xref: /freebsd/bin/pax/pax.1 (revision 6ff45b4e359dda3461826bd092bd8b1be2e7d572)
1.\"-
2.\" Copyright (c) 1992 Keith Muller.
3.\" Copyright (c) 1992, 1993
4.\"	The Regents of the University of California.  All rights reserved.
5.\"
6.\" This code is derived from software contributed to Berkeley by
7.\" Keith Muller of the University of California, San Diego.
8.\"
9.\" Redistribution and use in source and binary forms, with or without
10.\" modification, are permitted provided that the following conditions
11.\" are met:
12.\" 1. Redistributions of source code must retain the above copyright
13.\"    notice, this list of conditions and the following disclaimer.
14.\" 2. Redistributions in binary form must reproduce the above copyright
15.\"    notice, this list of conditions and the following disclaimer in the
16.\"    documentation and/or other materials provided with the distribution.
17.\" 4. Neither the name of the University nor the names of its contributors
18.\"    may be used to endorse or promote products derived from this software
19.\"    without specific prior written permission.
20.\"
21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31.\" SUCH DAMAGE.
32.\"
33.\"	@(#)pax.1	8.4 (Berkeley) 4/18/94
34.\" $FreeBSD$
35.\"
36.Dd July 3, 2004
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 cdnvz
45.Bk -words
46.Op Fl f Ar archive
47.Ek
48.Bk -words
49.Op Fl s Ar replstr
50.Ar ...\&
51.Ek
52.Bk -words
53.Op Fl U Ar user
54.Ar ...\&
55.Ek
56.Bk -words
57.Op Fl G Ar group
58.Ar ...\&
59.Ek
60.Bk -words
61.Oo
62.Fl T
63.Op Ar from_date
64.Op Ar ,to_date
65.Oc
66.Ar ...\&
67.Ek
68.Op Ar pattern ...\&
69.Nm
70.Fl r
71.Op Fl cdiknuvzDYZ
72.Bk -words
73.Op Fl f Ar archive
74.Ek
75.Bk -words
76.Op Fl o Ar options
77.Ar ...\&
78.Ek
79.Bk -words
80.Op Fl p Ar string
81.Ar ...\&
82.Ek
83.Bk -words
84.Op Fl s Ar replstr
85.Ar ...\&
86.Ek
87.Op Fl E Ar limit
88.Bk -words
89.Op Fl U Ar user
90.Ar ...\&
91.Ek
92.Bk -words
93.Op Fl G Ar group
94.Ar ...\&
95.Ek
96.Bk -words
97.Oo
98.Fl T
99.Op Ar from_date
100.Op Ar ,to_date
101.Oc
102.Ar ...\&
103.Ek
104.Op Ar pattern ...\&
105.Nm
106.Fl w
107.Op Fl dituvzHLPX
108.Bk -words
109.Op Fl b Ar blocksize
110.Ek
111.Oo
112.Op Fl a
113.Op Fl f Ar archive
114.Oc
115.Bk -words
116.Op Fl x Ar format
117.Ek
118.Bk -words
119.Op Fl s Ar replstr
120.Ar ...\&
121.Ek
122.Bk -words
123.Op Fl o Ar options
124.Ar ...\&
125.Ek
126.Bk -words
127.Op Fl U Ar user
128.Ar ...\&
129.Ek
130.Bk -words
131.Op Fl G Ar group
132.Ar ...\&
133.Ek
134.Bk -words
135.Op Fl B Ar bytes
136.Ek
137.Bk -words
138.Oo
139.Fl T
140.Op Ar from_date
141.Op Ar ,to_date
142.Op Ar /[c][m]
143.Oc
144.Ar ...\&
145.Ek
146.Op Ar
147.Nm
148.Fl r
149.Fl w
150.Op Fl diklntuvDHLPXYZ
151.Bk -words
152.Op Fl p Ar string
153.Ar ...\&
154.Ek
155.Bk -words
156.Op Fl s Ar replstr
157.Ar ...\&
158.Ek
159.Bk -words
160.Op Fl U Ar user
161.Ar ...\&
162.Ek
163.Bk -words
164.Op Fl G Ar group
165.Ar ...\&
166.Ek
167.Bk -words
168.Oo
169.Fl T
170.Op Ar from_date
171.Op Ar ,to_date
172.Op Ar /[c][m]
173.Oc
174.Ar ...\&
175.Ek
176.Op Ar
177.Ar directory
178.Sh DESCRIPTION
179The
180.Nm
181utility will read, write, and list the members of an archive file,
182and will copy directory hierarchies.
