xref: /freebsd/bin/pax/pax.1 (revision 6990ffd8a95caaba6858ad44ff1b3157d1efba8f)
1.\" Copyright (c) 1992 Keith Muller.
2.\" Copyright (c) 1992, 1993
3.\"	The Regents of the University of California.  All rights reserved.
4.\"
5.\" This code is derived from software contributed to Berkeley by
6.\" Keith Muller of the University of California, San Diego.
7.\"
8.\" Redistribution and use in source and binary forms, with or without
9.\" modification, are permitted provided that the following conditions
10.\" are met:
11.\" 1. Redistributions of source code must retain the above copyright
12.\"    notice, this list of conditions and the following disclaimer.
13.\" 2. Redistributions in binary form must reproduce the above copyright
14.\"    notice, this list of conditions and the following disclaimer in the
15.\"    documentation and/or other materials provided with the distribution.
16.\" 3. All advertising materials mentioning features or use of this software
17.\"    must display the following acknowledgement:
18.\"	This product includes software developed by the University of
19.\"	California, Berkeley and its contributors.
20.\" 4. Neither the name of the University nor the names of its contributors
21.\"    may be used to endorse or promote products derived from this software
22.\"    without specific prior written permission.
23.\"
24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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34.\" SUCH DAMAGE.
35.\"
36.\"	@(#)pax.1	8.4 (Berkeley) 4/18/94
37.\" $FreeBSD$
38.\"
39.Dd April 18, 1994
40.Dt PAX 1
41.Os
42.Sh NAME
43.Nm pax
44.Nd read and write file archives and copy directory hierarchies
45.Sh SYNOPSIS
46.Nm
47.Op Fl cdnvz
48.Bk -words
49.Op Fl f Ar archive
50.Ek
51.Bk -words
52.Op Fl s Ar replstr
53.Ar ...\&
54.Ek
55.Bk -words
56.Op Fl U Ar user
57.Ar ...\&
58.Ek
59.Bk -words
60.Op Fl G Ar group
61.Ar ...\&
62.Ek
63.Bk -words
64.Oo
65.Fl T
66.Op Ar from_date
67.Op Ar ,to_date
68.Oc
69.Ar ...\&
70.Ek
71.Op Ar pattern ...\&
72.Nm
73.Fl r
74.Op Fl cdiknuvzDYZ
75.Bk -words
76.Op Fl f Ar archive
77.Ek
78.Bk -words
79.Op Fl o Ar options
80.Ar ...\&
81.Ek
82.Bk -words
83.Op Fl p Ar string
84.Ar ...\&
85.Ek
86.Bk -words
87.Op Fl s Ar replstr
88.Ar ...\&
89.Ek
90.Op Fl E Ar limit
91.Bk -words
92.Op Fl U Ar user
93.Ar ...\&
94.Ek
95.Bk -words
96.Op Fl G Ar group
97.Ar ...\&
98.Ek
99.Bk -words
100.Oo
101.Fl T
102.Op Ar from_date
103.Op Ar ,to_date
104.Oc
105.Ar ...\&
106.Ek
107.Op Ar pattern ...\&
108.Nm
109.Fl w
110.Op Fl dituvzHLPX
111.Bk -words
112.Op Fl b Ar blocksize
113.Ek
114.Oo
115.Op Fl a
116.Op Fl f Ar archive
117.Oc
118.Bk -words
119.Op Fl x Ar format
120.Ek
121.Bk -words
122.Op Fl s Ar replstr
123.Ar ...\&
124.Ek
125.Bk -words
126.Op Fl o Ar options
127.Ar ...\&
128.Ek
129.Bk -words
130.Op Fl U Ar user
131.Ar ...\&
132.Ek
133.Bk -words
134.Op Fl G Ar group
135.Ar ...\&
136.Ek
137.Bk -words
138.Op Fl B Ar bytes
139.Ek
140.Bk -words
141.Oo
142.Fl T
143.Op Ar from_date
144.Op Ar ,to_date
145.Op Ar /[c][m]
146.Oc
147.Ar ...\&
148.Ek
149.Op Ar
150.Nm
151.Fl r
152.Fl w
153.Op Fl diklntuvDHLPXYZ
154.Bk -words
155.Op Fl p Ar string
156.Ar ...\&
157.Ek
158.Bk -words
159.Op Fl s Ar replstr
160.Ar ...\&
161.Ek
162.Bk -words
163.Op Fl U Ar user
164.Ar ...\&
165.Ek
166.Bk -words
167.Op Fl G Ar group
168.Ar ...\&
169.Ek
170.Bk -words
171.Oo
172.Fl T
173.Op Ar from_date
174.Op Ar ,to_date
175.Op Ar /[c][m]
176.Oc
177.Ar ...\&
178.Ek
179.Op Ar
180.Ar directory
181.Sh DESCRIPTION
182.Nm Pax
183will read, write, and list the members of an archive file,
184and will copy directory hierarchies.
