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.\" $FreeBSD$

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.Dd September 16, 2014

.Dt CPIO 1

.Os

.Sh NAME

.Nm cpio

.Nd copy files to and from archives

.Sh SYNOPSIS

.Nm

.Fl i

.Op Ar options

.Op Ar pattern ...

.Op Ar < archive

.Nm

.Fl o

.Op Ar options

.Ar < name-list

.Op Ar > archive

.Nm

.Fl p

.Op Ar options

.Ar dest-dir

.Ar < name-list

.Sh DESCRIPTION

.Nm

copies files between archives and directories.

This implementation can extract from tar, pax, cpio, zip, jar, ar,

and ISO 9660 cdrom images and can create tar, pax, cpio, ar,

and shar archives.

.Pp

The first option to

.Nm

is a mode indicator from the following list:

.Bl -tag -compact -width indent

.It Fl i

Input.

Read an archive from standard input (unless overridden) and extract the

contents to disk or (if the

.Fl t

option is specified)

list the contents to standard output.

If one or more file patterns are specified, only files matching

one of the patterns will be extracted.

.It Fl o

Output.

Read a list of filenames from standard input and produce a new archive

on standard output (unless overridden) containing the specified items.

.It Fl p

Pass-through.

Read a list of filenames from standard input and copy the files to the

specified directory.

.El

.Pp

.Sh OPTIONS

Unless specifically stated otherwise, options are applicable in

all operating modes.

.Bl -tag -width indent

.It Fl 0 , Fl Fl null

Read filenames separated by NUL characters instead of newlines.

This is necessary if any of the filenames being read might contain newlines.

.It Fl A

(o mode only)

Append to the specified archive.

(Not yet implemented.)

.It Fl a

(o and p modes)

Reset access times on files after they are read.

.It Fl B

(o mode only)

Block output to records of 5120 bytes.

.It Fl C Ar size

(o mode only)

Block output to records of

.Ar size

bytes.

.It Fl c

(o mode only)

Use the old POSIX portable character format.

Equivalent to

.Fl Fl format Ar odc .

.It Fl d , Fl Fl make-directories

(i and p modes)

Create directories as necessary.

.It Fl E Ar file

(i mode only)

Read list of file name patterns from

.Ar file

to list and extract.

.It Fl F Ar file , Fl Fl file Ar file

Read archive from or write archive to

.Ar file .

.It Fl f Ar pattern

(i mode only)

Ignore files that match

.Ar pattern .

.It Fl H Ar format , Fl Fl format Ar format

(o mode only)

Produce the output archive in the specified format.

Supported formats include:

.Pp

.Bl -tag -width "iso9660" -compact

.It Ar cpio

Synonym for

.Ar odc .

.It Ar newc

The SVR4 portable cpio format.

.It Ar odc

The old POSIX.1 portable octet-oriented cpio format.

.It Ar pax

The POSIX.1 pax format, an extension of the ustar format.

.It Ar ustar

The POSIX.1 tar format.

.El

.Pp

The default format is

.Ar odc .

See

.Xr libarchive-formats 5

for more complete information about the

formats currently supported by the underlying

.Xr libarchive 3

library.

.It Fl h , Fl Fl help

Print usage information.

.It Fl I Ar file

Read archive from

.Ar file .

.It Fl i , Fl Fl extract

Input mode.

See above for description.

.It Fl Fl insecure

(i and p mode only)

Disable security checks during extraction or copying.

This allows extraction via symbolic links, absolute paths,

and path names containing

.Sq ..

in the name.

.It Fl J , Fl Fl xz

(o mode only)

Compress the file with xz-compatible compression before writing it.

In input mode, this option is ignored; xz compression is recognized

automatically on input.

.It Fl j

Synonym for

.Fl y .

.It Fl L

(o and p modes)

All symbolic links will be followed.

Normally, symbolic links are archived and copied as symbolic links.

With this option, the target of the link will be archived or copied instead.

.It Fl l , Fl Fl link

(p mode only)

Create links from the target directory to the original files,

instead of copying.

.It Fl Fl lrzip

(o mode only)

Compress the resulting archive with

.Xr lrzip 1 .

In input mode, this option is ignored.

.It Fl Fl lz4

(o mode only)

Compress the archive with lz4-compatible compression before writing it.

In input mode, this option is ignored; lz4 compression is recognized

automatically on input.

.It Fl Fl lzma

(o mode only)

Compress the file with lzma-compatible compression before writing it.

In input mode, this option is ignored; lzma compression is recognized

automatically on input.

.It Fl Fl lzop

(o mode only)

Compress the resulting archive with

.Xr lzop 1 .

In input mode, this option is ignored.

.It Fl Fl passphrase Ar passphrase

The

.Pa passphrase

is used to extract or create an encrypted archive.

Currently, zip is only a format that

.Nm

can handle encrypted archives.

You shouldn't use this option unless you realize how insecure

use of this option is.

.It Fl m , Fl Fl preserve-modification-time

(i and p modes)

Set file modification time on created files to match

those in the source.

.It Fl n , Fl Fl numeric-uid-gid

(i mode, only with

.Fl t )

Display numeric uid and gid.

By default,

.Nm

displays the user and group names when they are provided in the

archive, or looks up the user and group names in the system

password database.

.It Fl Fl no-preserve-owner

(i mode only)

Do not attempt to restore file ownership.

This is the default when run by non-root users.

.It Fl O Ar file

Write archive to

.Ar file .

.It Fl o , Fl Fl create

Output mode.

See above for description.

.It Fl p , Fl Fl pass-through

Pass-through mode.

See above for description.

.It Fl Fl preserve-owner

(i mode only)

Restore file ownership.

This is the default when run by the root user.