183These operations are independent of the specific archive format,
184and support a wide variety of different archive formats.
185A list of supported archive formats can be found under the description of the
186.Fl x
187option.
188.Pp
189The presence of the
190.Fl r
191and the
192.Fl w
193options specifies which of the following functional modes
194.Nm
195will operate under:
196.Em list , read , write ,
197and
198.Em copy .
199.Bl -tag -width 6n
200.It <none>
201.Em List .
202Write to
203.Dv standard output
204a table of contents of the members of the archive file read from
205.Dv standard input ,
206whose pathnames match the specified
207.Ar patterns .
208The table of contents contains one filename per line
209and is written using single line buffering.
210.It Fl r
211.Em Read .
212Extract the members of the archive file read from the
213.Dv standard input ,
214with pathnames matching the specified
215.Ar patterns .
216The archive format and blocking is automatically determined on input.
217When an extracted file is a directory, the entire file hierarchy
218rooted at that directory is extracted.
219All extracted files are created relative to the current file hierarchy.
220The setting of ownership, access and modification times, and file mode of
221the extracted files are discussed in more detail under the
222.Fl p
223option.
224.It Fl w
225.Em Write .
226Write an archive containing the
227.Ar file
228operands to
229.Dv standard output
230using the specified archive format.
231When no
232.Ar file
233operands are specified, a list of files to copy with one per line is read from
234.Dv standard input .
235When a
236.Ar file
237operand is also a directory, the entire file hierarchy rooted
238at that directory will be included.
239.It Fl r Fl w
240.Em Copy .
241Copy the
242.Ar file
243operands to the destination
244.Ar directory .
245When no
246.Ar file
247operands are specified, a list of files to copy with one per line is read from
248the
249.Dv standard input .
250When a
251.Ar file
252operand is also a directory the entire file
253hierarchy rooted at that directory will be included.
254The effect of the
255.Em copy
256is as if the copied files were written to an archive file and then
257subsequently extracted, except that there may be hard links between
258the original and the copied files (see the
259.Fl l
260option below).
261.Pp
262.Em Warning :
263The destination
264.Ar directory
265must not be one of the
266.Ar file
267operands or a member of a file hierarchy rooted at one of the
268.Ar file
269operands.
270The result of a
271.Em copy
272under these conditions is unpredictable.
273.El
274.Pp
275While processing a damaged archive during a
276.Em read
277or
278.Em list
279operation,
280.Nm
281will attempt to recover from media defects and will search through the archive
282to locate and process the largest number of archive members possible (see the
283.Fl E
284option for more details on error handling).
285.Sh OPERANDS
286The
287.Ar directory
288operand specifies a destination directory pathname.
289If the
290.Ar directory
291operand does not exist, or it is not writable by the user,
292or it is not of type directory,
293.Nm
294will exit with a non-zero exit status.
295.Pp
296The
297.Ar pattern
298operand is used to select one or more pathnames of archive members.
299Archive members are selected using the pattern matching notation described
300by
301.Xr fnmatch 3 .
302When the
303.Ar pattern
304operand is not supplied, all members of the archive will be selected.
305When a
306.Ar pattern
307matches a directory, the entire file hierarchy rooted at that directory will
308be selected.
309When a
310.Ar pattern
311operand does not select at least one archive member,
312.Nm
313will write these
314.Ar pattern
315operands in a diagnostic message to
316.Dv standard error
317and then exit with a non-zero exit status.
318.Pp
319The
320.Ar file
321operand specifies the pathname of a file to be copied or archived.
