1 /* filesys.c -- filesystem specific functions. 2 $Id: filesys.c,v 1.3 2000/02/09 02:18:39 espie Exp $ 3 4 Copyright (C) 1993, 97, 98 Free Software Foundation, Inc. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 20 Written by Brian Fox (bfox@ai.mit.edu). */ 21 22 #include "info.h" 23 24 #include "tilde.h" 25 #include "filesys.h" 26 27 /* Local to this file. */ 28 static char *info_file_in_path (), *lookup_info_filename (); 29 static char *info_absolute_file (); 30 static void remember_info_filename (), maybe_initialize_infopath (); 31 32 typedef struct 33 { 34 char *suffix; 35 char *decompressor; 36 } COMPRESSION_ALIST; 37 38 static char *info_suffixes[] = { 39 ".info", 40 "-info", 41 "/index", 42 ".inf", /* 8+3 file on filesystem which supports long file names */ 43 #ifdef __MSDOS__ 44 /* 8+3 file names strike again... */ 45 ".in", /* for .inz, .igz etc. */ 46 ".i", 47 #endif 48 "", 49 NULL 50 }; 51 52 static COMPRESSION_ALIST compress_suffixes[] = { 53 { ".gz", "gunzip" }, 54 { ".bz2", "bunzip2" }, 55 { ".z", "gunzip" }, 56 { ".Z", "uncompress" }, 57 { ".Y", "unyabba" }, 58 #ifdef __MSDOS__ 59 { "gz", "gunzip" }, 60 { "z", "gunzip" }, 61 #endif 62 { (char *)NULL, (char *)NULL } 63 }; 64 65 /* The path on which we look for info files. You can initialize this 66 from the environment variable INFOPATH if there is one, or you can 67 call info_add_path () to add paths to the beginning or end of it. 68 You can call zap_infopath () to make the path go away. */ 69 char *infopath = (char *)NULL; 70 static int infopath_size = 0; 71 72 /* Expand the filename in PARTIAL to make a real name for this operating 73 system. This looks in INFO_PATHS in order to find the correct file. 74 If it can't find the file, it returns NULL. */ 75 static char *local_temp_filename = (char *)NULL; 76 static int local_temp_filename_size = 0; 77 78 char * 79 info_find_fullpath (partial) 80 char *partial; 81 { 82 int initial_character; 83 char *temp; 84 85 filesys_error_number = 0; 86 87 maybe_initialize_infopath (); 88 89 if (partial && (initial_character = *partial)) 90 { 91 char *expansion; 92 93 expansion = lookup_info_filename (partial); 94 95 if (expansion) 96 return (expansion); 97 98 /* If we have the full path to this file, we still may have to add 99 various extensions to it. I guess we have to stat this file 100 after all. */ 101 if (IS_ABSOLUTE (partial)) 102 temp = info_absolute_file (partial); 103 else if (initial_character == '~') 104 { 105 expansion = tilde_expand_word (partial); 106 if (IS_ABSOLUTE (expansion)) 107 { 108 temp = info_absolute_file (expansion); 109 free (expansion); 110 } 111 else 112 temp = expansion; 113 } 114 else if (initial_character == '.' && 115 (IS_SLASH (partial[1]) || 116 (partial[1] == '.' && IS_SLASH (partial[2])))) 117 { 118 if (local_temp_filename_size < 1024) 119 local_temp_filename = (char *)xrealloc 120 (local_temp_filename, (local_temp_filename_size = 1024)); 121 #if defined (HAVE_GETCWD) 122 if (!getcwd (local_temp_filename, local_temp_filename_size)) 123 #else /* !HAVE_GETCWD */ 124 if (!getwd (local_temp_filename)) 125 #endif /* !HAVE_GETCWD */ 126 { 127 filesys_error_number = errno; 128 return (partial); 129 } 130 131 strcat (local_temp_filename, "/"); 132 strcat (local_temp_filename, partial); 133 temp = info_absolute_file (local_temp_filename); /* try extensions */ 134 if (!temp) 135 partial = local_temp_filename; 136 } 137 else 138 temp = info_file_in_path (partial, infopath); 139 140 if (temp) 141 { 142 remember_info_filename (partial, temp); 143 if (strlen (temp) > local_temp_filename_size) 144 local_temp_filename = (char *) xrealloc 145 (local_temp_filename, 146 (local_temp_filename_size = (50 + strlen (temp)))); 147 strcpy (local_temp_filename, temp); 148 free (temp); 149 return (local_temp_filename); 150 } 151 } 152 return (partial); 153 } 154 155 /* Scan the list of directories in PATH looking for FILENAME. If we find 156 one that is a regular file, return it as a new string. Otherwise, return 157 a NULL pointer. */ 158 static char * 159 info_file_in_path (filename, path) 160 char *filename, *path; 161 { 162 struct stat finfo; 163 char *temp_dirname; 164 int statable, dirname_index; 165 166 dirname_index = 0; 167 168 while ((temp_dirname = extract_colon_unit (path, &dirname_index))) 169 { 170 register int i, pre_suffix_length; 171 char *temp; 172 173 /* Expand a leading tilde if one is present. */ 174 if (*temp_dirname == '~') 175 { 176 char *expanded_dirname; 177 178 expanded_dirname = tilde_expand_word (temp_dirname); 179 free (temp_dirname); 180 temp_dirname = expanded_dirname; 181 } 182 183 temp = (char *)xmalloc (30 + strlen (temp_dirname) + strlen (filename)); 184 strcpy (temp, temp_dirname); 185 if (!IS_SLASH (temp[(strlen (temp)) - 1])) 186 strcat (temp, "/"); 187 strcat (temp, filename); 188 189 pre_suffix_length = strlen (temp); 190 191 free (temp_dirname); 192 193 for (i = 0; info_suffixes[i]; i++) 194 { 195 strcpy (temp + pre_suffix_length, info_suffixes[i]); 196 197 statable = (stat (temp, &finfo) == 0); 198 199 /* If we have found a regular file, then use that. Else, if we 200 have found a directory, look in that directory for this file. */ 201 if (statable) 202 { 203 if (S_ISREG (finfo.st_mode)) 204 { 205 return (temp); 206 } 207 else if (S_ISDIR (finfo.st_mode)) 208 { 209 char *newpath, *filename_only, *newtemp; 210 211 newpath = xstrdup (temp); 212 filename_only = filename_non_directory (filename); 213 newtemp = info_file_in_path (filename_only, newpath); 214 215 free (newpath); 216 if (newtemp) 217 { 218 free (temp); 219 return (newtemp); 220 } 221 } 222 } 223 else 224 { 225 /* Add various compression suffixes to the name to see if 226 the file is present in compressed format. */ 227 register int j, pre_compress_suffix_length; 228 229 pre_compress_suffix_length = strlen (temp); 230 231 for (j = 0; compress_suffixes[j].suffix; j++) 232 { 233 strcpy (temp + pre_compress_suffix_length, 234 compress_suffixes[j].suffix); 235 236 statable = (stat (temp, &finfo) == 0); 237 if (statable && (S_ISREG (finfo.st_mode))) 238 return (temp); 239 } 240 } 241 } 242 free (temp); 243 } 244 return ((char *)NULL); 245 } 246 247 /* Assume FNAME is an absolute file name, and check whether it is 248 a regular file. If it is, return it as a new string; otherwise 249 return a NULL pointer. We do it by taking the file name apart 250 into its directory and basename parts, and calling info_file_in_path.*/ 251 static char * 252 info_absolute_file (fname) 253 char *fname; 254 { 255 char *containing_dir = xstrdup (fname); 256 char *base = filename_non_directory (containing_dir); 257 258 if (base > containing_dir) 259 base[-1] = '\0'; 260 261 return info_file_in_path (filename_non_directory (fname), containing_dir); 262 } 263 264 /* Given a string containing units of information separated by 265 the PATH_SEP character, return the next one pointed to by 266 IDX, or NULL if there are no more. 267 Advance IDX to the character after the colon. */ 268 char * 269 extract_colon_unit (string, idx) 270 char *string; 271 int *idx; 272 { 273 register int i, start; 274 275 i = start = *idx; 276 if ((i >= strlen (string)) || !string) 277 return ((char *) NULL); 278 279 while (string[i] && string[i] != PATH_SEP[0]) 280 i++; 281 if (i == start) 282 { 283 return ((char *) NULL); 284 } 285 else 286 { 287 char *value; 288 289 value = (char *) xmalloc (1 + (i - start)); 290 strncpy (value, &string[start], (i - start)); 