xref: /netbsd-src/bin/pax/pax.1 (revision c34236556bea94afcaca1782d7d228301edc3ea0)
1.\"    $NetBSD: pax.1,v 1.68 2016/08/12 01:52:22 sevan Exp $
2.\"
3.\" Copyright (c) 1992 Keith Muller.
4.\" Copyright (c) 1992, 1993
5.\"	The Regents of the University of California.  All rights reserved.
6.\"
7.\" This code is derived from software contributed to Berkeley by
8.\" Keith Muller of the University of California, San Diego.
9.\"
10.\" Redistribution and use in source and binary forms, with or without
11.\" modification, are permitted provided that the following conditions
12.\" are met:
13.\" 1. Redistributions of source code must retain the above copyright
14.\"    notice, this list of conditions and the following disclaimer.
15.\" 2. Redistributions in binary form must reproduce the above copyright
16.\"    notice, this list of conditions and the following disclaimer in the
17.\"    documentation and/or other materials provided with the distribution.
18.\" 3. Neither the name of the University nor the names of its contributors
19.\"    may be used to endorse or promote products derived from this software
20.\"    without specific prior written permission.
21.\"
22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32.\" SUCH DAMAGE.
33.\"
34.\"	@(#)pax.1	8.4 (Berkeley) 4/18/94
35.\"
36.Dd August 12, 2016
37.Dt PAX 1
38.Os
39.Sh NAME
40.Nm pax
41.Nd read and write file archives and copy directory hierarchies
42.Sh SYNOPSIS
43.Nm
44.Op Fl 0cdjnOVvz
45.Op Fl E Ar limit
46.Op Fl f Ar archive
47.Op Fl N Ar dbdir
48.Op Fl s Ar replstr
49.Ar ...\&
50.Op Fl U Ar user
51.Ar ...\&
52.Op Fl G Ar group
53.Ar ...\&
54.Oo
55.Fl T
56.Sm off
57.Op Ar from_date
58.Oo , Ar to_date Oc
59.Sm on
60.Oc
61.Ar ...\&
62.Op Ar pattern ...\&
63.Nm
64.Fl r
65.Op Fl AcDdijknOuVvYZz
66.Op Fl E Ar limit
67.Op Fl f Ar archive
68.Op Fl N Ar dbdir
69.Op Fl o Ar options
70.Ar ...\&
71.Op Fl p Ar string
72.Ar ...\&
73.Op Fl s Ar replstr
74.Ar ...\&
75.Op Fl U Ar user
76.Ar ...\&
77.Op Fl G Ar group
78.Ar ...\&
79.Oo
80.Fl T
81.Sm off
82.Op Ar from_date
83.Oo , Ar to_date Oc
84.Sm on
85.Oc
86.Ar ...\&
87.Op Ar pattern ...\&
88.Nm
89.Fl w
90.Op Fl AdHijLMOPtuVvXz
91.Op Fl b Ar blocksize
92.Oo
93.Op Fl a
94.Op Fl f Ar archive
95.Oc
96.Op Fl x Ar format
97.Op Fl B Ar bytes
98.Op Fl N Ar dbdir
99.Op Fl o Ar options
100.Ar ...\&
101.Op Fl s Ar replstr
102.Ar ...\&
103.Op Fl U Ar user
104.Ar ...\&
105.Op Fl G Ar group
106.Ar ...\&
107.Oo
108.Fl T
109.Sm off
110.Op Ar from_date
111.Oo , Ar to_date Oc
112.Oo /[ Cm c ] [ Cm m ] Oc
113.Sm on
114.Oc
115.Ar ...\&
116.Op Ar file ...\&
117.Nm
118.Fl r
119.Fl w
120.Op Fl ADdHijkLlMnOPtuVvXYZz
121.Op Fl N Ar dbdir
122.Op Fl p Ar string
123.Ar ...\&
124.Op Fl s Ar replstr
125.Ar ...\&
126.Op Fl U Ar user
127.Ar ...\&
128.Op Fl G Ar group
129.Ar ...\&
130.Oo
131.Fl T
132.Sm off
133.Op Ar from_date
134.Oo , Ar to_date Oc
135.Oo /[ Cm c ] [ Cm m ] Oc
136.Sm on
137.Oc
138.Ar ...\&
139.Op Ar file ...\&
140.Ar directory
141.Sh DESCRIPTION
142.Nm
143will read, write, and list the members of an archive file,
144and will copy directory hierarchies.
145If the archive file is of the form:
146.Ar [[user@]host:]file
147then the archive will be processed using
148.Xr rmt 8 .