322When a
323.Ar file
324operand does not select at least one archive member,
325.Nm
326will write these
327.Ar file
328operand pathnames in a diagnostic message to
329.Dv standard error
330and then exit with a non-zero exit status.
331.Sh OPTIONS
332The following options are supported:
333.Bl -tag -width 4n
334.It Fl r
335Read an archive file from
336.Dv standard input
337and extract the specified
338.Ar files .
339If any intermediate directories are needed in order to extract an archive
340member, these directories will be created as if
341.Xr mkdir 2
342was called with the bitwise inclusive
343.Dv OR
344of
345.Dv S_IRWXU , S_IRWXG ,
346and
347.Dv S_IRWXO
348as the mode argument.
349When the selected archive format supports the specification of linked
350files and these files cannot be linked while the archive is being extracted,
351.Nm
352will write a diagnostic message to
353.Dv standard error
354and exit with a non-zero exit status at the completion of operation.
355.It Fl w
356Write files to the
357.Dv standard output
358in the specified archive format.
359When no
360.Ar file
361operands are specified,
362.Dv standard input
363is read for a list of pathnames with one per line without any leading or
364trailing
365.Aq blanks .
366.It Fl a
367Append
368.Ar files
369to the end of an archive that was previously written.
370If an archive format is not specified with a
371.Fl x
372option, the format currently being used in the archive will be selected.
373Any attempt to append to an archive in a format different from the
374format already used in the archive will cause
375.Nm
376to exit immediately
377with a non-zero exit status.
378The blocking size used in the archive volume where writing starts
379will continue to be used for the remainder of that archive volume.
380.Pp
381.Em Warning :
382Many storage devices are not able to support the operations necessary
383to perform an append operation.
384Any attempt to append to an archive stored on such a device may damage the
385archive or have other unpredictable results.
386Tape drives in particular are more likely to not support an append operation.
387An archive stored in a regular file system file or on a disk device will
388usually support an append operation.
389.It Fl b Ar blocksize
390When
391.Em writing
392an archive,
393block the output at a positive decimal integer number of
394bytes per write to the archive file.
395The
396.Ar blocksize
397must be a multiple of 512 bytes with a maximum of 64512 bytes. A
398.Ar blocksize
399larger than 32256 bytes violates the
400.Tn POSIX
401standard and will not be portable to all systems.
402A
403.Ar blocksize
404can end with
405.Li k
406or
407.Li b
408to specify multiplication by 1024 (1K) or 512, respectively.
409A pair of
410.Ar blocksizes
411can be separated by
412.Li x
413to indicate a product.
414A specific archive device may impose additional restrictions on the size
415of blocking it will support.
416When blocking is not specified, the default
417.Ar blocksize
418is dependent on the specific archive format being used (see the
419.Fl x
420option).
421.It Fl c
422Match all file or archive members
423.Em except
424those specified by the
425.Ar pattern
426and
427.Ar file
428operands.
429.It Fl d
430Cause files of type directory being copied or archived, or archive members of
431type directory being extracted, to match only the directory file or archive
432member and not the file hierarchy rooted at the directory.
433.It Fl f Ar archive
434Specify
435.Ar archive
436as the pathname of the input or output archive, overriding the default
437.Dv standard input
438(for
439.Em list
440and
441.Em read )
442or
443.Dv standard output
444(for
445.Em write ) .
446A single archive may span multiple files and different archive devices.
447When required,
448.Nm
449will prompt for the pathname of the file or device of the next volume in the
450archive.
451.It Fl i
452Interactively rename files or archive members.
453For each archive member matching a
454.Ar pattern
455operand or each file matching a
456.Ar file
457operand,
458.Nm
459will prompt to
460.Pa /dev/tty
461giving the name of the file, its file mode and its modification time.
462The
463.Nm
464utility will then read a line from
465.Pa /dev/tty .
466If this line is blank, the file or archive member is skipped.
467If this line consists of a single period, the
468file or archive member is processed with no modification to its name.
469Otherwise, its name is replaced with the contents of the line.
470The
471.Nm
472utility will immediately exit with a non-zero exit status if
473.Dv <EOF>
474is encountered when reading a response or if
475.Pa /dev/tty
476cannot be opened for reading and writing.
