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.\" $Id: pax.1,v 1.2 89/02/12 10:08:47 mark Exp $

.TH PAX 1 "USENIX Association" ""

.SH NAME

pax \- portable archive exchange 

.SH SYNOPSIS

.TP \w'\fBpax\fR\ 'u

.B pax

.RB [ \-cimopuvy ]

.RI "[\fB\-f\fR" " archive" ]

.RI "[\fB\-s\fR" " replstr" ]

.RI "[\fB\-t\fR" " device" ] 

.RI [ pattern... ]

.TP \w'\fBpax\ \-r\fR\ 'u

.B "pax\ \-r"

.RB [ \-cimnopuvy ]

.RI "[\fB\-f\fR" " archive" ]

.RI "[\fB\-s\fR" " replstr" ] 

.RI "[\fB\-t\fR" " device" ] 

.RI [ pattern... ]

.TP \w'\fBpax\ \-w\fR\ 'u

.B "pax\ \-w"

.RB [ \-adimuvy ] 

.RI "[\fB\-b\fR" " blocking" ]

.RI "[\fB\-f\fR" " archive" ] 

.RI "[\fB\-s\fR" " replstr" ] 

.RI "[\fB\-t\fR" " device" ] 

.RI "[\fB\-x\fR" " format" ]

.RI [ pathname... ]

.TP \w'\fBpax\ \-rw\fR\ 'u

.B "pax\ \-rw"

.RB [ \-ilmopuvy ] 

.RI "[\fB\-s\fR" " replstr" ] 

.RI [ pathname... ]

directory

.SH DESCRIPTION

.I Pax 

reads and writes archive files which conform to the 

.B "Archive/Interchange File Format" 

specified in 

.IR "IEEE Std. 1003.1-1988" .

.I Pax

can also read, but not write, a number of other file formats

in addition to those specified in the 

.B "Archive/Interchange File Format"

description.

Support for these traditional file formats, such as V7 

.I "tar" 

and System V binary 

.I "cpio" 

format archives,

is provided for backward compatibility and to maximize portability.

.PP

.I Pax 

will also support traditional 

.I cpio 

and 

System V

.I tar

interfaces if invoked with the name

"cpio" or "tar" respectively.

See the 

.I cpio(1) 

or 

.I tar(1)

manual pages for more details.

.PP

Combinations of the

.B \-r 

and 

.B \-w

command line arguments specify whether 

.I pax 

will read, write or list the contents of the specified archive,

or move the specified files to another directory.

.PP

The command line arguments are:

.TP .5i

.B \-w

writes the files and directories specified by 

.I pathname

operands to the standard output together with the pathname and status 

information prescribed by the archive format used.

A directory

.I pathname

operand refers to the files and (recursively) subdirectories of that 

directory.

If no 

.I pathname 

operands are given, then the standard input is read to get a

list of pathnames to copy, one pathname per line.

In this case, only those pathnames appearing on the standard input are

copied.

.TP .5i

.B \-r

.I Pax

reads an archive file from the standard input.

Only files with names that match any of the 

.I pattern

operands are selected for extraction.

The selected files are conditionally created and copied relative to the

current directory tree, subject to the options described below.

By default, the owner and group of selected files will be that of the

invoking process, and the permissions and modification times will be the

sames as those in the archive.

.RS .5i

.PP

The supported archive formats are automatically detected on input.

The default output format is 

.IR ustar ,

but may be overridden by the 

.B \-x

.I format

option described below.

.RE

.TP .5i

.B \-rw

.I Pax 

reads the files and directories named in the

.I pathname

operands and copies them to the destination 

.IR directory .

A directory

.I pathname 

operand refers to the files and (recursively) subdirectories of that

directory.

If no 

.I pathname

operands are given, the standard input is read to get a list of pathnames

to copy, one pathname per line.

In this case, only those pathnames appearing on the standard input are

copied.

The directory named by the 

.I directory

operand must exist and have the proper permissions before the copy can

occur.

.PP

If neither the

.BR \-r " or " \-w 

options are given, then 

.I pax

will list the contents of the specified archive.

In this mode, 

.I pax 

lists normal files one per line, hard link pathnames as

.sp

.RS 1i

.IR pathname " == " linkname

.RE

.sp

and symbolic link pathnames (if supported by the implementation) as

.sp

.RS 1i

.IR pathname " -> " linkname

.RE

.sp

where 

.I pathname

is the name of the file being extracted, and

.I linkname

is the name of a file which appeared earlier in the archive.

.PP

If the 

.B \-v

option is specified, then 

.I pax 

list normal pathnames in the same format used by the 

.I ls

utility with the

.B \-l

option.