149.Pp
150.Nm
151operation is independent of the specific archive format,
152and supports a wide variety of different archive formats.
153A list of supported archive formats can be found under the description of the
154.Fl x
155option.
156.Pp
157The presence of the
158.Fl r
159and the
160.Fl w
161options specifies which of the following functional modes
162.Nm
163will operate under:
164.Em list , read , write ,
165and
166.Em copy .
167.Bl -tag -width 6n
168.It Aq none
169.Em List .
170.Nm
171will write to
172.Dv standard output
173a table of contents of the members of the archive file read from
174.Dv standard input ,
175whose pathnames match the specified
176.Ar patterns .
177The table of contents contains one filename per line
178and is written using single line buffering.
179.It Fl r
180.Em Read .
181.Nm
182extracts the members of the archive file read from the
183.Dv standard input ,
184with pathnames matching the specified
185.Ar patterns .
186The archive format and blocking is automatically determined on input.
187When an extracted file is a directory, the entire file hierarchy
188rooted at that directory is extracted.
189All extracted files are created relative to the current file hierarchy.
190The setting of ownership, access and modification times, and file mode of
191the extracted files are discussed in more detail under the
192.Fl p
193option.
194.It Fl w
195.Em Write .
196.Nm
197writes an archive containing the
198.Ar file
199operands to
200.Dv standard output
201using the specified archive format.
202When no
203.Ar file
204operands are specified, a list of files to copy with one per line is read from
205.Dv standard input .
206When a
207.Ar file
208operand is also a directory, the entire file hierarchy rooted
209at that directory will be included.
210.It Fl r Fl w
211.Em Copy .
212.Nm
213copies the
214.Ar file
215operands to the destination
216.Ar directory .
217When no
218.Ar file
219operands are specified, a list of files to copy with one per line is read from
220the
221.Dv standard input .
222When a
223.Ar file
224operand is also a directory the entire file
225hierarchy rooted at that directory will be included.
226The effect of the
227.Em copy
228is as if the copied files were written to an archive file and then
229subsequently extracted, except that there may be hard links between
230the original and the copied files (see the
231.Fl l
232option below).
233.Pp
234.Em Warning :
235The destination
236.Ar directory
237must not be one of the
238.Ar file
239operands or a member of a file hierarchy rooted at one of the
240.Ar file
241operands.
242The result of a
243.Em copy
244under these conditions is unpredictable.
245.El
246.Pp
247While processing a damaged archive during a
248.Em read
249or
250.Em list
251operation,
252.Nm
253will attempt to recover from media defects and will search through the archive
254to locate and process the largest number of archive members possible (see the
255.Fl E
256option for more details on error handling).
257.Sh OPERANDS
258The
259.Ar directory
260operand specifies a destination directory pathname.
261If the
262.Ar directory
263operand does not exist, or it is not writable by the user,
264or it is not of type directory,
265.Nm
266will exit with a non-zero exit status.
267.Pp
268The
269.Ar pattern
270operand is used to select one or more pathnames of archive members.
271Archive members are selected using the pattern matching notation described
272by
273.Xr fnmatch 3 .
274When the
275.Ar pattern
276operand is not supplied, all members of the archive will be selected.
277When a
278.Ar pattern
279matches a directory, the entire file hierarchy rooted at that directory will
280be selected.
281When a
282.Ar pattern
283operand does not select at least one archive member,
284.Nm
285will write these
286.Ar pattern
287operands in a diagnostic message to
288.Dv standard error
289and then exit with a non-zero exit status.
290.Pp
291The
292.Ar file
293operand specifies the pathname of a file to be copied or archived.
294When a
295.Ar file
296operand does not select at least one archive member,
297.Nm
298will write these
299.Ar file
300operand pathnames in a diagnostic message to
301.Dv standard error
302and then exit with a non-zero exit status.
303.Sh OPTIONS
304The following options are supported:
305.Bl -tag -width 4n
306.It Fl r
307Read an archive file from
308.Dv standard input
309and extract the specified
310.Ar files .
311If any intermediate directories are needed in order to extract an archive
312member, these directories will be created as if
313.Xr mkdir 2
314was called with the bitwise inclusive
315.Dv OR
316of
317.Dv S_IRWXU , S_IRWXG ,
318and
319.Dv S_IRWXO
320as the mode argument.
321When the selected archive format supports the specification of linked
322files and these files cannot be linked while the archive is being extracted,
323.Nm
324will write a diagnostic message to
325.Dv standard error
326and exit with a non-zero exit status at the completion of operation.
327.It Fl w
328Write files to the
329.Dv standard output
330in the specified archive format.