477.It Fl k
478Do not overwrite existing files.
479.It Fl l
480Link files.
481(The letter ell).
482In the
483.Em copy
484mode
485.Pq Fl r w ,
486hard links are made between the source and destination file hierarchies
487whenever possible.
488.It Fl n
489Select the first archive member that matches each
490.Ar pattern
491operand.
492No more than one archive member is matched for each
493.Ar pattern .
494When members of type directory are matched, the file hierarchy rooted at that
495directory is also matched (unless
496.Fl d
497is also specified).
498.It Fl o Ar options
499Information to modify the algorithm for extracting or writing archive files
500which is specific to the archive format specified by
501.Fl x .
502In general,
503.Ar options
504take the form:
505.Cm name=value
506.It Fl p Ar string
507Specify one or more file characteristic options (privileges).
508The
509.Ar string
510option-argument is a string specifying file characteristics to be retained or
511discarded on extraction.
512The string consists of the specification characters
513.Cm a , e , m , o ,
514and
515.Cm p .
516Multiple characteristics can be concatenated within the same string
517and multiple
518.Fl p
519options can be specified.
520The meaning of the specification characters are as follows:
521.Bl -tag -width 2n
522.It Cm a
523Do not preserve file access times.
524By default, file access times are preserved whenever possible.
525.It Cm e
526.Sq Preserve everything ,
527the user ID, group ID, file mode bits,
528file access time, and file modification time.
529This is intended to be used by
530.Em root ,
531someone with all the appropriate privileges, in order to preserve all
532aspects of the files as they are recorded in the archive.
533The
534.Cm e
535flag is the sum of the
536.Cm o
537and
538.Cm p
539flags.
540.It Cm m
541Do not preserve file modification times.
542By default, file modification times are preserved whenever possible.
543.It Cm o
544Preserve the user ID and group ID.
545.It Cm p
546.Sq Preserve
547the file mode bits.
548This intended to be used by a
549.Em user
550with regular privileges who wants to preserve all aspects of the file other
551than the ownership.
552The file times are preserved by default, but two other flags are offered to
553disable this and use the time of extraction instead.
554.El
555.Pp
556In the preceding list,
557.Sq preserve
558indicates that an attribute stored in the archive is given to the
559extracted file, subject to the permissions of the invoking
560process.
561Otherwise the attribute of the extracted file is determined as
562part of the normal file creation action.
563If neither the
564.Cm e
565nor the
566.Cm o
567specification character is specified, or the user ID and group ID are not
568preserved for any reason,
569.Nm
570will not set the
571.Dv S_ISUID
572.Em ( setuid )
573and
574.Dv S_ISGID
575.Em ( setgid )
576bits of the file mode.
577If the preservation of any of these items fails for any reason,
578.Nm
579will write a diagnostic message to
580.Dv standard error .
581Failure to preserve these items will affect the final exit status,
582but will not cause the extracted file to be deleted.
583If the file characteristic letters in any of the string option-arguments are
584duplicated or conflict with each other, the one(s) given last will take
585precedence.
586For example, if
587.Dl Fl p Ar eme
588is specified, file modification times are still preserved.
589.It Fl s Ar replstr
590Modify the file or archive member names specified by the
591.Ar pattern
592or
593.Ar file
594operands according to the substitution expression
595.Ar replstr ,
596using the syntax of the
597.Xr ed 1
598utility regular expressions.
599The format of these regular expressions are:
600.Dl /old/new/[gp]
601As in
602.Xr ed 1 ,
603.Cm old
604is a basic regular expression and
605.Cm new
606can contain an ampersand (&), \\n (where n is a digit) back-references,
607or subexpression matching.
608The
609.Cm old
610string may also contain
611.Dv <newline>
612characters.
613Any non-null character can be used as a delimiter (/ is shown here).
614Multiple
615.Fl s
616expressions can be specified.
617The expressions are applied in the order they are specified on the
618command line, terminating with the first successful substitution.