185.Nm Pax
186operation is independent of the specific archive format,
187and supports a wide variety of different archive formats.
188A list of supported archive formats can be found under the description of the
189.Fl x
190option.
191.Pp
192The presence of the
193.Fl r
194and the
195.Fl w
196options specifies which of the following functional modes
197.Nm
198will operate under:
199.Em list , read , write ,
200and
201.Em copy .
202.Bl -tag -width 6n
203.It <none>
204.Em List .
205.Nm Pax
206will write to
207.Dv standard output
208a table of contents of the members of the archive file read from
209.Dv standard input ,
210whose pathnames match the specified
211.Ar patterns .
212The table of contents contains one filename per line
213and is written using single line buffering.
214.It Fl r
215.Em Read .
216.Nm Pax
217extracts the members of the archive file read from the
218.Dv standard input ,
219with pathnames matching the specified
220.Ar patterns .
221The archive format and blocking is automatically determined on input.
222When an extracted file is a directory, the entire file hierarchy
223rooted at that directory is extracted.
224All extracted files are created relative to the current file hierarchy.
225The setting of ownership, access and modification times, and file mode of
226the extracted files are discussed in more detail under the
227.Fl p
228option.
229.It Fl w
230.Em Write .
231.Nm Pax
232writes an archive containing the
233.Ar file
234operands to
235.Dv standard output
236using the specified archive format.
237When no
238.Ar file
239operands are specified, a list of files to copy with one per line is read from
240.Dv standard input .
241When a
242.Ar file
243operand is also a directory, the entire file hierarchy rooted
244at that directory will be included.
245.It Fl r Fl w
246.Em Copy .
247.Nm Pax
248copies the
249.Ar file
250operands to the destination
251.Ar directory .
252When no
253.Ar file
254operands are specified, a list of files to copy with one per line is read from
255the
256.Dv standard input .
257When a
258.Ar file
259operand is also a directory the entire file
260hierarchy rooted at that directory will be included.
261The effect of the
262.Em copy
263is as if the copied files were written to an archive file and then
264subsequently extracted, except that there may be hard links between
265the original and the copied files (see the
266.Fl l
267option below).
268.Pp
269.Em Warning :
270The destination
271.Ar directory
272must not be one of the
273.Ar file
274operands or a member of a file hierarchy rooted at one of the
275.Ar file
276operands.
277The result of a
278.Em copy
279under these conditions is unpredictable.
280.El
281.Pp
282While processing a damaged archive during a
283.Em read
284or
285.Em list
286operation,
287.Nm
288will attempt to recover from media defects and will search through the archive
289to locate and process the largest number of archive members possible (see the
290.Fl E
291option for more details on error handling).
292.Sh OPERANDS
293The
294.Ar directory
295operand specifies a destination directory pathname.
296If the
297.Ar directory
298operand does not exist, or it is not writable by the user,
299or it is not of type directory,
300.Nm
301will exit with a non-zero exit status.
302.Pp
303The
304.Ar pattern
305operand is used to select one or more pathnames of archive members.
306Archive members are selected using the pattern matching notation described
307by
308.Xr fnmatch 3 .
309When the
310.Ar pattern
311operand is not supplied, all members of the archive will be selected.
312When a
313.Ar pattern
314matches a directory, the entire file hierarchy rooted at that directory will
315be selected.
316When a
317.Ar pattern
318operand does not select at least one archive member,
319.Nm
320will write these
321.Ar pattern
322operands in a diagnostic message to
323.Dv standard error
324and then exit with a non-zero exit status.
325.Pp
326The
327.Ar file
328operand specifies the pathname of a file to be copied or archived.
329When a
330.Ar file
331operand does not select at least one archive member,
332.Nm
333will write these
334.Ar file
335operand pathnames in a diagnostic message to
336.Dv standard error
337and then exit with a non-zero exit status.