331When no
332.Ar file
333operands are specified,
334.Dv standard input
335is read for a list of pathnames with one per line without any leading or
336trailing
337.Aq blanks .
338.It Fl a
339Append
340.Ar files
341to the end of an archive that was previously written.
342If an archive format is not specified with a
343.Fl x
344option, the format currently being used in the archive will be selected.
345Any attempt to append to an archive in a format different from the
346format already used in the archive will cause
347.Nm
348to exit immediately
349with a non-zero exit status.
350The blocking size used in the archive volume where writing starts
351will continue to be used for the remainder of that archive volume.
352.Pp
353.Em Warning :
354Many storage devices are not able to support the operations necessary
355to perform an append operation.
356Any attempt to append to an archive stored on such a device may damage the
357archive or have other unpredictable results.
358Tape drives in particular are more likely to not support an append operation.
359An archive stored in a regular file system file or on a disk device will
360usually support an append operation.
361.It Fl b Ar blocksize
362When
363.Em writing
364an archive,
365block the output at a positive decimal integer number of
366bytes per write to the archive file.
367The
368.Ar blocksize
369must be a multiple of 512 bytes with a maximum of 32256 bytes.
370A
371.Ar blocksize
372can end with
373.Li k
374or
375.Li b
376to specify multiplication by 1024 (1K) or 512, respectively.
377A pair of
378.Ar blocksizes
379can be separated by
380.Li x
381to indicate a product.
382A specific archive device may impose additional restrictions on the size
383of blocking it will support.
384When blocking is not specified, the default
385.Ar blocksize
386is dependent on the specific archive format being used (see the
387.Fl x
388option).
389.It Fl c
390Match all file or archive members
391.Em except
392those specified by the
393.Ar pattern
394and
395.Ar file
396operands.
397.It Fl d
398Cause files of type directory being copied or archived, or archive members of
399type directory being extracted, to match only the directory file or archive
400member and not the file hierarchy rooted at the directory.
401.It Fl f Ar archive
402Specify
403.Ar archive
404as the pathname of the input or output archive, overriding the default
405.Dv standard input
406(for
407.Em list
408and
409.Em read )
410or
411.Dv standard output
412(for
413.Em write ) .
414A single archive may span multiple files and different archive devices.
415When required,
416.Nm
417will prompt for the pathname of the file or device of the next volume in the
418archive.
419.It Fl i
420Interactively rename files or archive members.
421For each archive member matching a
422.Ar pattern
423operand or each file matching a
424.Ar file
425operand,
426.Nm
427will prompt to
428.Pa /dev/tty
429giving the name of the file, its file mode and its modification time.
430.Nm
431will then read a line from
432.Pa /dev/tty .
433If this line is blank, the file or archive member is skipped.
434If this line consists of a single period, the
435file or archive member is processed with no modification to its name.
436Otherwise, its name is replaced with the contents of the line.
437.Nm
438will immediately exit with a non-zero exit status if
439.Aq Dv EOF
440is encountered when reading a response or if
441.Pa /dev/tty
442cannot be opened for reading and writing.
443.It Fl j
444Use
445.Xr bzip2 1
446for compression when reading or writing archive files.
447.It Fl k
448Do not overwrite existing files.
449.It Fl l
450Link files.
451(The letter ell).
452In the
453.Em copy
454mode
455.Fl ( r
456.Fl w ) ,
457hard links are made between the source and destination file hierarchies
458whenever possible.
459.It Fl n
460Select the first archive member that matches each
461.Ar pattern
462operand.
463No more than one archive member is matched for each
464.Ar pattern .
465When members of type directory are matched, the file hierarchy rooted at that
466directory is also matched (unless
467.Fl d
468is also specified).
469.It Fl o Ar options
470Information to modify the algorithm for extracting or writing archive files
471which is specific to the archive format specified by
472.Fl x .
473In general,
474.Ar options
475take the form:
476.Cm name=value
477.It Fl p Ar string
478Specify one or more file characteristic options (privileges).
479The
480.Ar string
481option-argument is a string specifying file characteristics to be retained or
482discarded on extraction.
483The string consists of the specification characters
484.Cm a , e ,
485.Cm m , o ,
486and
487.Cm p .
488Multiple characteristics can be concatenated within the same string
489and multiple
490.Fl p
491options can be specified.
492The meaning of the specification characters are as follows:
493.Bl -tag -width 2n
494.It Cm a
495Do not preserve file access times.
496By default, file access times are preserved whenever possible.
497.It Cm e
498.Sq Preserve everything ,
499the user ID, group ID, file mode bits,
500file access time, and file modification time.