619The optional trailing
620.Cm g
621continues to apply the substitution expression to the pathname substring
622which starts with the first character following the end of the last successful
623substitution.
624The first unsuccessful substitution stops the operation of the
625.Cm g
626option.
627The optional trailing
628.Cm p
629will cause the final result of a successful substitution to be written to
630.Dv standard error
631in the following format:
632.Dl <original pathname> >> <new pathname>
633File or archive member names that substitute to the empty string
634are not selected and will be skipped.
635.It Fl t
636Reset the access times of any file or directory read or accessed by
637.Nm
638to be the same as they were before being read or accessed by
639.Nm .
640.It Fl u
641Ignore files that are older (having a less recent file modification time)
642than a pre-existing file or archive member with the same name.
643During
644.Em read ,
645an archive member with the same name as a file in the file system will be
646extracted if the archive member is newer than the file.
647During
648.Em write ,
649a file system member with the same name as an archive member will be
650written to the archive if it is newer than the archive member.
651During
652.Em copy ,
653the file in the destination hierarchy is replaced by the file in the source
654hierarchy or by a link to the file in the source hierarchy if the file in
655the source hierarchy is newer.
656.It Fl v
657During a
658.Em list
659operation, produce a verbose table of contents using the format of the
660.Xr ls 1
661utility with the
662.Fl l
663option.
664For pathnames representing a hard link to a previous member of the archive,
665the output has the format:
666.Dl <ls -l listing> == <link name>
667For pathnames representing a symbolic link, the output has the format:
668.Dl <ls -l listing> => <link name>
669Where <ls -l listing> is the output format specified by the
670.Xr ls 1
671utility when used with the
672.Fl l
673option.
674Otherwise for all the other operational modes
675.Em ( read , write ,
676and
677.Em copy ) ,
678pathnames are written and flushed to
679.Dv standard error
680without a trailing
681.Dv <newline>
682as soon as processing begins on that file or
683archive member.
684The trailing
685.Dv <newline> ,
686is not buffered, and is written only after the file has been read or written.
687.It Fl x Ar format
688Specify the output archive format, with the default format being
689.Ar ustar .
690The
691.Nm
692utility currently supports the following formats:
693.Bl -tag -width "sv4cpio"
694.It Ar cpio
695The extended cpio interchange format specified in the
696.St -p1003.2
697standard.
698The default blocksize for this format is 5120 bytes.
699Inode and device information about a file (used for detecting file hard links
700by this format) which may be truncated by this format is detected by
701.Nm
702and is repaired.
703.It Ar bcpio
704The old binary cpio format.
705The default blocksize for this format is 5120 bytes.
706This format is not very portable and should not be used when other formats
707are available.
708Inode and device information about a file (used for detecting file hard links
709by this format) which may be truncated by this format is detected by
710.Nm
711and is repaired.
712.It Ar sv4cpio
713The System V release 4 cpio.
714The default blocksize for this format is 5120 bytes.
715Inode and device information about a file (used for detecting file hard links
716by this format) which may be truncated by this format is detected by
717.Nm
718and is repaired.
719.It Ar sv4crc
720The System V release 4 cpio with file crc checksums.
721The default blocksize for this format is 5120 bytes.
722Inode and device information about a file (used for detecting file hard links
723by this format) which may be truncated by this format is detected by
724.Nm
725and is repaired.
726.It Ar tar
727The old
728.Bx
729tar format as found in
730.Bx 4.3 .
731The default blocksize for this format is 10240 bytes.
732Pathnames stored by this format must be 100 characters or less in length.
733Only
734.Em regular
735files,
736.Em hard links , soft links ,
737and
738.Em directories
739will be archived (other file system types are not supported).
740For backwards compatibility with even older tar formats, a
741.Fl o
742option can be used when writing an archive to omit the storage of directories.
743This option takes the form:
744.Dl Fl o Cm write_opt=nodir
745.It Ar ustar
746The extended tar interchange format specified in the
747.St -p1003.2
748standard.
749The default blocksize for this format is 10240 bytes.
750Pathnames stored by this format must be 250 characters or less in length.
