 3326 3327File: diffutils.info, Node: cmp Options, Up: Invoking cmp 3328 332912.1 Options to 'cmp' 3330===================== 3331 3332Below is a summary of all of the options that GNU 'cmp' accepts. Most 3333options have two equivalent names, one of which is a single letter 3334preceded by '-', and the other of which is a long name preceded by '--'. 3335Multiple single letter options (unless they take an argument) can be 3336combined into a single command line word: '-bl' is equivalent to '-b 3337-l'. 3338 3339'-b' 3340'--print-bytes' 3341 Print the differing bytes. Display control bytes as a '^' followed 3342 by a letter of the alphabet and precede bytes that have the high 3343 bit set with 'M-' (which stands for "meta"). 3344 3345'--help' 3346 Output a summary of usage and then exit. 3347 3348'-i SKIP' 3349'--ignore-initial=SKIP' 3350 Ignore any differences in the first SKIP bytes of the input files. 3351 Treat files with fewer than SKIP bytes as if they are empty. If 3352 SKIP is of the form 'FROM-SKIP:TO-SKIP', skip the first FROM-SKIP 3353 bytes of the first input file and the first TO-SKIP bytes of the 3354 second. 3355 3356'-l' 3357'--verbose' 3358 Output the (decimal) byte numbers and (octal) values of all 3359 differing bytes, instead of the default standard output. Each 3360 output line contains a differing byte's number relative to the 3361 start of the input, followed by the differing byte values. Byte 3362 numbers start at 1. Also, output the EOF message if one file is 3363 shorter than the other. 3364 3365'-n COUNT' 3366'--bytes=COUNT' 3367 Compare at most COUNT input bytes. 3368 3369'-s' 3370'--quiet' 3371'--silent' 3372 Do not print anything; only return an exit status indicating 3373 whether the files differ. 3374 3375'-v' 3376'--version' 3377 Output version information and then exit. 3378 3379 In the above table, operands that are byte counts are normally 3380decimal, but may be preceded by '0' for octal and '0x' for hexadecimal. 3381 3382 A byte count can be followed by a suffix to specify a multiple of 3383that count; in this case an omitted integer is understood to be 1. A 3384bare size letter, or one followed by 'iB', specifies a multiple using 3385powers of 1024. A size letter followed by 'B' specifies powers of 1000 3386instead. For example, '-n 4M' and '-n 4MiB' are equivalent to '-n 33874194304', whereas '-n 4MB' is equivalent to '-n 4000000'. This notation 3388is upward compatible with the SI prefixes 3389(http://www.bipm.fr/enus/3_SI/si-prefixes.html) for decimal multiples 3390and with the IEC 60027-2 prefixes for binary multiples 3391(http://physics.nist.gov/cuu/Units/binary.html). 3392 3393 The following suffixes are defined. Large sizes like '1Y' may be 3394rejected by your computer due to limitations of its arithmetic. 3395 3396'kB' 3397 kilobyte: 10^3 = 1000. 3398'k' 3399'K' 3400'KiB' 3401 kibibyte: 2^10 = 1024. 'K' is special: the SI prefix is 'k' and 3402 the IEC 60027-2 prefix is 'Ki', but tradition and POSIX use 'k' to 3403 mean 'KiB'. 3404'MB' 3405 megabyte: 10^6 = 1,000,000. 3406'M' 3407'MiB' 3408 mebibyte: 2^20 = 1,048,576. 3409'GB' 3410 gigabyte: 10^9 = 1,000,000,000. 3411'G' 3412'GiB' 3413 gibibyte: 2^30 = 1,073,741,824. 3414'TB' 3415 terabyte: 10^12 = 1,000,000,000,000. 3416'T' 3417'TiB' 3418 tebibyte: 2^40 = 1,099,511,627,776. 3419'PB' 3420 petabyte: 10^15 = 1,000,000,000,000,000. 3421'P' 3422'PiB' 3423 pebibyte: 2^50 = 1,125,899,906,842,624. 3424'EB' 3425 exabyte: 10^18 = 1,000,000,000,000,000,000. 3426'E' 3427'EiB' 3428 exbibyte: 2^60 = 1,152,921,504,606,846,976. 3429'ZB' 3430 zettabyte: 10^21 = 1,000,000,000,000,000,000,000 3431'Z' 3432'ZiB' 3433 2^70 = 1,180,591,620,717,411,303,424. ('Zi' is a GNU extension to 3434 IEC 60027-2.) 3435'YB' 3436 yottabyte: 10^24 = 1,000,000,000,000,000,000,000,000. 3437'Y' 3438'YiB' 3439 2^80 = 1,208,925,819,614,629,174,706,176. ('Yi' is a GNU extension 3440 to IEC 60027-2.) 3441 3442 3443File: diffutils.info, Node: Invoking diff, Next: Invoking diff3, Prev: Invoking cmp, Up: Top 3444 344513 Invoking 'diff' 3446****************** 3447 3448The format for running the 'diff' command is: 3449 3450 diff OPTIONS... FILES... 3451 3452 In the simplest case, two file names FROM-FILE and TO-FILE are given, 3453and 'diff' compares the contents of FROM-FILE and TO-FILE. A file name 3454of '-' stands for the standard input. 3455 3456 If one file is a directory and the other is not, 'diff' compares the 3457file in the directory whose name is that of the non-directory. The 3458non-directory file must not be '-'. 3459 3460 If two file names are given and both are directories, 'diff' compares 3461corresponding files in both directories, in alphabetical order; this 3462comparison is not recursive unless the '--recursive' ('-r') option is 3463given. 'diff' never compares the actual contents of a directory as if 3464it were a file. The file that is fully specified may not be standard 3465input, because standard input is nameless and the notion of "file with 3466the same name" does not apply. 3467 3468 If the '--from-file=FILE' option is given, the number of file names 3469is arbitrary, and FILE is compared to each named file. Similarly, if 3470the '--to-file=FILE' option is given, each named file is compared to 3471FILE. 3472 3473 'diff' options begin with '-', so normally file names may not begin 3474with '-'. However, '--' as an argument by itself treats the remaining 3475arguments as file names even if they begin with '-'. 3476 3477 An exit status of 0 means no differences were found, 1 means some 3478differences were found, and 2 means trouble. 3479 3480* Menu: 3481 3482* diff Options:: Summary of options to 'diff'. 3483 3484 3485File: diffutils.info, Node: diff Options, Up: Invoking diff 3486 348713.1 Options to 'diff' 3488====================== 3489 3490Below is a summary of all of the options that GNU 'diff' accepts. Most 3491options have two equivalent names, one of which is a single letter 3492preceded by '-', and the other of which is a long name preceded by '--'. 3493Multiple single letter options (unless they take an argument) can be 3494combined into a single command line word: '-ac' is equivalent to '-a 3495-c'. Long named options can be abbreviated to any unique prefix of 3496their name. Brackets ([ and ]) indicate that an option takes an 3497optional argument. 3498 3499'-a' 3500'--text' 3501 Treat all files as text and compare them line-by-line, even if they 3502 do not seem to be text. *Note Binary::. 3503 3504'-b' 3505'--ignore-space-change' 3506 Ignore changes in amount of white space. *Note White Space::. 3507 3508'-B' 3509'--ignore-blank-lines' 3510 Ignore changes that just insert or delete blank lines. *Note Blank 3511 Lines::. 3512 3513'--binary' 3514 Read and write data in binary mode. *Note Binary::. 3515 3516'-c' 3517 Use the context output format, showing three lines of context. 3518 *Note Context Format::. 3519 3520'--color [=WHEN]' 3521 Specify whether to use color for distinguishing different contexts, 3522 like header, added or removed lines. WHEN may be omitted, or one 3523 of: 3524 * none Do not use color at all. This is the default when no 3525 -color option is specified. 3526 * auto Use color only if standard output is a terminal. 3527 * always Always use color. 3528 Specifying '--color' and no WHEN is equivalent to '--color=auto'. 3529 3530'-C LINES' 3531'--context[=LINES]' 3532 Use the context output format, showing LINES (an integer) lines of 3533 context, or three if LINES is not given. *Note Context Format::. 3534 For proper operation, 'patch' typically needs at least two lines of 3535 context. 3536 3537 For compatibility 'diff' also supports an obsolete option syntax 3538 '-LINES' that has effect when combined with '-c', '-p', or '-u'. 3539 New scripts should use '-U LINES' ('-C LINES') instead. 3540 3541'--changed-group-format=FORMAT' 3542 Use FORMAT to output a line group containing differing lines from 3543 both files in if-then-else format. *Note Line Group Formats::. 3544 3545'-d' 3546'--minimal' 3547 Change the algorithm perhaps find a smaller set of changes. This 3548 makes 'diff' slower (sometimes much slower). *Note diff 3549 Performance::. 3550 3551'-D NAME' 3552'--ifdef=NAME' 3553 Make merged '#ifdef' format output, conditional on the preprocessor 3554 macro NAME. *Note If-then-else::. 3555 3556'-e' 3557'--ed' 3558 Make output that is a valid 'ed' script. *Note ed Scripts::. 3559 3560'-E' 3561'--ignore-tab-expansion' 3562 Ignore changes due to tab expansion. *Note White Space::. 3563 3564'-f' 3565'--forward-ed' 3566 Make output that looks vaguely like an 'ed' script but has changes 3567 in the order they appear in the file. *Note Forward ed::. 3568 3569'-F REGEXP' 3570'--show-function-line=REGEXP' 3571 In context and unified format, for each hunk of differences, show 3572 some of the last preceding line that matches REGEXP. *Note 3573 Specified Headings::. 3574 3575'--from-file=FILE' 3576 Compare FILE to each operand; FILE may be a directory. 3577 3578'--help' 3579 Output a summary of usage and then exit. 3580 3581'--horizon-lines=LINES' 3582 Do not discard the last LINES lines of the common prefix and the 3583 first LINES lines of the common suffix. *Note diff Performance::. 3584 3585'-i' 3586'--ignore-case' 3587 Ignore changes in case; consider upper- and lower-case letters 3588 equivalent. *Note Case Folding::. 3589 3590'-I REGEXP' 3591'--ignore-matching-lines=REGEXP' 3592 Ignore changes that just insert or delete lines that match REGEXP. 3593 *Note Specified Lines::. 3594 3595'--ignore-file-name-case' 3596 Ignore case when comparing file names. For example, recursive 3597 comparison of 'd' to 'e' might compare the contents of 'd/Init' and 3598 'e/inIt'. At the top level, 'diff d inIt' might compare the 3599 contents of 'd/Init' and 'inIt'. *Note Comparing Directories::. 3600 3601'-l' 3602'--paginate' 3603 Pass the output through 'pr' to paginate it. *Note Pagination::. 3604 3605'-L LABEL' 3606'--label=LABEL' 3607 Use LABEL instead of the file name in the context format (*note 3608 Context Format::) and unified format (*note Unified Format::) 3609 headers. *Note RCS::. 