501This is intended to be used by
502.Em root ,
503someone with all the appropriate privileges, in order to preserve all
504aspects of the files as they are recorded in the archive.
505The
506.Cm e
507flag is the sum of the
508.Cm o
509and
510.Cm p
511flags.
512.\" .It Cm f
513.\" Do not preserve file flags.
514.\" By default, file flags are preserved whenever possible.
515.It Cm m
516Do not preserve file modification times.
517By default, file modification times are preserved whenever possible.
518.It Cm o
519Preserve the user ID and group ID.
520.It Cm p
521.Sq Preserve
522the file mode bits.
523This is intended to be used by a
524.Em user
525with regular privileges who wants to preserve all aspects of the file other
526than the ownership.
527The file times are preserved by default, but two other flags are offered to
528disable this and use the time of extraction instead.
529.El
530.Pp
531In the preceding list,
532.Sq preserve
533indicates that an attribute stored in the archive is given to the
534extracted file, subject to the permissions of the invoking
535process.
536Otherwise the attribute of the extracted file is determined as
537part of the normal file creation action.
538If neither the
539.Cm e
540nor the
541.Cm o
542specification character is specified, or the user ID and group ID are not
543preserved for any reason,
544.Nm
545will not set the
546.Dv S_ISUID
547.Em ( setuid )
548and
549.Dv S_ISGID
550.Em ( setgid )
551bits of the file mode.
552If the preservation of any of these items fails for any reason,
553.Nm
554will write a diagnostic message to
555.Dv standard error .
556Failure to preserve these items will affect the final exit status,
557but will not cause the extracted file to be deleted.
558If the file characteristic letters in any of the string option-arguments are
559duplicated or conflict with each other, the one(s) given last will take
560precedence.
561For example, if
562.Dl Fl p Ar eme
563is specified, file modification times are still preserved.
564.It Fl s Ar replstr
565Modify the file or archive member names specified by the
566.Ar pattern
567or
568.Ar file
569operands according to the substitution expression
570.Ar replstr ,
571using the syntax of the
572.Xr ed 1
573utility regular expressions.
574The format of these regular expressions are:
575.Dl /old/new/[gp]
576As in
577.Xr ed 1 ,
578.Cm old
579is a basic regular expression and
580.Cm new
581can contain an ampersand (\*[Am]), \en (where n is a digit) back-references,
582or subexpression matching.
583The
584.Cm old
585string may also contain
586.Aq Dv newline
587characters.
588Any non-null character can be used as a delimiter (/ is shown here).
589Multiple
590.Fl s
591expressions can be specified.
592The expressions are applied in the order they are specified on the
593command line, terminating with the first successful substitution.
594The optional trailing
595.Cm g
596continues to apply the substitution expression to the pathname substring
597which starts with the first character following the end of the last successful
598substitution.
599The first unsuccessful substitution stops the operation of the
600.Cm g
601option.
602The optional trailing
603.Cm p
604will cause the final result of a successful substitution to be written to
605.Dv standard error
606in the following format:
607.Dl Ao "original pathname" Ac \*[Gt]\*[Gt] Ao "new pathname" Ac
608File or archive member names that substitute to the empty string
609are not selected and will be skipped.
610.It Fl t
611Reset the access times of any file or directory read or accessed by
612.Nm
613to be the same as they were before being read or accessed by
614.Nm ,
615if the user has the appropriate permissions required by
616.Xr utime 3 .
617.It Fl u
618Ignore files that are older (having a less recent file modification time)
619than a pre-existing file or archive member with the same name.
620During
621.Em read ,
622an archive member with the same name as a file in the file system will be
623extracted if the archive member is newer than the file.
624During
625.Em write ,
626a file system member with the same name as an archive member will be
627written to the archive if it is newer than the archive member.
628During
629.Em copy ,
630the file in the destination hierarchy is replaced by the file in the source
631hierarchy or by a link to the file in the source hierarchy if the file in
632the source hierarchy is newer.
633.It Fl v
634During a
635.Em list
636operation, produce a verbose table of contents using the format of the
637.Xr ls 1
638utility with the
639.Fl l
640option.
641For pathnames representing a hard link to a previous member of the archive,
642the output has the format:
643.Dl Ao "ls -l listing" Ac == Ao "link name" Ac
644Where
645.Aq "ls -l listing"
646is the output format specified by the
647.Xr ls 1
648utility when used with the
649.Fl l
650option.
651.Pp
652Otherwise for all the other operational modes
653.Em ( read , write ,
654and
655.Em copy ) ,
656pathnames are written and flushed to
657.Dv standard error
658without a trailing
659.Aq Dv newline
660as soon as processing begins on that file or
661archive member.