751.El
752.Pp
753The
754.Nm
755utility will detect and report any file that it is unable to store or extract
756as the result of any specific archive format restrictions.
757The individual archive formats may impose additional restrictions on use.
758Typical archive format restrictions include (but are not limited to):
759file pathname length, file size, link pathname length and the type of the file.
760.It Fl z
761Use
762.Xr gzip 1
763to compress (decompress) the archive while writing (reading).
764Incompatible with
765.Fl a .
766.It Fl B Ar bytes
767Limit the number of bytes written to a single archive volume to
768.Ar bytes .
769The
770.Ar bytes
771limit can end with
772.Li m ,
773.Li k ,
774or
775.Li b
776to specify multiplication by 1048576 (1M), 1024 (1K) or 512, respectively.
777A pair of
778.Ar bytes
779limits can be separated by
780.Li x
781to indicate a product.
782.Pp
783.Em Warning :
784Only use this option when writing an archive to a device which supports
785an end of file read condition based on last (or largest) write offset
786(such as a regular file or a tape drive).
787The use of this option with a floppy or hard disk is not recommended.
788.It Fl D
789This option is the same as the
790.Fl u
791option, except that the file inode change time is checked instead of the
792file modification time.
793The file inode change time can be used to select files whose inode information
794(e.g.\& uid, gid, etc.) is newer than a copy of the file in the destination
795.Ar directory .
796.It Fl E Ar limit
797Limit the number of consecutive read faults while trying to read a flawed
798archives to
799.Ar limit .
800With a positive
801.Ar limit ,
802.Nm
803will attempt to recover from an archive read error and will
804continue processing starting with the next file stored in the archive.
805A
806.Ar limit
807of 0 will cause
808.Nm
809to stop operation after the first read error is detected on an archive volume.
810A
811.Ar limit
812of
813.Li NONE
814will cause
815.Nm
816to attempt to recover from read errors forever.
817The default
818.Ar limit
819is a small positive number of retries.
820.Pp
821.Em Warning :
822Using this option with
823.Li NONE
824should be used with extreme caution as
825.Nm
826may get stuck in an infinite loop on a very badly flawed archive.
827.It Fl G Ar group
828Select a file based on its
829.Ar group
830name, or when starting with a
831.Cm # ,
832a numeric gid.
833A '\\' can be used to escape the
834.Cm # .
835Multiple
836.Fl G
837options may be supplied and checking stops with the first match.
838.It Fl H
839Follow only command line symbolic links while performing a physical file
840system traversal.
841.It Fl L
842Follow all symbolic links to perform a logical file system traversal.
843.It Fl P
844Do not follow symbolic links, perform a physical file system traversal.
845This is the default mode.
846.It Fl T Ar [from_date][,to_date][/[c][m]]
847Allow files to be selected based on a file modification or inode change
848time falling within a specified time range of
849.Ar from_date
850to
851.Ar to_date
852(the dates are inclusive).
853If only a
854.Ar from_date
855is supplied, all files with a modification or inode change time
856equal to or younger are selected.
857If only a
858.Ar to_date
859is supplied, all files with a modification or inode change time
860equal to or older will be selected.
861When the
862.Ar from_date
863is equal to the
864.Ar to_date ,
865only files with a modification or inode change time of exactly that
866time will be selected.
867.Pp
868When
869.Nm
870is in the
871.Em write
872or
873.Em copy
874mode, the optional trailing field
875.Ar [c][m]
876can be used to determine which file time (inode change, file modification or
877both) are used in the comparison.
878If neither is specified, the default is to use file modification time only.
879The
880.Ar m
881specifies the comparison of file modification time (the time when
882the file was last written).
883The
884.Ar c
885specifies the comparison of inode change time (the time when the file
886inode was last changed; e.g.\& a change of owner, group, mode, etc).
887When
888.Ar c
889and
890.Ar m
891are both specified, then the modification and inode change times are
892both compared.
893The inode change time comparison is useful in selecting files whose
894attributes were recently changed or selecting files which were recently
895created and had their modification time reset to an older time (as what
896happens when a file is extracted from an archive and the modification time
897is preserved).