3610 3611'--left-column' 3612 Print only the left column of two common lines in side by side 3613 format. *Note Side by Side Format::. 3614 3615'--line-format=FORMAT' 3616 Use FORMAT to output all input lines in if-then-else format. *Note 3617 Line Formats::. 3618 3619'-n' 3620'--rcs' 3621 Output RCS-format diffs; like '-f' except that each command 3622 specifies the number of lines affected. *Note RCS::. 3623 3624'-N' 3625'--new-file' 3626 If one file is missing, treat it as present but empty. *Note 3627 Comparing Directories::. 3628 3629'--new-group-format=FORMAT' 3630 Use FORMAT to output a group of lines taken from just the second 3631 file in if-then-else format. *Note Line Group Formats::. 3632 3633'--new-line-format=FORMAT' 3634 Use FORMAT to output a line taken from just the second file in 3635 if-then-else format. *Note Line Formats::. 3636 3637'--no-dereference' 3638 Act on symbolic links themselves instead of what they point to. 3639 Two symbolic links are deemed equal only when each points to 3640 precisely the same name. 3641 3642'--old-group-format=FORMAT' 3643 Use FORMAT to output a group of lines taken from just the first 3644 file in if-then-else format. *Note Line Group Formats::. 3645 3646'--old-line-format=FORMAT' 3647 Use FORMAT to output a line taken from just the first file in 3648 if-then-else format. *Note Line Formats::. 3649 3650'-p' 3651'--show-c-function' 3652 Show which C function each change is in. *Note C Function 3653 Headings::. 3654 3655'--palette=PALETTE' 3656 Specify what color palette to use when colored output is enabled. 3657 It defaults to 'rs=0:hd=1:ad=32:de=31:ln=36' for red deleted lines, 3658 green added lines, cyan line numbers, bold header. 3659 3660 Supported capabilities are as follows. 3661 3662 'ad=32' 3663 3664 SGR substring for added lines. The default is green 3665 foreground. 3666 3667 'de=31' 3668 3669 SGR substring for deleted lines. The default is red 3670 foreground. 3671 3672 'hd=1' 3673 3674 SGR substring for chunk header. The default is bold 3675 foreground. 3676 3677 'ln=36' 3678 3679 SGR substring for line numbers. The default is cyan 3680 foreground. 3681 3682'-q' 3683'--brief' 3684 Report only whether the files differ, not the details of the 3685 differences. *Note Brief::. 3686 3687'-r' 3688'--recursive' 3689 When comparing directories, recursively compare any subdirectories 3690 found. *Note Comparing Directories::. 3691 3692'-s' 3693'--report-identical-files' 3694 Report when two files are the same. *Note Comparing Directories::. 3695 3696'-S FILE' 3697'--starting-file=FILE' 3698 When comparing directories, start with the file FILE. This is used 3699 for resuming an aborted comparison. *Note Comparing Directories::. 3700 3701'--speed-large-files' 3702 Use heuristics to speed handling of large files that have numerous 3703 scattered small changes. *Note diff Performance::. 3704 3705'--strip-trailing-cr' 3706 Strip any trailing carriage return at the end of an input line. 3707 *Note Binary::. 3708 3709'--suppress-common-lines' 3710 Do not print common lines in side by side format. *Note Side by 3711 Side Format::. 3712 3713'-t' 3714'--expand-tabs' 3715 Expand tabs to spaces in the output, to preserve the alignment of 3716 tabs in the input files. *Note Tabs::. 3717 3718'-T' 3719'--initial-tab' 3720 Output a tab rather than a space before the text of a line in 3721 normal or context format. This causes the alignment of tabs in the 3722 line to look normal. *Note Tabs::. 3723 3724'--tabsize=COLUMNS' 3725 Assume that tab stops are set every COLUMNS (default 8) print 3726 columns. *Note Tabs::. 3727 3728'--suppress-blank-empty' 3729 Suppress any blanks before newlines when printing the 3730 representation of an empty line, when outputting normal, context, 3731 or unified format. *Note Trailing Blanks::. 3732 3733'--to-file=FILE' 3734 Compare each operand to FILE; FILE may be a directory. 3735 3736'-u' 3737 Use the unified output format, showing three lines of context. 3738 *Note Unified Format::. 3739 3740'--unchanged-group-format=FORMAT' 3741 Use FORMAT to output a group of common lines taken from both files 3742 in if-then-else format. *Note Line Group Formats::. 3743 3744'--unchanged-line-format=FORMAT' 3745 Use FORMAT to output a line common to both files in if-then-else 3746 format. *Note Line Formats::. 3747 3748'--unidirectional-new-file' 3749 If a first file is missing, treat it as present but empty. *Note 3750 Comparing Directories::. 3751 3752'-U LINES' 3753'--unified[=LINES]' 3754 Use the unified output format, showing LINES (an integer) lines of 3755 context, or three if LINES is not given. *Note Unified Format::. 3756 For proper operation, 'patch' typically needs at least two lines of 3757 context. 3758 3759 On older systems, 'diff' supports an obsolete option '-LINES' that 3760 has effect when combined with '-u'. POSIX 1003.1-2001 (*note 3761 Standards conformance::) does not allow this; use '-U LINES' 3762 instead. 3763 3764'-v' 3765'--version' 3766 Output version information and then exit. 3767 3768'-w' 3769'--ignore-all-space' 3770 Ignore white space when comparing lines. *Note White Space::. 3771 3772'-W COLUMNS' 3773'--width=COLUMNS' 3774 Output at most COLUMNS (default 130) print columns per line in side 3775 by side format. *Note Side by Side Format::. 3776 3777'-x PATTERN' 3778'--exclude=PATTERN' 3779 When comparing directories, ignore files and subdirectories whose 3780 basenames match PATTERN. *Note Comparing Directories::. 3781 3782'-X FILE' 3783'--exclude-from=FILE' 3784 When comparing directories, ignore files and subdirectories whose 3785 basenames match any pattern contained in FILE. *Note Comparing 3786 Directories::. 3787 3788'-y' 3789'--side-by-side' 3790 Use the side by side output format. *Note Side by Side Format::. 3791 3792'-Z' 3793'--ignore-trailing-space' 3794 Ignore white space at line end. *Note White Space::. 3795 3796 3797File: diffutils.info, Node: Invoking diff3, Next: Invoking patch, Prev: Invoking diff, Up: Top 3798 379914 Invoking 'diff3' 3800******************* 3801 3802The 'diff3' command compares three files and outputs descriptions of 3803their differences. Its arguments are as follows: 3804 3805 diff3 OPTIONS... MINE OLDER YOURS 3806 3807 The files to compare are MINE, OLDER, and YOURS. At most one of 3808these three file names may be '-', which tells 'diff3' to read the 3809standard input for that file. 3810 3811 An exit status of 0 means 'diff3' was successful, 1 means some 3812conflicts were found, and 2 means trouble. 3813 3814* Menu: 3815 3816* diff3 Options:: Summary of options to 'diff3'. 3817 3818 3819File: diffutils.info, Node: diff3 Options, Up: Invoking diff3 3820 382114.1 Options to 'diff3' 3822======================= 3823 3824Below is a summary of all of the options that GNU 'diff3' accepts. 3825Multiple single letter options (unless they take an argument) can be 3826combined into a single command line argument. 3827 3828'-a' 3829'--text' 3830 Treat all files as text and compare them line-by-line, even if they 3831 do not appear to be text. *Note Binary::. 3832 3833'-A' 3834'--show-all' 3835 Incorporate all unmerged changes from OLDER to YOURS into MINE, 3836 surrounding conflicts with bracket lines. *Note Marking 3837 Conflicts::. 3838 3839'--diff-program=PROGRAM' 3840 Use the compatible comparison program PROGRAM to compare files 3841 instead of 'diff'. 3842 3843'-e' 3844'--ed' 3845 Generate an 'ed' script that incorporates all the changes from 3846 OLDER to YOURS into MINE. *Note Which Changes::. 3847 3848'-E' 3849'--show-overlap' 3850 Like '-e', except bracket lines from overlapping changes' first and 3851 third files. *Note Marking Conflicts::. With '-E', an overlapping 3852 change looks like this: 3853 3854 <<<<<<< MINE 3855 lines from MINE 3856 ======= 3857 lines from YOURS 3858 >>>>>>> YOURS 3859 3860'--help' 3861 Output a summary of usage and then exit. 3862 3863'-i' 3864 Generate 'w' and 'q' commands at the end of the 'ed' script for 3865 System V compatibility. This option must be combined with one of 3866 the '-AeExX3' options, and may not be combined with '-m'. *Note 3867 Saving the Changed File::. 3868 3869'--label=LABEL' 3870 Use the label LABEL for the brackets output by the '-A', '-E' and 3871 '-X' options. This option may be given up to three times, one for 3872 each input file. The default labels are the names of the input 3873 files. Thus 'diff3 --label X --label Y --label Z -m A B C' acts 3874 like 'diff3 -m A B C', except that the output looks like it came 3875 from files named 'X', 'Y' and 'Z' rather than from files named 'A', 3876 'B' and 'C'. *Note Marking Conflicts::. 3877 3878'-m' 3879'--merge' 3880 Apply the edit script to the first file and send the result to 3881 standard output. Unlike piping the output from 'diff3' to 'ed', 3882 this works even for binary files and incomplete lines. '-A' is 3883 assumed if no edit script option is specified. *Note Bypassing 3884 ed::. 3885 3886'--strip-trailing-cr' 3887 Strip any trailing carriage return at the end of an input line. 3888 *Note Binary::. 3889 3890'-T' 3891'--initial-tab' 3892 Output a tab rather than two spaces before the text of a line in 3893 normal format. This causes the alignment of tabs in the line to 3894 look normal. *Note Tabs::. 3895 3896'-v' 3897'--version' 3898 Output version information and then exit. 3899 3900'-x' 3901'--overlap-only' 3902 Like '-e', except output only the overlapping changes. *Note Which 3903 Changes::. 3904 3905'-X' 3906 Like '-E', except output only the overlapping changes. In other 3907 words, like '-x', except bracket changes as in '-E'. *Note Marking 3908 Conflicts::. 3909 3910'-3' 3911'--easy-only' 3912 Like '-e', except output only the nonoverlapping changes. *Note 3913 Which Changes::. 3914 3915 3916File: diffutils.info, Node: Invoking patch, Next: Invoking sdiff, Prev: Invoking diff3, Up: Top 3917 391815 Invoking 'patch' 3919******************* 3920 3921Normally 'patch' is invoked like this: 3922 3923 patch <PATCHFILE 3924 3925 The full format for invoking 'patch' is: 3926 3927 patch OPTIONS... [ORIGFILE [PATCHFILE]] 3928 3929 You can also specify where to read the patch from with the '-i 3930PATCHFILE' or '--input=PATCHFILE' option. If you do not specify 3931PATCHFILE, or if PATCHFILE is '-', 'patch' reads the patch (that is, the 3932'diff' output) from the standard input. 