662The trailing
663.Aq Dv newline ,
664is not buffered, and is written only after the file has been read or written.
665.Pp
666A final summary of archive operations is printed after they have been
667completed.
668.It Fl x Ar format
669Specify the output archive format, with the default format being
670.Ar ustar .
671.Nm
672currently supports the following formats:
673.Bl -tag -width "sv4cpio"
674.It Ar cpio
675The extended cpio interchange format specified in the
676.St -p1003.2
677standard.
678The default blocksize for this format is 5120 bytes.
679Inode and device information about a file (used for detecting file hard links
680by this format) which may be truncated by this format is detected by
681.Nm
682and is repaired.
683.It Ar bcpio
684The old binary cpio format.
685The default blocksize for this format is 5120 bytes.
686This format is not very portable and should not be used when other formats
687are available.
688Inode and device information about a file (used for detecting file hard links
689by this format) which may be truncated by this format is detected by
690.Nm
691and is repaired.
692.It Ar sv4cpio
693The
694.At V.4
695cpio.
696The default blocksize for this format is 5120 bytes.
697Inode and device information about a file (used for detecting file hard links
698by this format) which may be truncated by this format is detected by
699.Nm
700and is repaired.
701.It Ar sv4crc
702The
703.At V.4
704cpio with file crc checksums.
705The default blocksize for this format is 5120 bytes.
706Inode and device information about a file (used for detecting file hard links
707by this format) which may be truncated by this format is detected by
708.Nm
709and is repaired.
710.It Ar tar
711The old
712.Bx
713tar format as found in
714.Bx 4.3 .
715The default blocksize for this format is 10240 bytes.
716Pathnames stored by this format must be 100 characters or less in length.
717Only
718.Em regular
719files,
720.Em  hard links , soft links ,
721and
722.Em  directories
723will be archived (other file types are not supported).
724For backward compatibility with even older tar formats, a
725.Fl o
726option can be used when writing an archive to omit the storage of directories.
727This option takes the form:
728.Dl Fl o Cm write_opt=nodir
729.It Ar ustar
730The extended tar interchange format specified in the
731.St -p1003.2
732standard.
733The default blocksize for this format is 10240 bytes.
734Pathnames stored by this format must be 250 characters or less in length.
735.El
736.Pp
737.Nm
738will detect and report any file that it is unable to store or extract
739as the result of any specific archive format restrictions.
740The individual archive formats may impose additional restrictions on use.
741Typical archive format restrictions include (but are not limited to):
742file pathname length, file size, link pathname length and the type of the file.
743.It Fl Fl gnu
744Recognize GNU tar extensions.
745.It Fl Fl timestamp Ar timestamp
746Store all modification times in the archive with the
747.Ar timestamp
748given instead of the actual modification time of the individual archive member
749so that repeatable builds are possible.
750The
751.Ar timestamp
752can be a
753.Pa pathname ,
754where the timestamps are derived from that file, a parseable date for
755.Xr parsedate 3
756(this option is not yet available in the tools build), or an integer value
757interpreted as the number of seconds from the Epoch.
758.It Fl Fl xz
759Use
760.Xr xz 1
761compression, when reading or writing archive files.
762.It Fl z
763Use
764.Xr gzip 1
765compression, when reading or writing archive files.
766.It Fl A
767Do not strip leading `/'s from file names.
768.It Fl B Ar bytes
769Limit the number of bytes written to a single archive volume to
770.Ar bytes .
771The
772.Ar bytes
773limit can end with
774.Li m ,
775.Li k ,
776or
777.Li b
778to specify multiplication by 1048576 (1M), 1024 (1K) or 512, respectively.
779A pair of
780.Ar bytes
781limits can be separated by
782.Li x
783to indicate a product.
784.Pp
785.Em Warning :
786Only use this option when writing an archive to a device which supports
787an end of file read condition based on last (or largest) write offset
788(such as a regular file or a tape drive).
789The use of this option with a floppy or hard disk is not recommended.
790.It Fl D
791This option is the same as the
792.Fl u
793option, except that the file inode change time is checked instead of the
794file modification time.
795The file inode change time can be used to select files whose inode information
796(e.g. uid, gid, etc.) is newer than a copy of the file in the destination
797.Ar directory .
798.It Fl E Ar limit
799Limit the number of consecutive read faults while trying to read a flawed
800archives to
801.Ar limit .
802With a positive
803.Ar limit ,
804.Nm
805will attempt to recover from an archive read error and will
806continue processing starting with the next file stored in the archive.