.It Fl Fl quiet

Suppress unnecessary messages.

.It Fl R Oo user Oc Ns Oo : Oc Ns Oo group Oc , Fl Fl owner Oo user Oc Ns Oo : Oc Ns Oo group Oc

Set the owner and/or group on files in the output.

If group is specified with no user

(for example,

.Fl R Ar :wheel )

then the group will be set but not the user.

If the user is specified with a trailing colon and no group

(for example,

.Fl R Ar root: )

then the group will be set to the user's default group.

If the user is specified with no trailing colon, then

the user will be set but not the group.

In

.Fl i

and

.Fl p

modes, this option can only be used by the super-user.

(For compatibility, a period can be used in place of the colon.)

.It Fl r

(All modes.)

Rename files interactively.

For each file, a prompt is written to

.Pa /dev/tty

containing the name of the file and a line is read from

.Pa /dev/tty .

If the line read is blank, the file is skipped.

If the line contains a single period, the file is processed normally.

Otherwise, the line is taken to be the new name of the file.

.It Fl t , Fl Fl list

(i mode only)

List the contents of the archive to stdout;

do not restore the contents to disk.

.It Fl u , Fl Fl unconditional

(i and p modes)

Unconditionally overwrite existing files.

Ordinarily, an older file will not overwrite a newer file on disk.

.It Fl V , Fl Fl dot

Print a dot to stderr for each file as it is processed.

Superseded by

.Fl v .

.It Fl v , Fl Fl verbose

Print the name of each file to stderr as it is processed.

With

.Fl t ,

provide a detailed listing of each file.

.It Fl Fl version

Print the program version information and exit.

.It Fl y

(o mode only)

Compress the archive with bzip2-compatible compression before writing it.

In input mode, this option is ignored;

bzip2 compression is recognized automatically on input.

.It Fl Z

(o mode only)

Compress the archive with compress-compatible compression before writing it.

In input mode, this option is ignored;

compression is recognized automatically on input.

.It Fl z

(o mode only)

Compress the archive with gzip-compatible compression before writing it.

In input mode, this option is ignored;

gzip compression is recognized automatically on input.

.El

.Sh EXIT STATUS

.Ex -std

.Sh ENVIRONMENT

The following environment variables affect the execution of

.Nm :

.Bl -tag -width ".Ev BLOCKSIZE"

.It Ev LANG

The locale to use.

See

.Xr environ 7

for more information.

.It Ev TZ

The timezone to use when displaying dates.

See

.Xr environ 7

for more information.

.El

.Sh EXAMPLES

The

.Nm

command is traditionally used to copy file hierarchies in conjunction

with the

.Xr find 1

command.

The first example here simply copies all files from

.Pa src

to

.Pa dest :

.Dl Nm find Pa src | Nm Fl pmud Pa dest

.Pp

By carefully selecting options to the

.Xr find 1

command and combining it with other standard utilities,

it is possible to exercise very fine control over which files are copied.

This next example copies files from

.Pa src

to

.Pa dest

that are more than 2 days old and whose names match a particular pattern:

.Dl Nm find Pa src Fl mtime Ar +2 | Nm grep foo[bar] | Nm Fl pdmu Pa dest

.Pp

This example copies files from

.Pa src

to

.Pa dest

that are more than 2 days old and which contain the word

.Do foobar Dc :

.Dl Nm find Pa src Fl mtime Ar +2 | Nm xargs Nm grep -l foobar | Nm Fl pdmu Pa dest

.Sh COMPATIBILITY

The mode options i, o, and p and the options

a, B, c, d, f, l, m, r, t, u, and v comply with SUSv2.

.Pp

The old POSIX.1 standard specified that only

.Fl i ,

.Fl o ,

and

.Fl p

were interpreted as command-line options.

Each took a single argument of a list of modifier

characters.

For example, the standard syntax allows

.Fl imu

but does not support

.Fl miu

or

.Fl i Fl m Fl u ,

since

.Ar m

and

.Ar u

are only modifiers to

.Fl i ,

they are not command-line options in their own right.

The syntax supported by this implementation is backwards-compatible

with the standard.

For best compatibility, scripts should limit themselves to the

standard syntax.

.Sh SEE ALSO

.Xr bzip2 1 ,

.Xr tar 1 ,

.Xr gzip 1 ,

.Xr mt 1 ,

.Xr pax 1 ,

.Xr libarchive 3 ,

.Xr cpio 5 ,

.Xr libarchive-formats 5 ,

.Xr tar 5

.Sh STANDARDS

There is no current POSIX standard for the cpio command; it appeared

in

.St -p1003.1-96

but was dropped from

.St -p1003.1-2001 .

.Pp

The cpio, ustar, and pax interchange file formats are defined by

.St -p1003.1-2001

for the pax command.

.Sh HISTORY

The original

.Nm cpio

and

.Nm find

utilities were written by Dick Haight

while working in AT&T's Unix Support Group.

They first appeared in 1977 in PWB/UNIX 1.0, the

.Dq Programmer's Work Bench

system developed for use within AT&T.

They were first released outside of AT&T as part of System III Unix in 1981.

As a result,

.Nm cpio

actually predates

.Nm tar ,

even though it was not well-known outside of AT&T until some time later.

.Pp

This is a complete re-implementation based on the

.Xr libarchive 3

library.

.Sh BUGS

The cpio archive format has several basic limitations:

It does not store user and group names, only numbers.

As a result, it cannot be reliably used to transfer

files between systems with dissimilar user and group numbering.

Older cpio formats limit the user and group numbers to

16 or 18 bits, which is insufficient for modern systems.

The cpio archive formats cannot support files over 4 gigabytes,

except for the

.Dq odc

variant, which can support files up to 8 gigabytes.