3933 3934 If you do not specify an input file on the command line, 'patch' 3935tries to intuit from the "leading text" (any text in the patch that 3936comes before the 'diff' output) which file to edit. *Note Multiple 3937Patches::. 3938 3939 By default, 'patch' replaces the original input file with the patched 3940version, possibly after renaming the original file into a backup file 3941(*note Backup Names::, for a description of how 'patch' names backup 3942files). You can also specify where to put the output with the '-o FILE' 3943or '--output=FILE' option; however, do not use this option if FILE is 3944one of the input files. 3945 3946* Menu: 3947 3948* patch Options:: Summary table of options to 'patch'. 3949 3950 3951File: diffutils.info, Node: patch Options, Up: Invoking patch 3952 395315.1 Options to 'patch' 3954======================= 3955 3956Here is a summary of all of the options that GNU 'patch' accepts. *Note 3957patch and Tradition::, for which of these options are safe to use in 3958older versions of 'patch'. 3959 3960 Multiple single-letter options that do not take an argument can be 3961combined into a single command line argument with only one dash. 3962 3963'-b' 3964'--backup' 3965 Back up the original contents of each file, even if backups would 3966 normally not be made. *Note Backups::. 3967 3968'-B PREFIX' 3969'--prefix=PREFIX' 3970 Prepend PREFIX to backup file names. *Note Backup Names::. 3971 3972'--backup-if-mismatch' 3973 Back up the original contents of each file if the patch does not 3974 exactly match the file. This is the default behavior when not 3975 conforming to POSIX. *Note Backups::. 3976 3977'--binary' 3978 Read and write all files in binary mode, except for standard output 3979 and '/dev/tty'. This option has no effect on POSIX-conforming 3980 systems like GNU/Linux. On systems where this option makes a 3981 difference, the patch should be generated by 'diff -a --binary'. 3982 *Note Binary::. 3983 3984'-c' 3985'--context' 3986 Interpret the patch file as a context diff. *Note patch Input::. 3987 3988'-d DIRECTORY' 3989'--directory=DIRECTORY' 3990 Make directory DIRECTORY the current directory for interpreting 3991 both file names in the patch file, and file names given as 3992 arguments to other options. *Note patch Directories::. 3993 3994'-D NAME' 3995'--ifdef=NAME' 3996 Make merged if-then-else output using NAME. *Note If-then-else::. 3997 3998'--dry-run' 3999 Print the results of applying the patches without actually changing 4000 any files. *Note Dry Runs::. 4001 4002'-e' 4003'--ed' 4004 Interpret the patch file as an 'ed' script. *Note patch Input::. 4005 4006'-E' 4007'--remove-empty-files' 4008 Remove output files that are empty after the patches have been 4009 applied. *Note Creating and Removing::. 4010 4011'-f' 4012'--force' 4013 Assume that the user knows exactly what he or she is doing, and do 4014 not ask any questions. *Note patch Messages::. 4015 4016'-F LINES' 4017'--fuzz=LINES' 4018 Set the maximum fuzz factor to LINES. *Note Inexact::. 4019 4020'-g NUM' 4021'--get=NUM' 4022 If NUM is positive, get input files from a revision control system 4023 as necessary; if zero, do not get the files; if negative, ask the 4024 user whether to get the files. *Note Revision Control::. 4025 4026'--help' 4027 Output a summary of usage and then exit. 4028 4029'-i PATCHFILE' 4030'--input=PATCHFILE' 4031 Read the patch from PATCHFILE rather than from standard input. 4032 *Note patch Options::. 4033 4034'-l' 4035'--ignore-white-space' 4036 Let any sequence of blanks (spaces or tabs) in the patch file match 4037 any sequence of blanks in the input file. *Note Changed White 4038 Space::. 4039 4040'-n' 4041'--normal' 4042 Interpret the patch file as a normal diff. *Note patch Input::. 4043 4044'-N' 4045'--forward' 4046 Ignore patches that 'patch' thinks are reversed or already applied. 4047 See also '-R'. *Note Reversed Patches::. 4048 4049'--no-backup-if-mismatch' 4050 Do not back up the original contents of files. This is the default 4051 behavior when conforming to POSIX. *Note Backups::. 4052 4053'-o FILE' 4054'--output=FILE' 4055 Use FILE as the output file name. *Note patch Options::. 4056 4057'-pNUMBER' 4058'--strip=NUMBER' 4059 Set the file name strip count to NUMBER. *Note patch 4060 Directories::. 4061 4062'--posix' 4063 Conform to POSIX, as if the 'POSIXLY_CORRECT' environment variable 4064 had been set. *Note patch and POSIX::. 4065 4066'--quoting-style=WORD' 4067 Use style WORD to quote names in diagnostics, as if the 4068 'QUOTING_STYLE' environment variable had been set to WORD. *Note 4069 patch Quoting Style::. 4070 4071'-r REJECT-FILE' 4072'--reject-file=REJECT-FILE' 4073 Use REJECT-FILE as the reject file name. *Note Reject Names::. 4074 4075'-R' 4076'--reverse' 4077 Assume that this patch was created with the old and new files 4078 swapped. *Note Reversed Patches::. 4079 4080'-s' 4081'--quiet' 4082'--silent' 4083 Work silently unless an error occurs. *Note patch Messages::. 4084 4085'-t' 4086'--batch' 4087 Do not ask any questions. *Note patch Messages::. 4088 4089'-T' 4090'--set-time' 4091 Set the modification and access times of patched files from 4092 timestamps given in context diff headers, assuming that the context 4093 diff headers use local time. *Note Patching Timestamps::. 4094 4095'-u' 4096'--unified' 4097 Interpret the patch file as a unified diff. *Note patch Input::. 4098 4099'-v' 4100'--version' 4101 Output version information and then exit. 4102 4103'-V BACKUP-STYLE' 4104'--version=control=BACKUP-STYLE' 4105 Select the naming convention for backup file names. *Note Backup 4106 Names::. 4107 4108'--verbose' 4109 Print more diagnostics than usual. *Note patch Messages::. 4110 4111'-x NUMBER' 4112'--debug=NUMBER' 4113 Set internal debugging flags. Of interest only to 'patch' 4114 patchers. 4115 4116'-Y PREFIX' 4117'--basename-prefix=PREFIX' 4118 Prepend PREFIX to base names of backup files. *Note Backup 4119 Names::. 4120 4121'-z SUFFIX' 4122'--suffix=SUFFIX' 4123 Use SUFFIX as the backup extension instead of '.orig' or '~'. 4124 *Note Backup Names::. 4125 4126'-Z' 4127'--set-utc' 4128 Set the modification and access times of patched files from 4129 timestamps given in context diff headers, assuming that the context 4130 diff headers use UTC. *Note Patching Timestamps::. 4131 4132 4133File: diffutils.info, Node: Invoking sdiff, Next: Standards conformance, Prev: Invoking patch, Up: Top 4134 413516 Invoking 'sdiff' 4136******************* 4137 4138The 'sdiff' command merges two files and interactively outputs the 4139results. Its arguments are as follows: 4140 4141 sdiff -o OUTFILE OPTIONS... FROM-FILE TO-FILE 4142 4143 This merges FROM-FILE with TO-FILE, with output to OUTFILE. If 4144FROM-FILE is a directory and TO-FILE is not, 'sdiff' compares the file 4145in FROM-FILE whose file name is that of TO-FILE, and vice versa. 4146FROM-FILE and TO-FILE may not both be directories. 4147 4148 'sdiff' options begin with '-', so normally FROM-FILE and TO-FILE may 4149not begin with '-'. However, '--' as an argument by itself treats the 4150remaining arguments as file names even if they begin with '-'. You may 4151not use '-' as an input file. 4152 4153 'sdiff' without '--output' ('-o') produces a side-by-side difference. 4154This usage is obsolete; use the '--side-by-side' ('-y') option of 'diff' 4155instead. 4156 4157 An exit status of 0 means no differences were found, 1 means some 4158differences were found, and 2 means trouble. 4159 4160* Menu: 4161 4162* sdiff Options:: Summary of options to 'diff'. 4163 4164 4165File: diffutils.info, Node: sdiff Options, Up: Invoking sdiff 4166 416716.1 Options to 'sdiff' 4168======================= 4169 4170Below is a summary of all of the options that GNU 'sdiff' accepts. Each 4171option has two equivalent names, one of which is a single letter 4172preceded by '-', and the other of which is a long name preceded by '--'. 4173Multiple single letter options (unless they take an argument) can be 4174combined into a single command line argument. Long named options can be 4175abbreviated to any unique prefix of their name. 4176 4177'-a' 4178'--text' 4179 Treat all files as text and compare them line-by-line, even if they 4180 do not appear to be text. *Note Binary::. 4181 4182'-b' 4183'--ignore-space-change' 4184 Ignore changes in amount of white space. *Note White Space::. 4185 4186'-B' 4187'--ignore-blank-lines' 4188 Ignore changes that just insert or delete blank lines. *Note Blank 4189 Lines::. 4190 4191'-d' 4192'--minimal' 4193 Change the algorithm to perhaps find a smaller set of changes. 4194 This makes 'sdiff' slower (sometimes much slower). *Note diff 4195 Performance::. 4196 4197'--diff-program=PROGRAM' 4198 Use the compatible comparison program PROGRAM to compare files 4199 instead of 'diff'. 4200 4201'-E' 4202'--ignore-tab-expansion' 4203 Ignore changes due to tab expansion. *Note White Space::. 4204 4205'--help' 4206 Output a summary of usage and then exit. 4207 4208'-i' 4209'--ignore-case' 4210 Ignore changes in case; consider upper- and lower-case to be the 4211 same. *Note Case Folding::. 4212 4213'-I REGEXP' 4214'--ignore-matching-lines=REGEXP' 4215 Ignore changes that just insert or delete lines that match REGEXP. 4216 *Note Specified Lines::. 4217 4218'-l' 4219'--left-column' 4220 Print only the left column of two common lines. *Note Side by Side 4221 Format::. 4222 4223'-o FILE' 4224'--output=FILE' 4225 Put merged output into FILE. This option is required for merging. 4226 4227'-s' 4228'--suppress-common-lines' 4229 Do not print common lines. *Note Side by Side Format::. 4230 4231'--speed-large-files' 4232 Use heuristics to speed handling of large files that have numerous 4233 scattered small changes. *Note diff Performance::. 