338.Sh OPTIONS
339The following options are supported:
340.Bl -tag -width 4n
341.It Fl r
342Read an archive file from
343.Dv standard input
344and extract the specified
345.Ar files .
346If any intermediate directories are needed in order to extract an archive
347member, these directories will be created as if
348.Xr mkdir 2
349was called with the bitwise inclusive
350.Dv OR
351of
352.Dv S_IRWXU , S_IRWXG ,
353and
354.Dv S_IRWXO
355as the mode argument.
356When the selected archive format supports the specification of linked
357files and these files cannot be linked while the archive is being extracted,
358.Nm
359will write a diagnostic message to
360.Dv standard error
361and exit with a non-zero exit status at the completion of operation.
362.It Fl w
363Write files to the
364.Dv standard output
365in the specified archive format.
366When no
367.Ar file
368operands are specified,
369.Dv standard input
370is read for a list of pathnames with one per line without any leading or
371trailing
372.Aq blanks .
373.It Fl a
374Append
375.Ar files
376to the end of an archive that was previously written.
377If an archive format is not specified with a
378.Fl x
379option, the format currently being used in the archive will be selected.
380Any attempt to append to an archive in a format different from the
381format already used in the archive will cause
382.Nm
383to exit immediately
384with a non-zero exit status.
385The blocking size used in the archive volume where writing starts
386will continue to be used for the remainder of that archive volume.
387.Pp
388.Em Warning :
389Many storage devices are not able to support the operations necessary
390to perform an append operation.
391Any attempt to append to an archive stored on such a device may damage the
392archive or have other unpredictable results.
393Tape drives in particular are more likely to not support an append operation.
394An archive stored in a regular file system file or on a disk device will
395usually support an append operation.
396.It Fl b Ar blocksize
397When
398.Em writing
399an archive,
400block the output at a positive decimal integer number of
401bytes per write to the archive file.
402The
403.Ar blocksize
404must be a multiple of 512 bytes with a maximum of 64512 bytes.
405Archives larger than 32256 bytes violate the
406.Tn POSIX
407standard and will not be portable to all systems.
408A
409.Ar blocksize
410can end with
411.Li k
412or
413.Li b
414to specify multiplication by 1024 (1K) or 512, respectively.
415A pair of
416.Ar blocksizes
417can be separated by
418.Li x
419to indicate a product.
420A specific archive device may impose additional restrictions on the size
421of blocking it will support.
422When blocking is not specified, the default
423.Ar blocksize
424is dependent on the specific archive format being used (see the
425.Fl x
426option).
427.It Fl c
428Match all file or archive members
429.Em except
430those specified by the
431.Ar pattern
432and
433.Ar file
434operands.
435.It Fl d
436Cause files of type directory being copied or archived, or archive members of
437type directory being extracted, to match only the directory file or archive
438member and not the file hierarchy rooted at the directory.
439.It Fl f Ar archive
440Specify
441.Ar archive
442as the pathname of the input or output archive, overriding the default
443.Dv standard input
444(for
445.Em list
446and
447.Em read )
448or
449.Dv standard output
450(for
451.Em write ) .
452A single archive may span multiple files and different archive devices.
453When required,
454.Nm
455will prompt for the pathname of the file or device of the next volume in the
456archive.
457.It Fl i
458Interactively rename files or archive members.
459For each archive member matching a
460.Ar pattern
461operand or each file matching a
462.Ar file
463operand,
464.Nm
465will prompt to
466.Pa /dev/tty
467giving the name of the file, its file mode and its modification time.
468.Nm Pax
469will then read a line from
470.Pa /dev/tty .
471If this line is blank, the file or archive member is skipped.
472If this line consists of a single period, the
473file or archive member is processed with no modification to its name.
474Otherwise, its name is replaced with the contents of the line.
475.Nm Pax
476will immediately exit with a non-zero exit status if
477.Dv <EOF>
478is encountered when reading a response or if
479.Pa /dev/tty
480cannot be opened for reading and writing.
481.It Fl k
482Do not overwrite existing files.
483.It Fl l
484Link files.
485(The letter ell).
486In the
487.Em copy
488mode
489.Pq Fl r w ,
490hard links are made between the source and destination file hierarchies
491whenever possible.
492.It Fl n
493Select the first archive member that matches each
494.Ar pattern
495operand.
496No more than one archive member is matched for each
497.Ar pattern .