291 value[i - start] = '\0'; 292 if (string[i]) 293 ++i; 294 *idx = i; 295 return (value); 296 } 297 } 298 299 /* A structure which associates a filename with its expansion. */ 300 typedef struct { 301 char *filename; 302 char *expansion; 303 } FILENAME_LIST; 304 305 /* An array of remembered arguments and results. */ 306 static FILENAME_LIST **names_and_files = (FILENAME_LIST **)NULL; 307 static int names_and_files_index = 0; 308 static int names_and_files_slots = 0; 309 310 /* Find the result for having already called info_find_fullpath () with 311 FILENAME. */ 312 static char * 313 lookup_info_filename (filename) 314 char *filename; 315 { 316 if (filename && names_and_files) 317 { 318 register int i; 319 for (i = 0; names_and_files[i]; i++) 320 { 321 if (FILENAME_CMP (names_and_files[i]->filename, filename) == 0) 322 return (names_and_files[i]->expansion); 323 } 324 } 325 return (char *)NULL;; 326 } 327 328 /* Add a filename and its expansion to our list. */ 329 static void 330 remember_info_filename (filename, expansion) 331 char *filename, *expansion; 332 { 333 FILENAME_LIST *new; 334 335 if (names_and_files_index + 2 > names_and_files_slots) 336 { 337 int alloc_size; 338 names_and_files_slots += 10; 339 340 alloc_size = names_and_files_slots * sizeof (FILENAME_LIST *); 341 342 names_and_files = 343 (FILENAME_LIST **) xrealloc (names_and_files, alloc_size); 344 } 345 346 new = (FILENAME_LIST *)xmalloc (sizeof (FILENAME_LIST)); 347 new->filename = xstrdup (filename); 348 new->expansion = expansion ? xstrdup (expansion) : (char *)NULL; 349 350 names_and_files[names_and_files_index++] = new; 351 names_and_files[names_and_files_index] = (FILENAME_LIST *)NULL; 352 } 353 354 static void 355 maybe_initialize_infopath () 356 { 357 if (!infopath_size) 358 { 359 infopath = (char *) 360 xmalloc (infopath_size = (1 + strlen (DEFAULT_INFOPATH))); 361 362 strcpy (infopath, DEFAULT_INFOPATH); 363 } 364 } 365 366 /* Add PATH to the list of paths found in INFOPATH. 2nd argument says 367 whether to put PATH at the front or end of INFOPATH. */ 368 void 369 info_add_path (path, where) 370 char *path; 371 int where; 372 { 373 int len; 374 375 if (!infopath) 376 { 377 infopath = (char *)xmalloc (infopath_size = 200 + strlen (path)); 378 infopath[0] = '\0'; 379 } 380 381 len = strlen (path) + strlen (infopath); 382 383 if (len + 2 >= infopath_size) 384 infopath = (char *)xrealloc (infopath, (infopath_size += (2 * len) + 2)); 385 386 if (!*infopath) 387 strcpy (infopath, path); 388 else if (where == INFOPATH_APPEND) 389 { 390 strcat (infopath, PATH_SEP); 391 strcat (infopath, path); 392 } 393 else if (where == INFOPATH_PREPEND) 394 { 395 char *temp = xstrdup (infopath); 396 strcpy (infopath, path); 397 strcat (infopath, PATH_SEP); 398 strcat (infopath, temp); 399 free (temp); 400 } 401 } 402 403 /* Make INFOPATH have absolutely nothing in it. */ 404 void 405 zap_infopath () 406 { 407 if (infopath) 408 free (infopath); 409 410 infopath = (char *)NULL; 411 infopath_size = 0; 412 } 413 414 /* Given a chunk of text and its length, convert all CRLF pairs at every 415 end-of-line into a single Newline character. Return the length of 416 produced text. 417 418 This is required because the rest of code is too entrenched in having 419 a single newline at each EOL; in particular, searching for various 420 Info headers and cookies can become extremely tricky if that assumption 421 breaks. 422 423 FIXME: this could also support Mac-style text files with a single CR 424 at the EOL, but what about random CR characters in non-Mac files? Can 425 we afford converting them into newlines as well? Maybe implement some 426 heuristics here, like in Emacs 20. 