4234 4235'--strip-trailing-cr' 4236 Strip any trailing carriage return at the end of an input line. 4237 *Note Binary::. 4238 4239'-t' 4240'--expand-tabs' 4241 Expand tabs to spaces in the output, to preserve the alignment of 4242 tabs in the input files. *Note Tabs::. 4243 4244'--tabsize=COLUMNS' 4245 Assume that tab stops are set every COLUMNS (default 8) print 4246 columns. *Note Tabs::. 4247 4248'-v' 4249'--version' 4250 Output version information and then exit. 4251 4252'-w COLUMNS' 4253'--width=COLUMNS' 4254 Output at most COLUMNS (default 130) print columns per line. *Note 4255 Side by Side Format::. Note that for historical reasons, this 4256 option is '-W' in 'diff', '-w' in 'sdiff'. 4257 4258'-W' 4259'--ignore-all-space' 4260 Ignore white space when comparing lines. *Note White Space::. 4261 Note that for historical reasons, this option is '-w' in 'diff', 4262 '-W' in 'sdiff'. 4263 4264'-Z' 4265'--ignore-trailing-space' 4266 Ignore white space at line end. *Note White Space::. 4267 4268 4269File: diffutils.info, Node: Standards conformance, Next: Projects, Prev: Invoking sdiff, Up: Top 4270 427117 Standards conformance 4272************************ 4273 4274In a few cases, the GNU utilities' default behavior is incompatible with 4275the POSIX standard. To suppress these incompatibilities, define the 4276'POSIXLY_CORRECT' environment variable. Unless you are checking for 4277POSIX conformance, you probably do not need to define 'POSIXLY_CORRECT'. 4278 4279 Normally options and operands can appear in any order, and programs 4280act as if all the options appear before any operands. For example, 4281'diff lao tzu -C 2' acts like 'diff -C 2 lao tzu', since '2' is an 4282option-argument of '-C'. However, if the 'POSIXLY_CORRECT' environment 4283variable is set, options must appear before operands, unless otherwise 4284specified for a particular command. 4285 4286 Newer versions of POSIX are occasionally incompatible with older 4287versions. For example, older versions of POSIX allowed the command 4288'diff -c -10' to have the same meaning as 'diff -C 10', but POSIX 42891003.1-2001 'diff' no longer allows digit-string options like '-10'. 4290 4291 The GNU utilities normally conform to the version of POSIX that is 4292standard for your system. To cause them to conform to a different 4293version of POSIX, define the '_POSIX2_VERSION' environment variable to a 4294value of the form YYYYMM specifying the year and month the standard was 4295adopted. Two values are currently supported for '_POSIX2_VERSION': 4296'199209' stands for POSIX 1003.2-1992, and '200112' stands for POSIX 42971003.1-2001. For example, if you are running older software that 4298assumes an older version of POSIX and uses 'diff -c -10', you can work 4299around the compatibility problems by setting '_POSIX2_VERSION=199209' in 4300your environment. 4301 4302 4303File: diffutils.info, Node: Projects, Next: Copying This Manual, Prev: Standards conformance, Up: Top 4304 430518 Future Projects 4306****************** 4307 4308Here are some ideas for improving GNU 'diff' and 'patch'. The GNU 4309project has identified some improvements as potential programming 4310projects for volunteers. You can also help by reporting any bugs that 4311you find. 4312 4313 If you are a programmer and would like to contribute something to the 4314GNU project, please consider volunteering for one of these projects. If 4315you are seriously contemplating work, please write to <gvc@gnu.org> to 4316coordinate with other volunteers. 4317 4318* Menu: 4319 4320* Shortcomings:: Suggested projects for improvements. 4321* Bugs:: Reporting bugs. 4322 4323 4324File: diffutils.info, Node: Shortcomings, Next: Bugs, Up: Projects 4325 432618.1 Suggested Projects for Improving GNU 'diff' and 'patch' 4327============================================================ 4328 4329One should be able to use GNU 'diff' to generate a patch from any pair 4330of directory trees, and given the patch and a copy of one such tree, use 4331'patch' to generate a faithful copy of the other. Unfortunately, some 4332changes to directory trees cannot be expressed using current patch 4333formats; also, 'patch' does not handle some of the existing formats. 4334These shortcomings motivate the following suggested projects. 4335 4336* Menu: 4337 4338* Internationalization:: Handling multibyte and varying-width characters. 4339* Changing Structure:: Handling changes to the directory structure. 4340* Special Files:: Handling symbolic links, device special files, etc. 4341* Unusual File Names:: Handling file names that contain unusual characters. 4342* Timestamp Order:: Outputting diffs in timestamp order. 4343* Ignoring Changes:: Ignoring certain changes while showing others. 4344* Speedups:: Improving performance. 4345 4346 4347File: diffutils.info, Node: Internationalization, Next: Changing Structure, Up: Shortcomings 4348 434918.1.1 Handling Multibyte and Varying-Width Characters 4350------------------------------------------------------ 4351 4352'diff', 'diff3' and 'sdiff' treat each line of input as a string of 4353unibyte characters. This can mishandle multibyte characters in some 4354cases. For example, when asked to ignore spaces, 'diff' does not 4355properly ignore a multibyte space character. 4356 4357 Also, 'diff' currently assumes that each byte is one column wide, and 4358this assumption is incorrect in some locales, e.g., locales that use 4359UTF-8 encoding. This causes problems with the '-y' or '--side-by-side' 4360option of 'diff'. 4361 4362 These problems need to be fixed without unduly affecting the 4363performance of the utilities in unibyte environments. 4364 4365 The IBM GNU/Linux Technology Center Internationalization Team has 4366proposed patches to support internationalized 'diff' 4367(http://oss.software.ibm.com/developer/opensource/linux/patches/i18n/diffutils-2.7.2-i18n-0.1.patch.gz). 4368Unfortunately, these patches are incomplete and are to an older version 4369of 'diff', so more work needs to be done in this area. 4370 4371 4372File: diffutils.info, Node: Changing Structure, Next: Special Files, Prev: Internationalization, Up: Shortcomings 4373 437418.1.2 Handling Changes to the Directory Structure 4375-------------------------------------------------- 4376 4377'diff' and 'patch' do not handle some changes to directory structure. 4378For example, suppose one directory tree contains a directory named 'D' 4379with some subsidiary files, and another contains a file with the same 4380name 'D'. 'diff -r' does not output enough information for 'patch' to 4381transform the directory subtree into the file. 4382 4383 There should be a way to specify that a file has been removed without 4384having to include its entire contents in the patch file. There should 4385also be a way to tell 'patch' that a file was renamed, even if there is 4386no way for 'diff' to generate such information. There should be a way 4387to tell 'patch' that a file's timestamp has changed, even if its 4388contents have not changed. 4389 4390 These problems can be fixed by extending the 'diff' output format to 4391represent changes in directory structure, and extending 'patch' to 4392understand these extensions. 4393 4394 4395File: diffutils.info, Node: Special Files, Next: Unusual File Names, Prev: Changing Structure, Up: Shortcomings 4396 439718.1.3 Files that are Neither Directories Nor Regular Files 4398----------------------------------------------------------- 4399 4400Some files are neither directories nor regular files: they are unusual 4401files like symbolic links, device special files, named pipes, and 4402sockets. Currently, 'diff' treats symbolic links as if they were the 4403pointed-to files, except that a recursive 'diff' reports an error if it 4404detects infinite loops of symbolic links (e.g., symbolic links to '..'). 4405'diff' treats other special files like regular files if they are 4406specified at the top level, but simply reports their presence when 4407comparing directories. This means that 'patch' cannot represent changes 4408to such files. For example, if you change which file a symbolic link 4409points to, 'diff' outputs the difference between the two files, instead 4410of the change to the symbolic link. 4411 4412 'diff' should optionally report changes to special files specially, 4413and 'patch' should be extended to understand these extensions. 4414 4415 4416File: diffutils.info, Node: Unusual File Names, Next: Timestamp Order, Prev: Special Files, Up: Shortcomings 4417 441818.1.4 File Names that Contain Unusual Characters 4419------------------------------------------------- 4420 4421When a file name contains an unusual character like a newline or white 4422space, 'diff -r' generates a patch that 'patch' cannot parse. The 4423problem is with format of 'diff' output, not just with 'patch', because 4424with odd enough file names one can cause 'diff' to generate a patch that 4425is syntactically correct but patches the wrong files. The format of 4426'diff' output should be extended to handle all possible file names. 4427 4428 4429File: diffutils.info, Node: Timestamp Order, Next: Ignoring Changes, Prev: Unusual File Names, Up: Shortcomings 4430 443118.1.5 Outputting Diffs in Timestamp Order 4432------------------------------------------ 4433 4434Applying 'patch' to a multiple-file diff can result in files whose 4435timestamps are out of order. GNU 'patch' has options to restore the 4436timestamps of the updated files (*note Patching Timestamps::), but 4437sometimes it is useful to generate a patch that works even if the 4438recipient does not have GNU patch, or does not use these options. One 4439way to do this would be to implement a 'diff' option to output diffs in 4440timestamp order. 4441 4442 4443File: diffutils.info, Node: Ignoring Changes, Next: Speedups, Prev: Timestamp Order, Up: Shortcomings 4444 444518.1.6 Ignoring Certain Changes 4446------------------------------- 4447 4448It would be nice to have a feature for specifying two strings, one in 4449FROM-FILE and one in TO-FILE, which should be considered to match. 