CPIO(1L) CPIO(1L)
NAME
cpio - copy files to and from archives
__WARNING__
The cpio utility is considered LEGACY based on POSIX specification.
Users are encouraged to use other archiving tools for archive creation.
If you decided to use cpio, you should almost always force cpio to use
the ustar format in copy-out mode by the -H option (cpio -o -H ustar).
This is because the ustar format is well defined in POSIX specification
and thus readable by wide range of other archiving tools (including tar
e.g.).
By default, GNU cpio uses (for historical reasons) the very old binary
format ('bin') which has significant problems nowadays, e.g. with stor-
ing big inode numbers (see the Red Hat bug #952313).
Note also that these days the modern 'pax' archive format should be
considered as the default -- but this format is not implemented in GNU
cpio. You should, again, consider using other archivers (e.g. 'tar
--format=pax').
SYNOPSIS
Copy-out mode
In copy-out mode, cpio copies files into an archive. It reads a list
of filenames, one per line, on the standard input, and writes the ar-
chive onto the standard output. A typical way to generate the list of
filenames is with the find command; you should give find the -depth
option to minimize problems with permissions on directories that are
unreadable. see "Options".
cpio {-o|--create} [-0acvABLV] [-C bytes] [-H format] [-D DIR] [-M mes-
sage] [-O [[user@]host:]archive] [-F [[user@]host:]archive]
[--file=[[user@]host:]archive] [--format=format] [--warning=FLAG]
[--message=message][--null] [--reset-access-time] [--verbose] [--dot]
[--append] [--block-size=blocks] [--dereference] [--io-size=bytes]
[--rsh-command=command] [--license] [--usage] [--help] [--version] <
name-list [> archive]
Copy-in mode
In copy-in mode, cpio copies files out of an archive or lists the ar-
chive contents. It reads the archive from the standard input. Any
non-option command line arguments are shell globbing patterns; only
files in the archive whose names match one or more of those patterns
are copied from the archive. Unlike in the shell, an initial `.' in a
filename does match a wildcard at the start of a pattern, and a `/' in
a filename can match wildcards. If no patterns are given, all files
are extracted. see "Options".
cpio {-i|--extract} [-bcdfmnrtsuvBSV] [-C bytes] [-E file] [-H format]
[-D DIR] [-M message] [-R [user][:.][group]] [-I [[user@]host:]archive]
[-F [[user@]host:]archive] [--file=[[user@]host:]archive] [--make-
directories] [--nonmatching] [--preserve-modification-time] [--numeric-
uid-gid] [--rename] [-t|--list] [--swap-bytes] [--swap] [--dot]
[--warning=FLAG] [--unconditional] [--verbose] [--block-size=blocks]
[--swap-halfwords] [--io-size=bytes] [--pattern-file=file] [--for-
mat=format] [--owner=[user][:.][group]] [--no-preserve-owner] [--mes-
sage=message] [--force-local] [--no-absolute-filenames] [--abso-
lute-filenames] [--sparse] [--only-verify-crc] [--to-stdout] [--quiet]
[--ignore-devno] [--renumber-inodes] [--device-independent] [--repro-
ducible] [--rsh-command=command] [--license] [--usage] [--help] [--ver-
sion] [pattern...] [< archive]
Copy-pass mode
In copy-pass mode, cpio copies files from one directory tree to
another, combining the copy-out and copy-in steps without actually
using an archive. It reads the list of files to copy from the standard
input; the directory into which it will copy them is given as a non-
option argument. see "Options".
cpio {-p|--pass-through} [-0adlmuvLV] [-R [user][:.][group]] [-D DIR]
[--null] [--reset-access-time] [--make-directories] [--link] [--quiet]
[--preserve-modification-time] [--unconditional] [--verbose] [--dot]
[--warning=FLAG] [--dereference] [--owner=[user][:.][group]] [--no-pre-
serve-owner] [--sparse] [--license] [--usage] [--help] [--version]
destination-directory < name-list
DESCRIPTION
GNU cpio is a tool for creating and extracting archives, or copying
files from one place to another. It handles a number of cpio formats
as well as reading and writing tar files.