427 428 FIXME: is it a good idea to show the EOL type on the modeline? */ 429 long 430 convert_eols (text, textlen) 431 char *text; 432 long textlen; 433 { 434 register char *s = text; 435 register char *d = text; 436 437 while (textlen--) 438 { 439 if (*s == '\r' && textlen && s[1] == '\n') 440 { 441 s++; 442 textlen--; 443 } 444 *d++ = *s++; 445 } 446 447 return (long)(d - text); 448 } 449 450 /* Read the contents of PATHNAME, returning a buffer with the contents of 451 that file in it, and returning the size of that buffer in FILESIZE. 452 FINFO is a stat struct which has already been filled in by the caller. 453 If the file turns out to be compressed, set IS_COMPRESSED to non-zero. 454 If the file cannot be read, return a NULL pointer. */ 455 char * 456 filesys_read_info_file (pathname, filesize, finfo, is_compressed) 457 char *pathname; 458 long *filesize; 459 struct stat *finfo; 460 int *is_compressed; 461 { 462 long st_size; 463 464 *filesize = filesys_error_number = 0; 465 466 if (compressed_filename_p (pathname)) 467 { 468 *is_compressed = 1; 469 return (filesys_read_compressed (pathname, filesize, finfo)); 470 } 471 else 472 { 473 int descriptor; 474 char *contents; 475 476 *is_compressed = 0; 477 descriptor = open (pathname, O_RDONLY | O_BINARY, 0666); 478 479 /* If the file couldn't be opened, give up. */ 480 if (descriptor < 0) 481 { 482 filesys_error_number = errno; 483 return ((char *)NULL); 484 } 485 486 /* Try to read the contents of this file. */ 487 st_size = (long) finfo->st_size; 488 contents = (char *)xmalloc (1 + st_size); 489 if ((read (descriptor, contents, st_size)) != st_size) 490 { 491 filesys_error_number = errno; 492 close (descriptor); 493 free (contents); 494 return ((char *)NULL); 495 } 496 497 close (descriptor); 498 499 /* Convert any DOS-style CRLF EOLs into Unix-style NL. 500 Seems like a good idea to have even on Unix, in case the Info 501 files are coming from some Windows system across a network. */ 502 *filesize = convert_eols (contents, st_size); 503 504 /* EOL conversion can shrink the text quite a bit. We don't 505 want to waste storage. */ 506 if (*filesize < st_size) 507 contents = (char *)xrealloc (contents, 1 + *filesize); 508 509 return (contents); 510 } 511 } 512 513 /* Typically, pipe buffers are 4k. */ 514 #define BASIC_PIPE_BUFFER (4 * 1024) 515 516 /* We use some large multiple of that. */ 517 #define FILESYS_PIPE_BUFFER_SIZE (16 * BASIC_PIPE_BUFFER) 518 519 char * 520 filesys_read_compressed (pathname, filesize, finfo) 521 char *pathname; 522 long *filesize; 523 struct stat *finfo; 524 { 525 FILE *stream; 526 char *command, *decompressor; 527 char *contents = (char *)NULL; 528 529 *filesize = filesys_error_number = 0; 530 531 decompressor = filesys_decompressor_for_file (pathname); 532 533 if (!decompressor) 534 return ((char *)NULL); 535 536 command = (char *)xmalloc (15 + strlen (pathname) + strlen (decompressor)); 537 /* Explicit .exe suffix makes the diagnostics of `popen' 538 better on systems where COMMAND.COM is the stock shell. */ 539 sprintf (command, "%s%s < %s", 540 decompressor, STRIP_DOT_EXE ? ".exe" : "", pathname); 541 542 #if !defined (BUILDING_LIBRARY) 543 if (info_windows_initialized_p) 544 { 545 char *temp; 546 547 temp = (char *)xmalloc (5 + strlen (command)); 548 sprintf (temp, "%s...", command); 549 message_in_echo_area ("%s", temp); 550 free (temp); 551 } 552 #endif /* !BUILDING_LIBRARY */ 553 554 stream = popen (command, FOPEN_RBIN); 555 free (command); 556 557 /* Read chunks from this file until there are none left to read. */ 558 if (stream) 559 { 560 int offset, size; 561 char *chunk; 562 563 offset = size = 0; 564 chunk = (char *)xmalloc (FILESYS_PIPE_BUFFER_SIZE); 565 566 while (1) 567 { 568 int bytes_read; 569 570 bytes_read = fread (chunk, 1, FILESYS_PIPE_BUFFER_SIZE, stream); 571 572 if (bytes_read + offset >= size) 573 contents = (char *)xrealloc 574 (contents, size += (2 * FILESYS_PIPE_BUFFER_SIZE)); 575 576 memcpy (contents + offset, chunk, bytes_read); 577 offset += bytes_read; 578 if (bytes_read != FILESYS_PIPE_BUFFER_SIZE) 579 break; 580 } 581 582 free (chunk); 583 if (pclose (stream) == -1) 584 { 585 if (contents) 586 free (contents); 587 contents = (char *)NULL; 588 filesys_error_number = errno; 589 } 590 else 591 { 592 *filesize = convert_eols (contents, offset); 593 contents = (char *)xrealloc (contents, 1 + *filesize); 594 } 595 } 596 else 597 { 598 filesys_error_number = errno; 599 } 600 601 #if !defined (BUILDING_LIBARARY) 602 if (info_windows_initialized_p) 603 unmessage_in_echo_area (); 604 #endif /* !BUILDING_LIBRARY */ 605 return (contents); 606 } 607 608 /* Return non-zero if FILENAME belongs to a compressed file. */ 609 int 610 compressed_filename_p (filename) 611 char *filename; 612 { 613 char *decompressor; 614 615 /* Find the final extension of this filename, and see if it matches one 616 of our known ones. */ 617 decompressor = filesys_decompressor_for_file (filename); 618 619 if (decompressor) 620 return (1); 621 else 622 return (0); 623 } 624 625 /* Return the command string that would be used to decompress FILENAME. */ 626 char * 627 filesys_decompressor_for_file (filename) 628 char *filename; 629 { 630 register int i; 631 char *extension = (char *)NULL; 632 633 /* Find the final extension of FILENAME, and see if it appears in our 634 list of known compression extensions. */ 635 for (i = strlen (filename) - 1; i > 0; i--) 636 if (filename[i] == '.') 637 { 638 extension = filename + i; 639 break; 640 } 641 642 if (!extension) 643 return ((char *)NULL); 644 645 for (i = 0; compress_suffixes[i].suffix; i++) 646 if (FILENAME_CMP (extension, compress_suffixes[i].suffix) == 0) 647 return (compress_suffixes[i].decompressor); 648 649 #if defined (__MSDOS__) 650 /* If no other suffix matched, allow any extension which ends 651 with `z' to be decompressed by gunzip. Due to limited 8+3 DOS 652 file namespace, we can expect many such cases, and supporting 653 every weird suffix thus produced would be a pain. */ 654 if (extension[strlen (extension) - 1] == 'z' || 655 extension[strlen (extension) - 1] == 'Z') 656 return "gunzip"; 657 #endif 658 659 return ((char *)NULL); 660 } 661 662 /* The number of the most recent file system error. */ 663 int filesys_error_number = 0; 664 665 /* A function which returns a pointer to a static buffer containing 666 an error message for FILENAME and ERROR_NUM. */ 667 static char *errmsg_buf = (char *)NULL; 668 static int errmsg_buf_size = 0; 669 670 char * 671 filesys_error_string (filename, error_num) 672 char *filename; 673 int error_num; 674 { 675 int len; 676 char *result; 677 678 if (error_num == 0) 679 return ((char *)NULL); 680 681 result = strerror (error_num); 682 683 len = 4 + strlen (filename) + strlen (result); 684 if (len >= errmsg_buf_size) 685 errmsg_buf = (char *)xrealloc (errmsg_buf, (errmsg_buf_size = 2 + len)); 686 687 sprintf (errmsg_buf, "%s: %s", filename, result); 688 return (errmsg_buf); 689 } 690 691 692 /* Check for FILENAME eq "dir" first, then all the compression 693 suffixes. */ 694 695 int 696 is_dir_name (filename) 697 char *filename; 698 { 699 unsigned i; 700 if (strcasecmp (filename, "dir") == 0) 701 return 1; 702 703 for (i = 0; compress_suffixes[i].suffix; i++) 704 { 705 char dir_compressed[50]; /* can be short */ 706 strcpy (dir_compressed, "dir"); 707 strcat (dir_compressed, compress_suffixes[i].suffix); 708 if (strcasecmp (filename, dir_compressed) == 0) 709 return 1; 710 } 711 712 return 0; 713 } 714