4450Thus, if the two strings are 'foo' and 'bar', then if two lines differ 4451only in that 'foo' in file 1 corresponds to 'bar' in file 2, the lines 4452are treated as identical. 4453 4454 It is not clear how general this feature can or should be, or what 4455syntax should be used for it. 4456 4457 A partial substitute is to filter one or both files before comparing, 4458e.g.: 4459 4460 sed 's/foo/bar/g' file1 | diff - file2 4461 4462 However, this outputs the filtered text, not the original. 4463 4464 4465File: diffutils.info, Node: Speedups, Prev: Ignoring Changes, Up: Shortcomings 4466 446718.1.7 Improving Performance 4468---------------------------- 4469 4470When comparing two large directory structures, one of which was 4471originally copied from the other with timestamps preserved (e.g., with 4472'cp -pR'), it would greatly improve performance if an option told 'diff' 4473to assume that two files with the same size and timestamps have the same 4474content. *Note diff Performance::. 4475 4476 4477File: diffutils.info, Node: Bugs, Prev: Shortcomings, Up: Projects 4478 447918.2 Reporting Bugs 4480=================== 4481 4482If you think you have found a bug in GNU 'cmp', 'diff', 'diff3', or 4483'sdiff', please report it by electronic mail to the GNU utilities bug 4484report mailing list (http://mail.gnu.org/mailman/listinfo/bug-diffutils) 4485<bug-diffutils@gnu.org>. Please send bug reports for GNU 'patch' to 4486<bug-patch@gnu.org>. Send as precise a description of the problem as 4487you can, including the output of the '--version' option and sample input 4488files that produce the bug, if applicable. If you have a nontrivial fix 4489for the bug, please send it as well. If you have a patch, please send 4490it too. It may simplify the maintainer's job if the patch is relative 4491to a recent test release, which you can find in the directory 4492<ftp://alpha.gnu.org/gnu/diffutils/>. 4493 4494 4495File: diffutils.info, Node: Copying This Manual, Next: Translations, Prev: Projects, Up: Top 4496 4497Appendix A Copying This Manual 4498****************************** 4499 4500 Version 1.3, 3 November 2008 4501 4502 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. 4503 <https://fsf.org/> 4504 4505 Everyone is permitted to copy and distribute verbatim copies 4506 of this license document, but changing it is not allowed. 4507 4508 0. PREAMBLE 4509 4510 The purpose of this License is to make a manual, textbook, or other 4511 functional and useful document "free" in the sense of freedom: to 4512 assure everyone the effective freedom to copy and redistribute it, 4513 with or without modifying it, either commercially or 4514 noncommercially. Secondarily, this License preserves for the 4515 author and publisher a way to get credit for their work, while not 4516 being considered responsible for modifications made by others. 4517 4518 This License is a kind of "copyleft", which means that derivative 4519 works of the document must themselves be free in the same sense. 4520 It complements the GNU General Public License, which is a copyleft 4521 license designed for free software. 4522 4523 We have designed this License in order to use it for manuals for 4524 free software, because free software needs free documentation: a 4525 free program should come with manuals providing the same freedoms 4526 that the software does. But this License is not limited to 4527 software manuals; it can be used for any textual work, regardless 4528 of subject matter or whether it is published as a printed book. We 4529 recommend this License principally for works whose purpose is 4530 instruction or reference. 4531 4532 1. APPLICABILITY AND DEFINITIONS 4533 4534 This License applies to any manual or other work, in any medium, 4535 that contains a notice placed by the copyright holder saying it can 4536 be distributed under the terms of this License. Such a notice 4537 grants a world-wide, royalty-free license, unlimited in duration, 4538 to use that work under the conditions stated herein. The 4539 "Document", below, refers to any such manual or work. Any member 4540 of the public is a licensee, and is addressed as "you". You accept 4541 the license if you copy, modify or distribute the work in a way 4542 requiring permission under copyright law. 4543 4544 A "Modified Version" of the Document means any work containing the 4545 Document or a portion of it, either copied verbatim, or with 4546 modifications and/or translated into another language. 4547 4548 A "Secondary Section" is a named appendix or a front-matter section 4549 of the Document that deals exclusively with the relationship of the 4550 publishers or authors of the Document to the Document's overall 4551 subject (or to related matters) and contains nothing that could 4552 fall directly within that overall subject. (Thus, if the Document 4553 is in part a textbook of mathematics, a Secondary Section may not 4554 explain any mathematics.) The relationship could be a matter of 4555 historical connection with the subject or with related matters, or 4556 of legal, commercial, philosophical, ethical or political position 4557 regarding them. 4558 4559 The "Invariant Sections" are certain Secondary Sections whose 4560 titles are designated, as being those of Invariant Sections, in the 4561 notice that says that the Document is released under this License. 4562 If a section does not fit the above definition of Secondary then it 4563 is not allowed to be designated as Invariant. The Document may 4564 contain zero Invariant Sections. If the Document does not identify 4565 any Invariant Sections then there are none. 4566 4567 The "Cover Texts" are certain short passages of text that are 4568 listed, as Front-Cover Texts or Back-Cover Texts, in the notice 4569 that says that the Document is released under this License. A 4570 Front-Cover Text may be at most 5 words, and a Back-Cover Text may 4571 be at most 25 words. 4572 4573 A "Transparent" copy of the Document means a machine-readable copy, 4574 represented in a format whose specification is available to the 4575 general public, that is suitable for revising the document 4576 straightforwardly with generic text editors or (for images composed 4577 of pixels) generic paint programs or (for drawings) some widely 4578 available drawing editor, and that is suitable for input to text 4579 formatters or for automatic translation to a variety of formats 4580 suitable for input to text formatters. A copy made in an otherwise 4581 Transparent file format whose markup, or absence of markup, has 4582 been arranged to thwart or discourage subsequent modification by 4583 readers is not Transparent. An image format is not Transparent if 4584 used for any substantial amount of text. A copy that is not 4585 "Transparent" is called "Opaque". 4586 4587 Examples of suitable formats for Transparent copies include plain 4588 ASCII without markup, Texinfo input format, LaTeX input format, 4589 SGML or XML using a publicly available DTD, and standard-conforming 4590 simple HTML, PostScript or PDF designed for human modification. 4591 Examples of transparent image formats include PNG, XCF and JPG. 4592 Opaque formats include proprietary formats that can be read and 4593 edited only by proprietary word processors, SGML or XML for which 4594 the DTD and/or processing tools are not generally available, and 4595 the machine-generated HTML, PostScript or PDF produced by some word 4596 processors for output purposes only. 4597 4598 The "Title Page" means, for a printed book, the title page itself, 4599 plus such following pages as are needed to hold, legibly, the 4600 material this License requires to appear in the title page. For 4601 works in formats which do not have any title page as such, "Title 4602 Page" means the text near the most prominent appearance of the 4603 work's title, preceding the beginning of the body of the text. 4604 4605 The "publisher" means any person or entity that distributes copies 4606 of the Document to the public. 4607 4608 A section "Entitled XYZ" means a named subunit of the Document 4609 whose title either is precisely XYZ or contains XYZ in parentheses 4610 following text that translates XYZ in another language. (Here XYZ 4611 stands for a specific section name mentioned below, such as 4612 "Acknowledgements", "Dedications", "Endorsements", or "History".) 4613 To "Preserve the Title" of such a section when you modify the 4614 Document means that it remains a section "Entitled XYZ" according 4615 to this definition. 4616 4617 The Document may include Warranty Disclaimers next to the notice 4618 which states that this License applies to the Document. These 4619 Warranty Disclaimers are considered to be included by reference in 4620 this License, but only as regards disclaiming warranties: any other 4621 implication that these Warranty Disclaimers may have is void and 4622 has no effect on the meaning of this License. 4623 4624 2. VERBATIM COPYING 4625 4626 You may copy and distribute the Document in any medium, either 4627 commercially or noncommercially, provided that this License, the 4628 copyright notices, and the license notice saying this License 4629 applies to the Document are reproduced in all copies, and that you 4630 add no other conditions whatsoever to those of this License. You 4631 may not use technical measures to obstruct or control the reading 4632 or further copying of the copies you make or distribute. However, 4633 you may accept compensation in exchange for copies. If you 4634 distribute a large enough number of copies you must also follow the 4635 conditions in section 3. 4636 4637 You may also lend copies, under the same conditions stated above, 4638 and you may publicly display copies. 