498When members of type directory are matched, the file hierarchy rooted at that
499directory is also matched (unless
500.Fl d
501is also specified).
502.It Fl o Ar options
503Information to modify the algorithm for extracting or writing archive files
504which is specific to the archive format specified by
505.Fl x .
506In general,
507.Ar options
508take the form:
509.Cm name=value
510.It Fl p Ar string
511Specify one or more file characteristic options (privileges).
512The
513.Ar string
514option-argument is a string specifying file characteristics to be retained or
515discarded on extraction.
516The string consists of the specification characters
517.Cm a , e , m , o ,
518and
519.Cm p .
520Multiple characteristics can be concatenated within the same string
521and multiple
522.Fl p
523options can be specified.
524The meaning of the specification characters are as follows:
525.Bl -tag -width 2n
526.It Cm a
527Do not preserve file access times.
528By default, file access times are preserved whenever possible.
529.It Cm e
530.Sq Preserve everything ,
531the user ID, group ID, file mode bits,
532file access time, and file modification time.
533This is intended to be used by
534.Em root ,
535someone with all the appropriate privileges, in order to preserve all
536aspects of the files as they are recorded in the archive.
537The
538.Cm e
539flag is the sum of the
540.Cm o
541and
542.Cm p
543flags.
544.It Cm m
545Do not preserve file modification times.
546By default, file modification times are preserved whenever possible.
547.It Cm o
548Preserve the user ID and group ID.
549.It Cm p
550.Sq Preserve
551the file mode bits.
552This intended to be used by a
553.Em user
554with regular privileges who wants to preserve all aspects of the file other
555than the ownership.
556The file times are preserved by default, but two other flags are offered to
557disable this and use the time of extraction instead.
558.El
559.Pp
560In the preceding list,
561.Sq preserve
562indicates that an attribute stored in the archive is given to the
563extracted file, subject to the permissions of the invoking
564process.
565Otherwise the attribute of the extracted file is determined as
566part of the normal file creation action.
567If neither the
568.Cm e
569nor the
570.Cm o
571specification character is specified, or the user ID and group ID are not
572preserved for any reason,
573.Nm
574will not set the
575.Dv S_ISUID
576.Em ( setuid )
577and
578.Dv S_ISGID
579.Em ( setgid )
580bits of the file mode.
581If the preservation of any of these items fails for any reason,
582.Nm
583will write a diagnostic message to
584.Dv standard error .
585Failure to preserve these items will affect the final exit status,
586but will not cause the extracted file to be deleted.
587If the file characteristic letters in any of the string option-arguments are
588duplicated or conflict with each other, the one(s) given last will take
589precedence.
590For example, if
591.Dl Fl p Ar eme
592is specified, file modification times are still preserved.
593.It Fl s Ar replstr
594Modify the file or archive member names specified by the
595.Ar pattern
596or
597.Ar file
598operands according to the substitution expression
599.Ar replstr ,
600using the syntax of the
601.Xr ed 1
602utility regular expressions.
603The format of these regular expressions are:
604.Dl /old/new/[gp]
605As in
606.Xr ed 1 ,
607.Cm old
608is a basic regular expression and
609.Cm new
610can contain an ampersand (&), \\n (where n is a digit) back-references,
611or subexpression matching.
612The
613.Cm old
614string may also contain
615.Dv <newline>
616characters.
617Any non-null character can be used as a delimiter (/ is shown here).
618Multiple
619.Fl s
620expressions can be specified.
621The expressions are applied in the order they are specified on the
622command line, terminating with the first successful substitution.
623The optional trailing
624.Cm g
625continues to apply the substitution expression to the pathname substring
626which starts with the first character following the end of the last successful
627substitution.
628The first unsuccessful substitution stops the operation of the
629.Cm g
630option.
631The optional trailing
632.Cm p
633will cause the final result of a successful substitution to be written to
634.Dv standard error
635in the following format:
636.Dl <original pathname> >> <new pathname>
637File or archive member names that substitute to the empty string
638are not selected and will be skipped.
639.It Fl t
640Reset the access times of any file or directory read or accessed by
641.Nm
642to be the same as they were before being read or accessed by
643.Nm .
644.It Fl u
645Ignore files that are older (having a less recent file modification time)
646than a pre-existing file or archive member with the same name.
647During
648.Em read ,
649an archive member with the same name as a file in the file system will be
650extracted if the archive member is newer than the file.