898Time comparisons using both file times is useful when
899.Nm
900is used to create a time based incremental archive (only files that were
901changed during a specified time range will be archived).
902.Pp
903A time range is made up of six different fields and each field must contain two
904digits.
905The format is:
906.Dl [yy[mm[dd[hh]]]]mm[.ss]
907Where
908.Cm yy
909is the last two digits of the year,
910the first
911.Cm mm
912is the month (from 01 to 12),
913.Cm dd
914is the day of the month (from 01 to 31),
915.Cm hh
916is the hour of the day (from 00 to 23),
917the second
918.Cm mm
919is the minute (from 00 to 59),
920and
921.Cm ss
922is the seconds (from 00 to 59).
923The minute field
924.Cm mm
925is required, while the other fields are optional and must be added in the
926following order:
927.Dl Cm hh , dd , mm , yy .
928The
929.Cm ss
930field may be added independently of the other fields.
931Time ranges are relative to the current time, so
932.Dl Fl T Ar 1234/cm
933would select all files with a modification or inode change time
934of 12:34 PM today or later.
935Multiple
936.Fl T
937time range can be supplied and checking stops with the first match.
938.It Fl U Ar user
939Select a file based on its
940.Ar user
941name, or when starting with a
942.Cm # ,
943a numeric uid.
944A '\\' can be used to escape the
945.Cm # .
946Multiple
947.Fl U
948options may be supplied and checking stops with the first match.
949.It Fl X
950When traversing the file hierarchy specified by a pathname,
951do not descend into directories that have a different device ID.
952See the
953.Li st_dev
954field as described in
955.Xr stat 2
956for more information about device ID's.
957.It Fl Y
958This option is the same as the
959.Fl D
960option, except that the inode change time is checked using the
961pathname created after all the file name modifications have completed.
962.It Fl Z
963This option is the same as the
964.Fl u
965option, except that the modification time is checked using the
966pathname created after all the file name modifications have completed.
967.El
968.Pp
969The options that operate on the names of files or archive members
970.Fl ( c ,
971.Fl i ,
972.Fl n ,
973.Fl s ,
974.Fl u ,
975.Fl v ,
976.Fl D ,
977.Fl G ,
978.Fl T ,
979.Fl U ,
980.Fl Y ,
981and
982.Fl Z )
983interact as follows.
984.Pp
985When extracting files during a
986.Em read
987operation, archive members are
988.Sq selected ,
989based only on the user specified pattern operands as modified by the
990.Fl c ,
991.Fl n ,
992.Fl u ,
993.Fl D ,
994.Fl G ,
995.Fl T ,
996.Fl U
997options.
998Then any
999.Fl s
1000and
1001.Fl i
1002options will modify in that order, the names of these selected files.
1003Then the
1004.Fl Y
1005and
1006.Fl Z
1007options will be applied based on the final pathname.
1008Finally the
1009.Fl v
1010option will write the names resulting from these modifications.
1011.Pp
1012When archiving files during a
1013.Em write
1014operation, or copying files during a
1015.Em copy
1016operation, archive members are
1017.Sq selected ,
1018based only on the user specified pathnames as modified by the
1019.Fl n ,
1020.Fl u ,
1021.Fl D ,
1022.Fl G ,
1023.Fl T ,
1024and
1025.Fl U
1026options (the
1027.Fl D
1028option only applies during a copy operation).
1029Then any
1030.Fl s
1031and
1032.Fl i
1033options will modify in that order, the names of these selected files.
1034Then during a
1035.Em copy
1036operation the
1037.Fl Y
1038and the
1039.Fl Z
1040options will be applied based on the final pathname.
1041Finally the
1042.Fl v
1043option will write the names resulting from these modifications.
1044.Pp
1045When one or both of the
1046.Fl u
1047or
1048.Fl D
1049options are specified along with the
1050.Fl n
1051option, a file is not considered selected unless it is newer
1052than the file to which it is compared.
1053.Sh EXIT STATUS
1054The
1055.Nm
1056utility will exit with one of the following values:
1057.Bl -tag -width 2n
1058.It 0
1059All files were processed successfully.