4639 4640 3. COPYING IN QUANTITY 4641 4642 If you publish printed copies (or copies in media that commonly 4643 have printed covers) of the Document, numbering more than 100, and 4644 the Document's license notice requires Cover Texts, you must 4645 enclose the copies in covers that carry, clearly and legibly, all 4646 these Cover Texts: Front-Cover Texts on the front cover, and 4647 Back-Cover Texts on the back cover. Both covers must also clearly 4648 and legibly identify you as the publisher of these copies. The 4649 front cover must present the full title with all words of the title 4650 equally prominent and visible. You may add other material on the 4651 covers in addition. Copying with changes limited to the covers, as 4652 long as they preserve the title of the Document and satisfy these 4653 conditions, can be treated as verbatim copying in other respects. 4654 4655 If the required texts for either cover are too voluminous to fit 4656 legibly, you should put the first ones listed (as many as fit 4657 reasonably) on the actual cover, and continue the rest onto 4658 adjacent pages. 4659 4660 If you publish or distribute Opaque copies of the Document 4661 numbering more than 100, you must either include a machine-readable 4662 Transparent copy along with each Opaque copy, or state in or with 4663 each Opaque copy a computer-network location from which the general 4664 network-using public has access to download using public-standard 4665 network protocols a complete Transparent copy of the Document, free 4666 of added material. If you use the latter option, you must take 4667 reasonably prudent steps, when you begin distribution of Opaque 4668 copies in quantity, to ensure that this Transparent copy will 4669 remain thus accessible at the stated location until at least one 4670 year after the last time you distribute an Opaque copy (directly or 4671 through your agents or retailers) of that edition to the public. 4672 4673 It is requested, but not required, that you contact the authors of 4674 the Document well before redistributing any large number of copies, 4675 to give them a chance to provide you with an updated version of the 4676 Document. 4677 4678 4. MODIFICATIONS 4679 4680 You may copy and distribute a Modified Version of the Document 4681 under the conditions of sections 2 and 3 above, provided that you 4682 release the Modified Version under precisely this License, with the 4683 Modified Version filling the role of the Document, thus licensing 4684 distribution and modification of the Modified Version to whoever 4685 possesses a copy of it. In addition, you must do these things in 4686 the Modified Version: 4687 4688 A. Use in the Title Page (and on the covers, if any) a title 4689 distinct from that of the Document, and from those of previous 4690 versions (which should, if there were any, be listed in the 4691 History section of the Document). You may use the same title 4692 as a previous version if the original publisher of that 4693 version gives permission. 4694 4695 B. List on the Title Page, as authors, one or more persons or 4696 entities responsible for authorship of the modifications in 4697 the Modified Version, together with at least five of the 4698 principal authors of the Document (all of its principal 4699 authors, if it has fewer than five), unless they release you 4700 from this requirement. 4701 4702 C. State on the Title page the name of the publisher of the 4703 Modified Version, as the publisher. 4704 4705 D. Preserve all the copyright notices of the Document. 4706 4707 E. Add an appropriate copyright notice for your modifications 4708 adjacent to the other copyright notices. 4709 4710 F. Include, immediately after the copyright notices, a license 4711 notice giving the public permission to use the Modified 4712 Version under the terms of this License, in the form shown in 4713 the Addendum below. 4714 4715 G. Preserve in that license notice the full lists of Invariant 4716 Sections and required Cover Texts given in the Document's 4717 license notice. 4718 4719 H. Include an unaltered copy of this License. 4720 4721 I. Preserve the section Entitled "History", Preserve its Title, 4722 and add to it an item stating at least the title, year, new 4723 authors, and publisher of the Modified Version as given on the 4724 Title Page. If there is no section Entitled "History" in the 4725 Document, create one stating the title, year, authors, and 4726 publisher of the Document as given on its Title Page, then add 4727 an item describing the Modified Version as stated in the 4728 previous sentence. 4729 4730 J. Preserve the network location, if any, given in the Document 4731 for public access to a Transparent copy of the Document, and 4732 likewise the network locations given in the Document for 4733 previous versions it was based on. These may be placed in the 4734 "History" section. You may omit a network location for a work 4735 that was published at least four years before the Document 4736 itself, or if the original publisher of the version it refers 4737 to gives permission. 4738 4739 K. For any section Entitled "Acknowledgements" or "Dedications", 4740 Preserve the Title of the section, and preserve in the section 4741 all the substance and tone of each of the contributor 4742 acknowledgements and/or dedications given therein. 4743 4744 L. Preserve all the Invariant Sections of the Document, unaltered 4745 in their text and in their titles. Section numbers or the 4746 equivalent are not considered part of the section titles. 4747 4748 M. Delete any section Entitled "Endorsements". Such a section 4749 may not be included in the Modified Version. 4750 4751 N. Do not retitle any existing section to be Entitled 4752 "Endorsements" or to conflict in title with any Invariant 4753 Section. 4754 4755 O. Preserve any Warranty Disclaimers. 4756 4757 If the Modified Version includes new front-matter sections or 4758 appendices that qualify as Secondary Sections and contain no 4759 material copied from the Document, you may at your option designate 4760 some or all of these sections as invariant. To do this, add their 4761 titles to the list of Invariant Sections in the Modified Version's 4762 license notice. These titles must be distinct from any other 4763 section titles. 4764 4765 You may add a section Entitled "Endorsements", provided it contains 4766 nothing but endorsements of your Modified Version by various 4767 parties--for example, statements of peer review or that the text 4768 has been approved by an organization as the authoritative 4769 definition of a standard. 4770 4771 You may add a passage of up to five words as a Front-Cover Text, 4772 and a passage of up to 25 words as a Back-Cover Text, to the end of 4773 the list of Cover Texts in the Modified Version. Only one passage 4774 of Front-Cover Text and one of Back-Cover Text may be added by (or 4775 through arrangements made by) any one entity. If the Document 4776 already includes a cover text for the same cover, previously added 4777 by you or by arrangement made by the same entity you are acting on 4778 behalf of, you may not add another; but you may replace the old 4779 one, on explicit permission from the previous publisher that added 4780 the old one. 4781 4782 The author(s) and publisher(s) of the Document do not by this 4783 License give permission to use their names for publicity for or to 4784 assert or imply endorsement of any Modified Version. 4785 4786 5. COMBINING DOCUMENTS 4787 4788 You may combine the Document with other documents released under 4789 this License, under the terms defined in section 4 above for 4790 modified versions, provided that you include in the combination all 4791 of the Invariant Sections of all of the original documents, 4792 unmodified, and list them all as Invariant Sections of your 4793 combined work in its license notice, and that you preserve all 4794 their Warranty Disclaimers. 4795 4796 The combined work need only contain one copy of this License, and 4797 multiple identical Invariant Sections may be replaced with a single 4798 copy. If there are multiple Invariant Sections with the same name 4799 but different contents, make the title of each such section unique 4800 by adding at the end of it, in parentheses, the name of the 4801 original author or publisher of that section if known, or else a 4802 unique number. Make the same adjustment to the section titles in 4803 the list of Invariant Sections in the license notice of the 4804 combined work. 4805 4806 In the combination, you must combine any sections Entitled 4807 "History" in the various original documents, forming one section 4808 Entitled "History"; likewise combine any sections Entitled 4809 "Acknowledgements", and any sections Entitled "Dedications". You 4810 must delete all sections Entitled "Endorsements." 4811 4812 6. COLLECTIONS OF DOCUMENTS 4813 4814 You may make a collection consisting of the Document and other 4815 documents released under this License, and replace the individual 4816 copies of this License in the various documents with a single copy 4817 that is included in the collection, provided that you follow the 4818 rules of this License for verbatim copying of each of the documents 4819 in all other respects. 4820 4821 You may extract a single document from such a collection, and 4822 distribute it individually under this License, provided you insert 4823 a copy of this License into the extracted document, and follow this 4824 License in all other respects regarding verbatim copying of that 4825 document. 4826 4827 7. AGGREGATION WITH INDEPENDENT WORKS 4828 4829 A compilation of the Document or its derivatives with other 4830 separate and independent documents or works, in or on a volume of a 4831 storage or distribution medium, is called an "aggregate" if the 4832 copyright resulting from the compilation is not used to limit the 4833 legal rights of the compilation's users beyond what the individual 4834 works permit. When the Document is included in an aggregate, this 4835 License does not apply to the other works in the aggregate which 4836 are not themselves derivative works of the Document. 4837 4838 If the Cover Text requirement of section 3 is applicable to these 4839 copies of the Document, then if the Document is less than one half 4840 of the entire aggregate, the Document's Cover Texts may be placed 4841 on covers that bracket the Document within the aggregate, or the 4842 electronic equivalent of covers if the Document is in electronic 4843 form. Otherwise they must appear on printed covers that bracket 4844 the whole aggregate. 