651During
652.Em write ,
653a file system member with the same name as an archive member will be
654written to the archive if it is newer than the archive member.
655During
656.Em copy ,
657the file in the destination hierarchy is replaced by the file in the source
658hierarchy or by a link to the file in the source hierarchy if the file in
659the source hierarchy is newer.
660.It Fl v
661During a
662.Em list
663operation, produce a verbose table of contents using the format of the
664.Xr ls 1
665utility with the
666.Fl l
667option.
668For pathnames representing a hard link to a previous member of the archive,
669the output has the format:
670.Dl <ls -l listing> == <link name>
671For pathnames representing a symbolic link, the output has the format:
672.Dl <ls -l listing> => <link name>
673Where <ls -l listing> is the output format specified by the
674.Xr ls 1
675utility when used with the
676.Fl l
677option.
678Otherwise for all the other operational modes
679.Em ( read , write ,
680and
681.Em copy ) ,
682pathnames are written and flushed to
683.Dv standard error
684without a trailing
685.Dv <newline>
686as soon as processing begins on that file or
687archive member.
688The trailing
689.Dv <newline> ,
690is not buffered, and is written only after the file has been read or written.
691.It Fl x Ar format
692Specify the output archive format, with the default format being
693.Ar ustar .
694.Nm Pax
695currently supports the following formats:
696.Bl -tag -width "sv4cpio"
697.It Ar cpio
698The extended cpio interchange format specified in the
699.St -p1003.2
700standard.
701The default blocksize for this format is 5120 bytes.
702Inode and device information about a file (used for detecting file hard links
703by this format) which may be truncated by this format is detected by
704.Nm
705and is repaired.
706.It Ar bcpio
707The old binary cpio format.
708The default blocksize for this format is 5120 bytes.
709This format is not very portable and should not be used when other formats
710are available.
711Inode and device information about a file (used for detecting file hard links
712by this format) which may be truncated by this format is detected by
713.Nm
714and is repaired.
715.It Ar sv4cpio
716The System V release 4 cpio.
717The default blocksize for this format is 5120 bytes.
718Inode and device information about a file (used for detecting file hard links
719by this format) which may be truncated by this format is detected by
720.Nm
721and is repaired.
722.It Ar sv4crc
723The System V release 4 cpio with file crc checksums.
724The default blocksize for this format is 5120 bytes.
725Inode and device information about a file (used for detecting file hard links
726by this format) which may be truncated by this format is detected by
727.Nm
728and is repaired.
729.It Ar tar
730The old
731.Bx
732tar format as found in
733.Bx 4.3 .
734The default blocksize for this format is 10240 bytes.
735Pathnames stored by this format must be 100 characters or less in length.
736Only
737.Em regular
738files,
739.Em  hard links , soft links ,
740and
741.Em  directories
742will be archived (other file system types are not supported).
743For backwards compatibility with even older tar formats, a
744.Fl o
745option can be used when writing an archive to omit the storage of directories.
746This option takes the form:
747.Dl Fl o Cm write_opt=nodir
748.It Ar ustar
749The extended tar interchange format specified in the
750.St -p1003.2
751standard.
752The default blocksize for this format is 10240 bytes.
753Pathnames stored by this format must be 250 characters or less in length.
754.El
755.Pp
756.Nm Pax
757will detect and report any file that it is unable to store or extract
758as the result of any specific archive format restrictions.
759The individual archive formats may impose additional restrictions on use.
760Typical archive format restrictions include (but are not limited to):
761file pathname length, file size, link pathname length and the type of the file.
762.It Fl z
763Use
764.Xr gzip 1
765to compress (decompress) the archive while writing (reading).
766Incompatible with
767.Fl a .
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 '\\' 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 P
846Do not follow symbolic links, perform a physical file system traversal.
847This is the default mode.
848.It Fl T Ar [from_date][,to_date][/[c][m]]
849Allow files to be selected based on a file modification or inode change
850time falling within a specified time range of
851.Ar from_date
852to
853.Ar to_date
854(the dates are inclusive).
855If only a
856.Ar from_date
857is supplied, all files with a modification or inode change time
858equal to or younger are selected.
859If only a
860.Ar to_date
861is supplied, all files with a modification or inode change time
862equal to or older will be selected.
863When the
864.Ar from_date
865is equal to the
866.Ar to_date ,
867only files with a modification or inode change time of exactly that
868time will be selected.