Hard links are shown as

.sp

.RS 1i

.IR "<ls -l listing>" " == " linkname

.RE

.sp

and symbolic links (if supported) are shown as

.sp

.RS 1i

.IR "<ls -l listing>" " -> " linkname

.RE

.sp 

.PP

.I Pax 

is capable of reading and writing archives which span multiple physical 

volumes.

Upon detecting an end of medium on an archive which is not yet completed,

.I pax 

will prompt the user for the next volume of the archive and will allow the 

user to specify the location of the next volume.

.SS Options

The following options are available:

.TP 1i

.B \-a

The files specified by

.I pathname

are appended to the specified archive.

.TP 1i

.BI \-b " blocking"

Block the output at

.I blocking

bytes per write to the archive file.

A 

.B k

suffix multiplies 

.I blocking 

by 1024, a

.B b 

suffix multiplies 

.I blocking 

by 512 and a 

.B m

suffix multiplies 

.I blocking 

by 1048576 (1 megabyte).

For machines with 16-bit int's (VAXen, XENIX-286, etc.), 

the maximum buffer size is 32k-1.

If not specified,

.I blocking 

is automatically determined on input and is ignored for 

.B \-rw.

.TP 1i

.B \-c

Complement the match sense of the 

.I pattern

operands.

.TP 1i

.B \-d

Intermediate directories not explicitly listed in the archive are not 

created.

This option is ignored unless

the 

.B \-r

option is specified.

.TP 1i

.BI \-f " archive"

The

.I archive

option specifies the pathname of the input or output archive,

overriding the default of standard input for 

.B \-r

or standard output for

.BR \-w .

.TP 1i

.B \-i

Interactively rename files.

Substitutions specified by 

.B \-s

options (described below)

are performed before requesting the new file name from the user.

A file is skipped if an empty line is entered and

.I pax

exits with an exit status of 0 if 

.B EOF 

is encountered.

.TP 1i

.B \-l

Files are linked rather than copied when possible.

.TP 1i

.B \-m

File modification times are not retained.

.TP 1i

.B \-n

When 

.B \-r

is specified, but

.B \-w

is not, the 

.I pattern

arguments are treated as ordinary file names.

Only the first occurrence of each of these files in the input archive

is read.

The

.B pax

utility exits with a zero exit status after all files in the list have been

read.

If one or more files in the list is not found,

.B pax

writes a diagnostic to standard error for each of the files and exits with

a non-zero exit status.

the file names are compared before any of the 

.BR \-i ,

.BR \-s ,

or

.B \-y

options are applied.

.TP 1i

.B \-o

Restore file ownership as specified in the archive.

The invoking process must have appropriate privileges to accomplish this.

.TP 1i

.B \-p

Preserve the access time of the input files after they have been copied.

.TP 1i

.BI \-s " replstr"

File names are modified according to the substitution expression using the 

syntax of 

.I "ed(1)"

as shown:

.sp

.RS 2i

-s /\fIold\fR/\fInew\fR/\fB[\fRgp\fB]\fR

.RE

.RS 1i

.PP

Any non null character may be used as a delimiter (a / is used here as an

example).

Multiple 

.B \-s

expressions may be specified; the expressions are applied in the order

specified terminating with the first successful substitution.

The optional trailing 

.B p

causes successful mappings to be listed on standard error.

The optional trailing

.B g

causes the 

.I old 

expression to be replaced each time it occurs in the source string.

Files that substitute to an empty string are ignored both on input and

output.

.RE

.TP 1i

.BI \-t " device"

The

.I device

option argument is an implementation-defined identifier that names the input

or output archive device, overriding the default of standard input for

.B \-r

and standard output for

.BR \-w .

.TP 1i

.B \-u

Copy each file only if it is newer than a pre-existing file with the same

name.

This implies 

.BR \-a .

.TP 1i

.B \-v

List file names as they are encountered.

Produces a verbose table of contents listing on the standard output when both 

.B \-r 

and

.B \-w

are omitted,

otherwise the file names are printed to standard error as they are

encountered in the archive.

.TP 1i

.BI \-x " format"

Specifies the output archive

.IR format .

The input format, which must be one of the following, is automatically

determined when the

.B \-r 

option is used.

The supported formats are:

.RS 1i

.TP 0.75i

.I cpio

The extended 

.I CPIO

interchange format specified in

.B "Extended CPIO Format" in 

.I "IEEE Std. 1003.1-1988."

.TP 0.75i

.I ustar

The extended 

.I TAR

interchange format specified in

.B "Extended TAR Format" in 

.I "IEEE Std. 1003.1-1988."

This is the default archive format.

.RE

.TP 1i

.B \-y

Interactively prompt for the disposition of each file.

Substitutions specified by 

.B \-s

options (described above)

are performed before prompting the user for disposition.