4845 4846 8. TRANSLATION 4847 4848 Translation is considered a kind of modification, so you may 4849 distribute translations of the Document under the terms of section 4850 4. Replacing Invariant Sections with translations requires special 4851 permission from their copyright holders, but you may include 4852 translations of some or all Invariant Sections in addition to the 4853 original versions of these Invariant Sections. You may include a 4854 translation of this License, and all the license notices in the 4855 Document, and any Warranty Disclaimers, provided that you also 4856 include the original English version of this License and the 4857 original versions of those notices and disclaimers. In case of a 4858 disagreement between the translation and the original version of 4859 this License or a notice or disclaimer, the original version will 4860 prevail. 4861 4862 If a section in the Document is Entitled "Acknowledgements", 4863 "Dedications", or "History", the requirement (section 4) to 4864 Preserve its Title (section 1) will typically require changing the 4865 actual title. 4866 4867 9. TERMINATION 4868 4869 You may not copy, modify, sublicense, or distribute the Document 4870 except as expressly provided under this License. Any attempt 4871 otherwise to copy, modify, sublicense, or distribute it is void, 4872 and will automatically terminate your rights under this License. 4873 4874 However, if you cease all violation of this License, then your 4875 license from a particular copyright holder is reinstated (a) 4876 provisionally, unless and until the copyright holder explicitly and 4877 finally terminates your license, and (b) permanently, if the 4878 copyright holder fails to notify you of the violation by some 4879 reasonable means prior to 60 days after the cessation. 4880 4881 Moreover, your license from a particular copyright holder is 4882 reinstated permanently if the copyright holder notifies you of the 4883 violation by some reasonable means, this is the first time you have 4884 received notice of violation of this License (for any work) from 4885 that copyright holder, and you cure the violation prior to 30 days 4886 after your receipt of the notice. 4887 4888 Termination of your rights under this section does not terminate 4889 the licenses of parties who have received copies or rights from you 4890 under this License. If your rights have been terminated and not 4891 permanently reinstated, receipt of a copy of some or all of the 4892 same material does not give you any rights to use it. 4893 4894 10. FUTURE REVISIONS OF THIS LICENSE 4895 4896 The Free Software Foundation may publish new, revised versions of 4897 the GNU Free Documentation License from time to time. Such new 4898 versions will be similar in spirit to the present version, but may 4899 differ in detail to address new problems or concerns. See 4900 <https://www.gnu.org/copyleft/>. 4901 4902 Each version of the License is given a distinguishing version 4903 number. If the Document specifies that a particular numbered 4904 version of this License "or any later version" applies to it, you 4905 have the option of following the terms and conditions either of 4906 that specified version or of any later version that has been 4907 published (not as a draft) by the Free Software Foundation. If the 4908 Document does not specify a version number of this License, you may 4909 choose any version ever published (not as a draft) by the Free 4910 Software Foundation. If the Document specifies that a proxy can 4911 decide which future versions of this License can be used, that 4912 proxy's public statement of acceptance of a version permanently 4913 authorizes you to choose that version for the Document. 4914 4915 11. RELICENSING 4916 4917 "Massive Multiauthor Collaboration Site" (or "MMC Site") means any 4918 World Wide Web server that publishes copyrightable works and also 4919 provides prominent facilities for anybody to edit those works. A 4920 public wiki that anybody can edit is an example of such a server. 4921 A "Massive Multiauthor Collaboration" (or "MMC") contained in the 4922 site means any set of copyrightable works thus published on the MMC 4923 site. 4924 4925 "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 4926 license published by Creative Commons Corporation, a not-for-profit 4927 corporation with a principal place of business in San Francisco, 4928 California, as well as future copyleft versions of that license 4929 published by that same organization. 4930 4931 "Incorporate" means to publish or republish a Document, in whole or 4932 in part, as part of another Document. 4933 4934 An MMC is "eligible for relicensing" if it is licensed under this 4935 License, and if all works that were first published under this 4936 License somewhere other than this MMC, and subsequently 4937 incorporated in whole or in part into the MMC, (1) had no cover 4938 texts or invariant sections, and (2) were thus incorporated prior 4939 to November 1, 2008. 4940 4941 The operator of an MMC Site may republish an MMC contained in the 4942 site under CC-BY-SA on the same site at any time before August 1, 4943 2009, provided the MMC is eligible for relicensing. 4944 4945ADDENDUM: How to use this License for your documents 4946==================================================== 4947 4948To use this License in a document you have written, include a copy of 4949the License in the document and put the following copyright and license 4950notices just after the title page: 4951 4952 Copyright (C) YEAR YOUR NAME. 4953 Permission is granted to copy, distribute and/or modify this document 4954 under the terms of the GNU Free Documentation License, Version 1.3 4955 or any later version published by the Free Software Foundation; 4956 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover 4957 Texts. A copy of the license is included in the section entitled ``GNU 4958 Free Documentation License''. 4959 4960 If you have Invariant Sections, Front-Cover Texts and Back-Cover 4961Texts, replace the "with...Texts." line with this: 4962 4963 with the Invariant Sections being LIST THEIR TITLES, with 4964 the Front-Cover Texts being LIST, and with the Back-Cover Texts 4965 being LIST. 4966 4967 If you have Invariant Sections without Cover Texts, or some other 4968combination of the three, merge those two alternatives to suit the 4969situation. 4970 4971 If your document contains nontrivial examples of program code, we 4972recommend releasing these examples in parallel under your choice of free 4973software license, such as the GNU General Public License, to permit 4974their use in free software. 4975 4976 4977File: diffutils.info, Node: Translations, Next: Index, Prev: Copying This Manual, Up: Top 4978 4979Appendix B Translations of This Manual 4980************************************** 4981 4982Nishio Futoshi of the GNUjdoc project has prepared a Japanese 4983translation of this manual. Its most recent version can be found at 4984<http://openlab.ring.gr.jp/gnujdoc/cvsweb/cvsweb.cgi/gnujdoc/>. 4985 4986 4987File: diffutils.info, Node: Index, Prev: Translations, Up: Top 4988 4989Appendix C Index 4990**************** 4991 4992�[index�] 4993* Menu: 4994 4995* ! output format: Context. (line 6) 4996* +- output format: Unified Format. (line 6) 4997* < output format: Normal. (line 6) 4998* <<<<<<< for marking conflicts: Marking Conflicts. (line 6) 4999* _POSIX2_VERSION: Standards conformance. 5000 (line 23) 5001* ad capability: diff Options. (line 179) 5002* aligning tab stops: Tabs. (line 6) 5003* alternate file names: Alternate Names. (line 6) 5004* always color option: diff Options. (line 43) 5005* auto color option: diff Options. (line 42) 5006* backup file names: Backup Names. (line 6) 5007* backup file strategy: Backups. (line 6) 5008* binary file diff: Binary. (line 6) 5009* blank and tab difference suppression: White Space. (line 6) 5010* blank line difference suppression: Blank Lines. (line 6) 5011* brief difference reports: Brief. (line 6) 5012* bug reports: Bugs. (line 6) 5013* C function headings: C Function Headings. (line 6) 5014* C if-then-else output format: If-then-else. (line 6) 5015* case difference suppression: Case Folding. (line 6) 5016* ClearCase: Revision Control. (line 6) 5017* cmp invocation: Invoking cmp. (line 6) 5018* cmp options: cmp Options. (line 6) 5019* color, distinguishing different context: diff Options. (line 37) 5020* columnar output: Side by Side. (line 6) 5021* common mistakes with patches: Avoiding Common Mistakes. 5022 (line 6) 5023* comparing three files: Comparing Three Files. 5024 (line 6) 5025* conflict: diff3 Merging. (line 26) 5026* conflict marking: Marking Conflicts. (line 6) 5027* context output format: Context. (line 6) 5028* creating files: Creating and Removing. 5029 (line 6) 5030* de capability: diff Options. (line 184) 5031* diagnostics from patch: patch Messages. (line 6) 5032* diff invocation: Invoking diff. (line 6) 5033* diff merging: Interactive Merging. (line 6) 5034* diff options: diff Options. (line 6) 5035* diff sample input: Sample diff Input. (line 6) 5036* diff3 hunks: diff3 Hunks. (line 6) 5037* diff3 invocation: Invoking diff3. (line 6) 5038* diff3 options: diff3 Options. (line 6) 5039* diff3 sample input: Sample diff3 Input. (line 6) 5040* directories and patch: patch Directories. (line 6) 5041* directory structure changes: Changing Structure. (line 6) 5042* dry runs for patch: Dry Runs. (line 6) 5043* ed script output format: ed Scripts. (line 6) 5044* EDITOR: Merge Commands. (line 50) 5045* empty files, removing: Creating and Removing. 5046 (line 6) 5047* exabyte, definition of: cmp Options. (line 99) 5048* exbibyte, definition of: cmp Options. (line 102) 5049* file name alternates: Alternate Names. (line 6) 5050* file names with unusual characters: Unusual File Names. (line 6) 5051* format of diff output: Output Formats. (line 6) 5052* format of diff3 output: Comparing Three Files. 