869.Pp
870When
871.Nm
872is in the
873.Em write
874or
875.Em copy
876mode, the optional trailing field
877.Ar [c][m]
878can be used to determine which file time (inode change, file modification or
879both) are used in the comparison.
880If neither is specified, the default is to use file modification time only.
881The
882.Ar m
883specifies the comparison of file modification time (the time when
884the file was last written).
885The
886.Ar c
887specifies the comparison of inode change time (the time when the file
888inode was last changed; e.g. a change of owner, group, mode, etc).
889When
890.Ar c
891and
892.Ar m
893are both specified, then the modification and inode change times are
894both compared.
895The inode change time comparison is useful in selecting files whose
896attributes were recently changed or selecting files which were recently
897created and had their modification time reset to an older time (as what
898happens when a file is extracted from an archive and the modification time
899is preserved).
900Time comparisons using both file times is useful when
901.Nm
902is used to create a time based incremental archive (only files that were
903changed during a specified time range will be archived).
904.Pp
905A time range is made up of six different fields and each field must contain two
906digits.
907The format is:
908.Dl [yy[mm[dd[hh]]]]mm[.ss]
909Where
910.Cm yy
911is the last two digits of the year,
912the first
913.Cm mm
914is the month (from 01 to 12),
915.Cm dd
916is the day of the month (from 01 to 31),
917.Cm hh
918is the hour of the day (from 00 to 23),
919the second
920.Cm mm
921is the minute (from 00 to 59),
922and
923.Cm ss
924is the seconds (from 00 to 59).
925The minute field
926.Cm mm
927is required, while the other fields are optional and must be added in the
928following order:
929.Dl Cm hh , dd , mm , yy .
930The
931.Cm ss
932field may be added independently of the other fields.
933Time ranges are relative to the current time, so
934.Dl Fl T Ar 1234/cm
935would select all files with a modification or inode change time
936of 12:34 PM today or later.
937Multiple
938.Fl T
939time range can be supplied and checking stops with the first match.
940.It Fl U Ar user
941Select a file based on its
942.Ar user
943name, or when starting with a
944.Cm # ,
945a numeric uid.
946A '\\' can be used to escape the
947.Cm # .
948Multiple
949.Fl U
950options may be supplied and checking stops with the first match.
951.It Fl X
952When traversing the file hierarchy specified by a pathname,
953do not descend into directories that have a different device ID.
954See the
955.Li st_dev
956field as described in
957.Xr stat 2
958for more information about device ID's.
959.It Fl Y
960This option is the same as the
961.Fl D
962option, except that the inode change time is checked using the
963pathname created after all the file name modifications have completed.
964.It Fl Z
965This option is the same as the
966.Fl u
967option, except that the modification time is checked using the
968pathname created after all the file name modifications have completed.
969.El
970.Pp
971The options that operate on the names of files or archive members
972.Fl ( c ,
973.Fl i ,
974.Fl n ,
975.Fl s ,
976.Fl u ,
977.Fl v ,
978.Fl D ,
979.Fl G ,
980.Fl T ,
981.Fl U ,
982.Fl Y ,
983and
984.Fl Z )
985interact as follows.
986.Pp
987When extracting files during a
988.Em read
989operation, archive members are
990.Sq selected ,
991based only on the user specified pattern operands as modified by the
992.Fl c ,
993.Fl n ,
994.Fl u ,
995.Fl D ,
996.Fl G ,
997.Fl T ,
998.Fl U
999options.
1000Then any
1001.Fl s
1002and
1003.Fl i
1004options will modify in that order, the names of these selected files.
1005Then the
1006.Fl Y
1007and
1008.Fl Z
1009options will be applied based on the final pathname.
1010Finally the
1011.Fl v
1012option will write the names resulting from these modifications.
1013.Pp
1014When archiving files during a
1015.Em write
1016operation, or copying files during a
1017.Em copy
1018operation, archive members are
1019.Sq selected ,
1020based only on the user specified pathnames as modified by the
1021.Fl n ,
1022.Fl u ,
1023.Fl D ,
1024.Fl G ,
1025.Fl T ,
1026and
1027.Fl U
1028options (the
1029.Fl D
1030option only applies during a copy operation).
1031Then any
1032.Fl s
1033and
1034.Fl i
1035options will modify in that order, the names of these selected files.
1036Then during a
1037.Em copy
1038operation the
1039.Fl Y
1040and the
1041.Fl Z
1042options will be applied based on the final pathname.