1060.It 1
1061An error occurred.
1062.El
1063.Sh EXAMPLES
1064The command:
1065.Dl "pax -w -f /dev/sa0 ."
1066copies the contents of the current directory to the device
1067.Pa /dev/sa0 .
1068.Pp
1069The command:
1070.Dl pax -v -f filename
1071gives the verbose table of contents for an archive stored in
1072.Pa filename .
1073.Pp
1074The following commands:
1075.Dl mkdir /tmp/to
1076.Dl cd /tmp/from
1077.Dl pax -rw .\ /tmp/to
1078will copy the entire
1079.Pa /tmp/from
1080directory hierarchy to
1081.Pa /tmp/to .
1082.Pp
1083The command:
1084.Dl pax -r -s ',^//*usr//*,,' -f a.pax
1085reads the archive
1086.Pa a.pax ,
1087with all files rooted in ``/usr'' into the archive extracted relative to the
1088current directory.
1089.Pp
1090The command:
1091.Dl pax -rw -i .\ dest_dir
1092can be used to interactively select the files to copy from the current
1093directory to
1094.Pa dest_dir .
1095.Pp
1096The command:
1097.Dl pax -r -pe -U root -G bin -f a.pax
1098will extract all files from the archive
1099.Pa a.pax
1100which are owned by
1101.Em root
1102with group
1103.Em bin
1104and will preserve all file permissions.
1105.Pp
1106The command:
1107.Dl pax -r -w -v -Y -Z home /backup
1108will update (and list) only those files in the destination directory
1109.Pa /backup
1110which are older (less recent inode change or file modification times) than
1111files with the same name found in the source file tree
1112.Pa home .
1113.Sh DIAGNOSTICS
1114Whenever
1115.Nm
1116cannot create a file or a link when reading an archive or cannot
1117find a file when writing an archive, or cannot preserve the user ID,
1118group ID, or file mode when the
1119.Fl p
1120option is specified, a diagnostic message is written to
1121.Dv standard error
1122and a non-zero exit status will be returned, but processing will continue.
1123In the case where pax cannot create a link to a file,
1124.Nm
1125will not create a second copy of the file.
1126.Pp
1127If the extraction of a file from an archive is prematurely terminated by
1128a signal or error,
1129.Nm
1130may have only partially extracted a file the user wanted.
1131Additionally, the file modes of extracted files and directories
1132may have incorrect file bits, and the modification and access times may be
1133wrong.
1134.Pp
1135If the creation of an archive is prematurely terminated by a signal or error,
1136.Nm
1137may have only partially created the archive which may violate the specific
1138archive format specification.
1139.Pp
1140If while doing a
1141.Em copy ,
1142.Nm
1143detects a file is about to overwrite itself, the file is not copied,
1144a diagnostic message is written to
1145.Dv standard error
1146and when
1147.Nm
1148completes it will exit with a non-zero exit status.
1149.Sh SEE ALSO
1150.Xr cpio 1 ,
1151.Xr tar 1
1152.Sh STANDARDS
1153The
1154.Nm
1155utility is a superset of the
1156.St -p1003.2
1157standard.
1158The options
1159.Fl z ,
1160.Fl B ,
1161.Fl D ,
1162.Fl E ,
1163.Fl G ,
1164.Fl H ,
1165.Fl L ,
1166.Fl P ,
1167.Fl T ,
1168.Fl U ,
1169.Fl Y ,
1170.Fl Z ,
1171the archive formats
1172.Ar bcpio ,
1173.Ar sv4cpio ,
1174.Ar sv4crc ,
1175.Ar tar ,
1176and the flawed archive handling during
1177.Ar list
1178and
1179.Ar read
1180operations are extensions to the
1181.Tn POSIX
1182standard.
1183.Sh HISTORY
1184The
1185.Nm
1186utility appeared in
1187.Bx 4.4 .
1188.Sh AUTHORS
1189.An Keith Muller
1190at the University of California, San Diego
1191.Sh BUGS
1192The
1193.Nm
1194utility does not recognize multibyte characters.
1195