807A
808.Ar limit
809of 0 will cause
810.Nm
811to stop operation after the first read error is detected on an archive volume.
812A
813.Ar limit
814of
815.Li NONE
816will cause
817.Nm
818to attempt to recover from read errors forever.
819The default
820.Ar limit
821is a small positive number of retries.
822.Pp
823.Em Warning :
824Using this option with
825.Li NONE
826should be used with extreme caution as
827.Nm
828may get stuck in an infinite loop on a very badly flawed archive.
829.It Fl G Ar group
830Select a file based on its
831.Ar group
832name, or when starting with a
833.Cm # ,
834a numeric gid.
835A '\e' can be used to escape the
836.Cm # .
837Multiple
838.Fl G
839options may be supplied and checking stops with the first match.
840.It Fl H
841Follow only command line symbolic links while performing a physical file
842system traversal.
843.It Fl L
844Follow all symbolic links to perform a logical file system traversal.
845.It Fl M
846During a
847.Em write
848or
849.Em copy
850operation, treat the list of files on
851.Dv standard input
852as an
853.Xr mtree 8
854.Sq specfile
855specification, and write or copy only those items in the specfile.
856.Pp
857If the file exists in the underlying file system, its permissions and
858modification time will be used unless specifically overridden by the specfile.
859An error will be raised if the type of entry in the specfile conflicts
860with that of an existing file.
861A directory entry that is marked
862.Sq Sy optional
863will not be copied (even though its contents will be).
864.Pp
865Otherwise, the entry will be
866.Sq faked-up ,
867and it is necessary to specify at least the following parameters
868in the specfile:
869.Sy type ,
870.Sy mode ,
871.Sy gname
872or
873.Sy gid ,
874and
875.Sy uname
876or
877.Sy uid ,
878.Sy device
879(in the case of block or character devices), and
880.Sy link
881(in the case of symbolic links).
882If
883.Sy time
884isn't provided, the current time will be used.
885A
886.Sq faked-up
887entry that is marked
888.Sq Sy optional
889will not be copied.
890.It Fl N Ar dbdir
891Except for lookups for the
892.Fl G
893and
894.Fl U
895options,
896use the user database text file
897.Pa master.passwd
898and group database text file
899.Pa group
900from
901.Ar dbdir ,
902rather than using the results from the system's
903.Xr getpwnam 3
904and
905.Xr getgrnam 3
906(and related) library calls.
907.It Fl O
908Force the archive to be one volume.
909If a volume ends prematurely,
910.Nm
911will not prompt for a new volume.
912This option can be useful for
913automated tasks where error recovery cannot be performed by a human.
914.It Fl P
915Do not follow symbolic links, perform a physical file system traversal.
916This is the default mode.
917.It Fl T Ar [from_date][,to_date][/[c][m]]
918Allow files to be selected based on a file modification or inode change
919time falling within a specified time range of
920.Ar from_date
921to
922.Ar to_date
923(the dates are inclusive).
924If only a
925.Ar from_date
926is supplied, all files with a modification or inode change time
927equal to or younger are selected.
928If only a
929.Ar to_date
930is supplied, all files with a modification or inode change time
931equal to or older will be selected.
932When the
933.Ar from_date
934is equal to the
935.Ar to_date ,
936only files with a modification or inode change time of exactly that
937time will be selected.
938.Pp
939When
940.Nm
941is in the
942.Em write
943or
944.Em copy
945mode, the optional trailing field
946.Ar [c][m]
947can be used to determine which file time (inode change, file modification or
948both) are used in the comparison.
949If neither is specified, the default is to use file modification time only.
950The
951.Ar m
952specifies the comparison of file modification time (the time when
953the file was last written).
954The
955.Ar c
956specifies the comparison of inode change time (the time when the file
957inode was last changed; e.g. a change of owner, group, mode, etc).
958When
959.Ar c
960and
961.Ar m
962are both specified, then the modification and inode change times are
963both compared.
964The inode change time comparison is useful in selecting files whose
965attributes were recently changed or selecting files which were recently
966created and had their modification time reset to an older time (as what
967happens when a file is extracted from an archive and the modification time
968is preserved).
969Time comparisons using both file times is useful when
970.Nm
971is used to create a time based incremental archive (only files that were
972changed during a specified time range will be archived).
973.Pp
974A time range is made up of seven different fields and each field must contain
975two digits.