1043Finally the
1044.Fl v
1045option will write the names resulting from these modifications.
1046.Pp
1047When one or both of the
1048.Fl u
1049or
1050.Fl D
1051options are specified along with the
1052.Fl n
1053option, a file is not considered selected unless it is newer
1054than the file to which it is compared.
1055.Sh EXAMPLES
1056The command:
1057.Dl "pax -w -f /dev/rst0 ."
1058copies the contents of the current directory to the device
1059.Pa /dev/rst0 .
1060.Pp
1061The command:
1062.Dl pax -v -f filename
1063gives the verbose table of contents for an archive stored in
1064.Pa filename .
1065.Pp
1066The following commands:
1067.Dl mkdir /tmp/foo
1068.Dl cd /tmp/bar
1069.Dl pax -rw .\ /tmp/foo
1070will copy the entire
1071.Pa /tmp/bar
1072directory hierarchy to
1073.Pa /tmp/foo .
1074.Pp
1075The command:
1076.Dl pax -r -s ',^//*usr//*,,' -f a.pax
1077reads the archive
1078.Pa a.pax ,
1079with all files rooted in ``/usr'' into the archive extracted relative to the
1080current directory.
1081.Pp
1082The command:
1083.Dl pax -rw -i .\ dest_dir
1084can be used to interactively select the files to copy from the current
1085directory to
1086.Pa dest_dir .
1087.Pp
1088The command:
1089.Dl pax -r -pe -U root -G bin -f a.pax
1090will extract all files from the archive
1091.Pa a.pax
1092which are owned by
1093.Em root
1094with group
1095.Em bin
1096and will preserve all file permissions.
1097.Pp
1098The command:
1099.Dl pax -r -w -v -Y -Z home /backup
1100will update (and list) only those files in the destination directory
1101.Pa /backup
1102which are older (less recent inode change or file modification times) than
1103files with the same name found in the source file tree
1104.Pa home .
1105.Sh STANDARDS
1106The
1107.Nm
1108utility is a superset of the
1109.St -p1003.2
1110standard.
1111The options
1112.Fl z ,
1113.Fl B ,
1114.Fl D ,
1115.Fl E ,
1116.Fl G ,
1117.Fl H ,
1118.Fl L ,
1119.Fl P ,
1120.Fl T ,
1121.Fl U ,
1122.Fl Y ,
1123.Fl Z ,
1124the archive formats
1125.Ar bcpio ,
1126.Ar sv4cpio ,
1127.Ar sv4crc ,
1128.Ar tar ,
1129and the flawed archive handling during
1130.Ar list
1131and
1132.Ar read
1133operations are extensions to the
1134.Tn POSIX
1135standard.
1136.Sh SEE ALSO
1137.Xr cpio 1 ,
1138.Xr tar 1
1139.Sh HISTORY
1140The
1141.Nm
1142utility appeared in
1143.Bx 4.4 .
1144.Sh AUTHORS
1145.An Keith Muller
1146at the University of California, San Diego
1147.Sh DIAGNOSTICS
1148.Nm Pax
1149will exit with one of the following values:
1150.Bl -tag -width 2n
1151.It 0
1152All files were processed successfully.
1153.It 1
1154An error occurred.
1155.El
1156.Pp
1157Whenever
1158.Nm
1159cannot create a file or a link when reading an archive or cannot
1160find a file when writing an archive, or cannot preserve the user ID,
1161group ID, or file mode when the
1162.Fl p
1163option is specified, a diagnostic message is written to
1164.Dv standard error
1165and a non-zero exit status will be returned, but processing will continue.
1166In the case where pax cannot create a link to a file,
1167.Nm
1168will not create a second copy of the file.
1169.Pp
1170If the extraction of a file from an archive is prematurely terminated by
1171a signal or error,
1172.Nm
1173may have only partially extracted a file the user wanted.
1174Additionally, the file modes of extracted files and directories
1175may have incorrect file bits, and the modification and access times may be
1176wrong.
1177.Pp
1178If the creation of an archive is prematurely terminated by a signal or error,
1179.Nm
1180may have only partially created the archive which may violate the specific
1181archive format specification.
1182.Pp
1183If while doing a
1184.Em copy ,
1185.Nm
1186detects a file is about to overwrite itself, the file is not copied,
1187a diagnostic message is written to
1188.Dv standard error
1189and when
1190.Nm
1191completes it will exit with a non-zero exit status.
1192