.B EOF

or an input line starting with the character

.B q

caused

.I pax

to exit.

Otherwise, an input line starting with anything other than 

.B y

causes the file to be ignored.

This option cannot be used in conjunction with the 

.B \-i 

option.

.PP

Only the last of multiple 

.B \-f 

or

.B \-t

options take effect.

.PP

When writing to an archive, the

standard input is used as a list of pathnames if no

.I pathname

operands are specified.

The format is one pathname per line.

Otherwise, the standard input is the archive file,

which is formatted according to one of the specifications in

.B "Archive/Interchange File format"

in 

.IR "IEEE Std. 1003.1-1988" ,

or some other implementation-defined format.

.PP

The user ID and group ID of the process, together with the appropriate

privileges, affect the ability of 

.I pax

to restore ownership and permissions attributes of the archived files.

(See 

.I "format-reading utility"

in

.B "Archive/Interchange File Format"

in 

.IR "IEEE Std. 1003.1-1988" ".)"

.PP

The options

.BR \-a ,

.BR \-c ,

.BR \-d ,

.BR \-i ,

.BR \-l ,

.BR \-p ,

.BR \-t ,

.BR \-u ,

and

.BR \-y 

are provided for functional compatibility with the historical

.I cpio

and

.I tar

utilities.

The option defaults were chosen based on the most common usage of these

options, therefore, some of the options have meanings different than

those of the historical commands.

.SS Operands

The following operands are available:

.TP 1i

.I directory

The destination directory pathname for copies when both the

.B \-r

and 

.B \-w

options are specified.

The directory must exist and be writable before the copy or and error

results.

.TP 1i

.I pathname

A file whose contents are used instead of the files named on the standard

input.

When a directory is named, all of its files and (recursively) 

subdirectories

are copied as well.

.TP 1i

.IR pattern 

A

.I pattern

is given in the standard shell pattern matching notation.

The default if no 

.I pattern 

is  specified is

.BR * \,

which selects all files.

.SH EXAMPLES

The following command

.sp

.RS 1i

pax \-w \-f /dev/rmt0 \.

.RE

.sp

copies the contents of the current directory to tape drive 0.

.PP

The commands

.sp

.RS 1i

.RI mkdir " newdir"

.br

.RI cd " olddir"

.br

.RI "pax -rw . " newdir

.RE

.sp

copies the contents of 

.I olddir 

to 

.I newdir .

.PP

The command

.sp

.RS 1i

pax \-r \-s ',//*usr//*,,' -f pax.out

.RE

.sp

reads the archive 

.B pax.out

with all files rooted in "/usr" in the archive extracted

relative to the current directory.

.SH FILES

.TP 1i

/dev/tty

used to prompt the user for information when the

.BR \-i " or " \-y

options are specified. 

.SH "SEE ALSO"

cpio(1), find(1), tar(1), cpio(5), tar(5)

.SH DIAGNOSTICS

.I Pax

will terminate immediately, without processing any 

additional files on the command line or in the archive.

.SH "EXIT CODES"

.I Pax 

will exit with one of the following values:

.IP 0 .5i

All files in the archive were processed successfully.

.IP ">0" .5i

.I Pax 

aborted due to errors encountered during operation.

.SH BUGS

Special permissions may be required to copy or extract special files.

.PP

Device, user ID, and group ID numbers larger than 65535 cause additional

header records to be output.

These records are ignored by some historical version of

.I "cpio(1)"

and

.IR "tar(1)" .

.PP

The archive formats described in

.B "Archive/Interchange File Format" 

have certain restrictions that have

been carried over from historical usage.

For example, there are restrictions on the length of pathnames stored in

the archive.

.PP

When getting an "ls -l" style listing on

.I tar

format archives, link counts are listed as zero since the 

.I ustar

archive format does not keep link count information.

.PP

On 16 bit architectures, the largest buffer size is 32k-1.

This is due, in part, to using integers in the buffer allocation schemes,

however, on many of these machines, it is not possible to allocate blocks

of memory larger than 32k.

.SH COPYRIGHT

Copyright (c) 1989 Mark H. Colburn.  

.br

All rights reserved.

.PP

Redistribution and use in source and binary forms are permitted

provided that the above copyright notice is duplicated in all such 

forms and that any documentation, advertising materials, and other 

materials related to such distribution and use acknowledge that the 

software was developed by Mark H. Colburn and sponsored by The 

USENIX Association. 

.PP

THE SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

.SH AUTHOR

Mark H. Colburn

.br

Minnetech Consulting, Inc.

.br

117 Mackubin Street, Suite 1

.br

St. Paul, MN 55102

.br

mark@jhereg.MN.ORG

.sp 2

Sponsored by

.B "The USENIX Association"

for public distribution.