976The format is:
977.Dl [[[[[cc]yy]mm]dd]hh]mm[\&.ss]
978where
979.Cm cc
980is the first two digits of the year (the century),
981.Cm yy
982is the last two digits of the year,
983the first
984.Cm mm
985is the month (from 01 to 12),
986.Cm dd
987is the day of the month (from 01 to 31),
988.Cm hh
989is the hour of the day (from 00 to 23),
990the second
991.Cm mm
992is the minute (from 00 to 59),
993and
994.Cm ss
995is the seconds (from 00 to 61).
996Only the minute field
997.Cm mm
998is required; the others will default to the current system values.
999The
1000.Cm ss
1001field may be added independently of the other fields.
1002If the century is not specified, it defaults to 1900 for
1003years between 69 and 99, or 2000 for years between 0 and 68.
1004Time ranges are relative to the current time, so
1005.Dl Fl T Ar 1234/cm
1006would select all files with a modification or inode change time
1007of 12:34 PM today or later.
1008Multiple
1009.Fl T
1010time range can be supplied and checking stops with the first match.
1011.It Fl U Ar user
1012Select a file based on its
1013.Ar user
1014name, or when starting with a
1015.Cm # ,
1016a numeric uid.
1017A '\e' can be used to escape the
1018.Cm # .
1019Multiple
1020.Fl U
1021options may be supplied and checking stops with the first match.
1022.It Fl V
1023A final summary of archive operations is printed after they have been
1024completed.
1025Some potentially long-running tape operations are noted.
1026.It Fl X
1027When traversing the file hierarchy specified by a pathname,
1028do not descend into directories that have a different device ID.
1029See the
1030.Li st_dev
1031field as described in
1032.Xr stat 2
1033for more information about device ID's.
1034.It Fl Y
1035This option is the same as the
1036.Fl D
1037option, except that the inode change time is checked using the
1038pathname created after all the file name modifications have completed.
1039.It Fl Z
1040This option is the same as the
1041.Fl u
1042option, except that the modification time is checked using the
1043pathname created after all the file name modifications have completed.
1044.It Fl 0
1045Use the nul character instead of \en as the file separator when reading
1046files from standard input.
1047.It Fl Fl force-local
1048Do not interpret filenames that contain a `:' as remote files.
1049.It Fl Fl insecure
1050Normally
1051.Nm
1052ignores filenames that contain
1053.Dq ..
1054as a path component.
1055With this option,
1056files that contain
1057.Dq ..
1058can be processed.
1059.It Fl Fl use-compress-program
1060Use the named program as the program to decompress the input or compress
1061the output.
1062.El
1063.Pp
1064The options that operate on the names of files or archive members
1065.Fl ( c ,
1066.Fl i ,
1067.Fl n ,
1068.Fl s ,
1069.Fl u ,
1070.Fl v ,
1071.Fl D ,
1072.Fl G ,
1073.Fl T ,
1074.Fl U ,
1075.Fl Y ,
1076and
1077.Fl Z )
1078interact as follows.
1079.Pp
1080When extracting files during a
1081.Em read
1082operation, archive members are
1083.Sq selected ,
1084based only on the user specified pattern operands as modified by the
1085.Fl c ,
1086.Fl n ,
1087.Fl u ,
1088.Fl D ,
1089.Fl G ,
1090.Fl T ,
1091.Fl U
1092options.
1093Then any
1094.Fl s
1095and
1096.Fl i
1097options will modify in that order, the names of these selected files.
1098Then the
1099.Fl Y
1100and
1101.Fl Z
1102options will be applied based on the final pathname.
1103Finally the
1104.Fl v
1105option will write the names resulting from these modifications.
1106.Pp
1107When archiving files during a
1108.Em write
1109operation, or copying files during a
1110.Em copy
1111operation, archive members are
1112.Sq selected ,
1113based only on the user specified pathnames as modified by the
1114.Fl n ,
1115.Fl u ,
1116.Fl D ,
1117.Fl G ,
1118.Fl T ,
1119and
1120.Fl U
1121options (the
1122.Fl D
1123option only applies during a copy operation).
1124Then any
1125.Fl s
1126and
1127.Fl i
1128options will modify in that order, the names of these selected files.
1129Then during a
1130.Em copy
1131operation the
1132.Fl Y
1133and the
1134.Fl Z
1135options will be applied based on the final pathname.
1136Finally the
1137.Fl v
1138option will write the names resulting from these modifications.
1139.Pp
1140When one or both of the
1141.Fl u
1142or
1143.Fl D
1144options are specified along with the
1145.Fl n
1146option, a file is not considered selected unless it is newer
1147than the file to which it is compared.
1148.Sh EXIT STATUS
1149.Nm
1150will exit with one of the following values:
1151.Bl -tag -width 2n
1152.It 0
1153All files were processed successfully.