5053 (line 6) 5054* formats for if-then-else line groups: Line Group Formats. (line 6) 5055* forward ed script output format: Forward ed. (line 6) 5056* full lines: Incomplete Lines. (line 6) 5057* function headings, C: C Function Headings. (line 6) 5058* fuzz factor when patching: Inexact. (line 6) 5059* gibibyte, definition of: cmp Options. (line 87) 5060* gigabyte, definition of: cmp Options. (line 84) 5061* hd capability: diff Options. (line 189) 5062* headings: Sections. (line 6) 5063* hunks: Hunks. (line 6) 5064* hunks for diff3: diff3 Hunks. (line 6) 5065* if-then-else output format: If-then-else. (line 6) 5066* ifdef output format: If-then-else. (line 6) 5067* imperfect patch application: Imperfect. (line 6) 5068* incomplete line merging: Merging Incomplete Lines. 5069 (line 6) 5070* incomplete lines: Incomplete Lines. (line 6) 5071* inexact patches: Inexact. (line 6) 5072* inhibit messages from patch: More or Fewer Messages. 5073 (line 6) 5074* interactive merging: Interactive Merging. (line 6) 5075* introduction: Comparison. (line 6) 5076* intuiting file names from patches: Multiple Patches. (line 6) 5077* invoking cmp: Invoking cmp. (line 6) 5078* invoking diff: Invoking diff. (line 6) 5079* invoking diff3: Invoking diff3. (line 6) 5080* invoking patch: Invoking patch. (line 6) 5081* invoking sdiff: Invoking sdiff. (line 6) 5082* keyboard input to patch: patch and Keyboard Input. 5083 (line 6) 5084* kibibyte, definition of: cmp Options. (line 75) 5085* kilobyte, definition of: cmp Options. (line 71) 5086* LC_COLLATE: Comparing Directories. 5087 (line 6) 5088* LC_NUMERIC: Line Group Formats. (line 143) 5089* LC_TIME: Detailed Context. (line 12) 5090* line formats: Line Formats. (line 6) 5091* line group formats: Line Group Formats. (line 6) 5092* ln capability: diff Options. (line 194) 5093* mebibyte, definition of: cmp Options. (line 82) 5094* megabyte, definition of: cmp Options. (line 79) 5095* merge commands: Merge Commands. (line 6) 5096* merged diff3 format: Bypassing ed. (line 6) 5097* merged output format: If-then-else. (line 6) 5098* merging from a common ancestor: diff3 Merging. (line 6) 5099* merging interactively: Merge Commands. (line 6) 5100* messages from patch: patch Messages. (line 6) 5101* multibyte characters: Internationalization. 5102 (line 6) 5103* multiple patches: Multiple Patches. (line 6) 5104* newline treatment by diff: Incomplete Lines. (line 6) 5105* none color option: diff Options. (line 40) 5106* normal output format: Normal. (line 6) 5107* options for cmp: cmp Options. (line 6) 5108* options for diff: diff Options. (line 6) 5109* options for diff3: diff3 Options. (line 6) 5110* options for patch: patch Options. (line 6) 5111* options for sdiff: sdiff Options. (line 6) 5112* output formats: Output Formats. (line 6) 5113* overlap: diff3 Merging. (line 26) 5114* overlapping change, selection of: Which Changes. (line 6) 5115* overview of diff and patch: Overview. (line 6) 5116* paginating diff output: Pagination. (line 6) 5117* patch consumer tips: Tips for Patch Consumers. 5118 (line 6) 5119* patch input format: patch Input. (line 6) 5120* patch invocation: Invoking patch. (line 6) 5121* patch messages and questions: patch Messages. (line 6) 5122* patch options: patch Options. (line 6) 5123* patch producer tips: Tips for Patch Producers. 5124 (line 6) 5125* patch, common mistakes: Avoiding Common Mistakes. 5126 (line 6) 5127* patches, shrinking: Generating Smaller Patches. 5128 (line 6) 5129* patching directories: patch Directories. (line 6) 5130* PATCH_GET: Revision Control. (line 13) 5131* PATCH_VERSION_CONTROL: Backup Names. (line 21) 5132* pebibyte, definition of: cmp Options. (line 97) 5133* performance of diff: diff Performance. (line 6) 5134* petabyte, definition of: cmp Options. (line 94) 5135* POSIX: patch and POSIX. (line 6) 5136* POSIX <1>: Standards conformance. 5137 (line 6) 5138* POSIXLY_CORRECT: patch and POSIX. (line 6) 5139* POSIXLY_CORRECT <1>: Standards conformance. 5140 (line 6) 5141* projects for directories: Shortcomings. (line 6) 5142* quoting style: patch Quoting Style. (line 6) 5143* QUOTING_STYLE: patch Quoting Style. (line 26) 5144* RCS: Revision Control. (line 6) 5145* RCS script output format: RCS. (line 6) 5146* regular expression matching headings: Specified Headings. (line 6) 5147* regular expression suppression: Specified Lines. (line 6) 5148* reject file names: Reject Names. (line 6) 5149* removing empty files: Creating and Removing. 5150 (line 6) 5151* reporting bugs: Bugs. (line 6) 5152* reversed patches: Reversed Patches. (line 6) 5153* revision control: Revision Control. (line 6) 5154* sample input for diff: Sample diff Input. (line 6) 5155* sample input for diff3: Sample diff3 Input. (line 6) 5156* SCCS: Revision Control. (line 6) 5157* script output formats: Scripts. (line 6) 5158* sdiff invocation: Invoking sdiff. (line 6) 5159* sdiff options: sdiff Options. (line 6) 5160* sdiff output format: sdiff Option Summary. 5161 (line 6) 5162* section headings: Sections. (line 6) 5163* side by side: Side by Side. (line 6) 5164* side by side format: Side by Side Format. (line 6) 5165* SIMPLE_BACKUP_SUFFIX: Backup Names. (line 12) 5166* special files: Special Files. (line 6) 5167* specified headings: Specified Headings. (line 6) 5168* summarizing which files differ: Brief. (line 6) 5169* System V diff3 compatibility: Saving the Changed File. 5170 (line 6) 5171* tab and blank difference suppression: White Space. (line 6) 5172* tab stop alignment: Tabs. (line 6) 5173* tebibyte, definition of: cmp Options. (line 92) 5174* terabyte, definition of: cmp Options. (line 89) 5175* terminal, using color iff: diff Options. (line 42) 5176* testing patch: Dry Runs. (line 6) 5177* text versus binary diff: Binary. (line 6) 5178* timestamp format, context diffs: Detailed Context. (line 12) 5179* timestamp format, unified diffs: Detailed Unified. (line 12) 5180* timestamps on patched files: Patching Timestamps. (line 6) 5181* traditional patch: patch and Tradition. (line 6) 5182* trailing blanks: Trailing Blanks. (line 6) 5183* two-column output: Side by Side. (line 6) 5184* unified output format: Unified Format. (line 6) 5185* unmerged change: Which Changes. (line 6) 5186* varying-width characters: Internationalization. 5187 (line 6) 5188* verbose messages from patch: More or Fewer Messages. 5189 (line 6) 5190* version control: Revision Control. (line 6) 5191* VERSION_CONTROL: Revision Control. (line 22) 5192* VERSION_CONTROL <1>: Backup Names. (line 21) 5193* white space in patches: Changed White Space. (line 6) 5194* yottabyte, definition of: cmp Options. (line 110) 5195* zettabyte, definition of: cmp Options. (line 104) 5196 5197 5198 5199Tag Table: 5200Node: Top1431 5201Node: Overview3644 5202Node: Comparison7398 5203Node: Hunks10340 5204Node: White Space11781 5205Node: Blank Lines13620 5206Node: Specified Lines14609 5207Node: Case Folding15735 5208Node: Brief16152 5209Node: Binary17475 5210Node: Output Formats21272 5211Node: Sample diff Input21997 5212Node: Context23496 5213Node: Context Format25073 5214Node: Example Context25865 5215Node: Less Context27372 5216Node: Detailed Context28561 5217Node: Unified Format30756 5218Node: Example Unified31553 5219Node: Detailed Unified32591 5220Node: Sections34231 5221Node: Specified Headings34990 5222Node: C Function Headings36539 5223Node: Alternate Names37385 5224Node: Side by Side38298 5225Node: Side by Side Format40448 5226Node: Example Side by Side41350 5227Node: Normal42690 5228Node: Example Normal43691 5229Node: Detailed Normal44427 5230Node: Scripts46166 5231Node: ed Scripts46571 5232Node: Example ed47777 5233Node: Detailed ed48227 5234Node: Forward ed49986 5235Node: RCS50762 5236Node: If-then-else51978 5237Node: Line Group Formats53656 5238Node: Line Formats59537 5239Node: Example If-then-else62806 5240Node: Detailed If-then-else63885 5241Node: Incomplete Lines65770 5242Node: Comparing Directories67406 5243Node: Adjusting Output71698 5244Node: Tabs72205 5245Node: Trailing Blanks73819 5246Node: Pagination75044 5247Node: diff Performance75512 5248Node: Comparing Three Files78601 5249Node: Sample diff3 Input79479 5250Node: Example diff3 Normal80427 5251Node: Detailed diff3 Normal81487 5252Node: diff3 Hunks83275 5253Node: diff3 Merging84541 5254Node: Which Changes86786 5255Node: Marking Conflicts88186 5256Node: Bypassing ed90641 5257Node: Merging Incomplete Lines91984 5258Node: Saving the Changed File92710 5259Node: Interactive Merging93326 5260Node: sdiff Option Summary94035 5261Node: Merge Commands95238 5262Node: Merging with patch96527 5263Node: patch Input98894 5264Node: Revision Control99576 5265Node: Imperfect100746 5266Node: Changed White Space101895 5267Node: Reversed Patches102692 5268Node: Inexact104156 5269Node: Dry Runs107712 5270Node: Creating and Removing108576 5271Node: Patching Timestamps109625 5272Node: Multiple Patches111812 5273Node: patch Directories114473 5274Node: Backups116097 5275Node: Backup Names117161 5276Ref: Backup Names-Footnote-1120116 5277Node: Reject Names120243 5278Node: patch Messages120832 5279Node: More or Fewer Messages121892 5280Node: patch and Keyboard Input122523 5281Node: patch Quoting Style123552 5282Node: patch and POSIX124698 5283Node: patch and Tradition125537 5284Node: Making Patches128958 5285Node: Tips for Patch Producers129784 5286Node: Tips for Patch Consumers131039 5287Node: Avoiding Common Mistakes131676 5288Node: Generating Smaller Patches134201 5289Node: Invoking cmp135960 5290Node: cmp Options137510 5291Node: Invoking diff141154 5292Node: diff Options142773 5293Node: Invoking diff3152622 5294Node: diff3 Options153260 5295Node: Invoking patch156293 5296Node: patch Options157501 5297Node: Invoking sdiff162721 5298Node: sdiff Options163863 5299Node: Standards conformance166835 5300Node: Projects168581 5301Node: Shortcomings169293 5302Node: Internationalization170393 5303Node: Changing Structure171559 5304Node: Special Files172662 5305Node: Unusual File Names173773 5306Node: Timestamp Order174411 5307Node: Ignoring Changes175047 5308Node: Speedups175816 5309Node: Bugs176278 5310Node: Copying This Manual177131 5311Node: Translations202252 5312Node: Index202624 5313 5314End Tag Table 5315