1154.It 1
1155An error occurred.
1156.El
1157.Pp
1158Whenever
1159.Nm
1160cannot create a file or a link when reading an archive or cannot
1161find a file when writing an archive, or cannot preserve the user ID,
1162group ID, or file mode when the
1163.Fl p
1164option is specified, a diagnostic message is written to
1165.Dv standard error
1166and a non-zero exit status will be returned, but processing will continue.
1167In the case where pax cannot create a link to a file,
1168.Nm
1169will not create a second copy of the file.
1170.Pp
1171If the extraction of a file from an archive is prematurely terminated by
1172a signal or error,
1173.Nm
1174may have only partially extracted a file the user wanted.
1175Additionally, the file modes of extracted files and directories
1176may have incorrect file bits, and the modification and access times may be
1177wrong.
1178.Pp
1179If the creation of an archive is prematurely terminated by a signal or error,
1180.Nm
1181may have only partially created the archive which may violate the specific
1182archive format specification.
1183.Pp
1184If while doing a
1185.Em copy ,
1186.Nm
1187detects a file is about to overwrite itself, the file is not copied,
1188a diagnostic message is written to
1189.Dv standard error
1190and when
1191.Nm
1192completes it will exit with a non-zero exit status.
1193.Sh EXAMPLES
1194The command:
1195.Dl pax -w -f /dev/rst0 \&.
1196copies the contents of the current directory to the device
1197.Pa /dev/rst0 .
1198.Pp
1199The command:
1200.Dl pax -v -f filename
1201gives the verbose table of contents for an archive stored in
1202.Pa filename .
1203.Pp
1204The following commands:
1205.Dl mkdir newdir
1206.Dl cd olddir
1207.Dl pax -rw -pp .\ ../newdir
1208will copy the entire
1209.Pa olddir
1210directory hierarchy to
1211.Pa newdir ,
1212preserving permissions and access times.
1213.Pp
1214When running as root, one may also wish to preserve file
1215ownership when copying directory trees.
1216This can be done with the following commands:
1217.Dl cd olddir
1218.Dl pax -rw -pe .\ ../newdir
1219which will copy the contents of
1220.Pa olddir
1221into
1222.Pa ../newdir ,
1223preserving ownership, permissions and access times.
1224.Pp
1225The command:
1226.Dl pax -r -s ',^//*usr//*,,' -f a.pax
1227reads the archive
1228.Pa a.pax ,
1229with all files rooted in ``/usr'' into the archive extracted relative to the
1230current directory.
1231.Pp
1232The command:
1233.Dl pax -rw -i .\ dest_dir
1234can be used to interactively select the files to copy from the current
1235directory to
1236.Pa dest_dir .
1237.Pp
1238The command:
1239.Dl pax -r -pe -U root -G bin -f a.pax
1240will extract all files from the archive
1241.Pa a.pax
1242which are owned by
1243.Em root
1244with group
1245.Em bin
1246and will preserve all file permissions.
1247.Pp
1248The command:
1249.Dl pax -r -w -v -Y -Z home /backup
1250will update (and list) only those files in the destination directory
1251.Pa /backup
1252which are older (less recent inode change or file modification times) than
1253files with the same name found in the source file tree
1254.Pa home .
1255.Sh SEE ALSO
1256.Xr cpio 1 ,
1257.Xr tar 1 ,
1258.Xr symlink 7 ,
1259.Xr mtree 8
1260.Sh STANDARDS
1261The
1262.Nm
1263utility is a superset of the
1264.St -p1003.2
1265standard.
1266The options
1267.Fl B ,
1268.Fl D ,
1269.Fl E ,
1270.Fl G ,
1271.Fl H ,
1272.Fl L ,
1273.Fl M ,
1274.Fl O ,
1275.Fl P ,
1276.Fl T ,
1277.Fl U ,
1278.Fl Y ,
1279.Fl Z ,
1280.Fl z ,
1281the archive formats
1282.Ar bcpio ,
1283.Ar sv4cpio ,
1284.Ar sv4crc ,
1285.Ar tar ,
1286and the flawed archive handling during
1287.Ar list
1288and
1289.Ar read
1290operations are extensions to the
1291.Tn POSIX
1292standard.
1293.Sh HISTORY
1294A
1295.Nm
1296utility appeared in
1297.Bx 4.4 .
1298.Sh AUTHORS
1299.An -nosplit
1300.An Keith Muller
1301at the University of California, San Diego.
1302.An Luke Mewburn
1303implemented
1304.Fl M .
1305