Following archive formats are supported: binary, old ASCII, new ASCII,
crc, HPUX binary, HPUX old ASCII, old tar, and POSIX.1 tar. The tar
format is provided for compatibility with the tar program. By default,
cpio creates binary format archives, for compatibility with older cpio
programs. When extracting from archives, cpio automatically recognizes
which kind of archive it is reading and can read archives created on
machines with a different byte-order.
Main operation mode:
-i, --extract
Extract files from an archive (run in copy-in mode)
-o, --create
Create the archive (run in copy-out mode)
-p, --pass-through
Run in copy-pass mode
-t, --list
Print a table of contents of the input
Operation modifiers valid in any mode:
--block-size=BLOCK-SIZE
Set the I/O block size to BLOCK-SIZE * 512 bytes
-B Set the I/O block size to 5120 bytes. Initially the block size
is 512 bytes.
-c Identical to "-H newc", use the new (SVR4) portable format. If
you wish the old portable (ASCII) archive format, use "-H odc"
instead.
-C, --io-size=NUMBER
Set the I/O block size to the given NUMBER of bytes
-D, --directory=DIR
Change to directory DIR
--force-local
With -F, -I, or -O, take the archive file name to be a local
file even if it contains a colon, which would ordinarily indi-
cate a remote host name.
-H, --format=FORMAT
Use given archive FORMAT. The valid formats are listed below;
the same names are also recognized in all-caps. The default in
copy-in mode is to automatically detect the archive format, and
in copy-out mode is `bin'.
`bin' The obsolete binary format.
`odc' The old (POSIX.1) portable format.
`newc' The new (SVR4) portable format, which supports file systems hav-
ing more than 65536 i-nodes.
`crc' The new (SVR4) portable format with a checksum (Sum32) added.
`tar' The old tar format.
`ustar'
The POSIX.1 tar format. Also recognizes GNU tar archives, which
are similar but not identical.
`hpbin'
The obsolete binary format used by HPUX's cpio (which stores
device files differently).
`hpodc'
The portable format used by HPUX's cpio (which stores device
files differently).
--quiet
Do not print the number of blocks copied
-R, --owner=[USER][:.][GROUP]
Set the ownership of all files created to the specified USER
and/or GROUP. Either the user, the group, or both, must be
present. If the group is omitted but the ":" or "." separator
is given, use the given user's login group. Only the super-user
can change files' ownership in copy-in mode.
-v, --verbose
List the files processed, or with `-t', give an `ls -l' style
table of contents listing. In a verbose table of contents of a
ustar archive, user and group names in the archive that do not
exist on the local system are replaced by the names that corre-
spond locally to the numeric UID and GID stored in the archive.
-V, --dot
Print a "." for each file processed
-W, --warning=FLAG
Control warning display. Currently FLAG is one of 'none', 'trun-
cate', 'all'. Multiple options accumulate.
Operation modifiers valid in copy-in and copy-out modes:
-F, --file=[[USER@]HOST:]FILE-NAME
Use this FILE-NAME instead of standard input or output. Optional
USER and HOST specify the user and host names in case of a
remote archive
-M, --message=STRING
Print STRING when the end of a volume of the backup media (such
as a tape or a floppy disk) is reached, to prompt the user to
insert a new volume. If STRING contains the string "%d", it is
replaced by the current volume number (starting at 1).
--rsh-command=COMMAND
Use COMMAND instead of rsh (typically /usr/bin/ssh)
Operation modifiers valid only in copy-in mode:
-b, --swap
Swap both halfwords of words and bytes of halfwords in the data.
Equivalent to -sS Use this option to convert 32-bit integers
between big-endian and little-endian machines.
-f, --nonmatching
Only copy files that do not match any of the given patterns
-I [[USER@]HOST:]FILE-NAME
Archive filename to use instead of standard input. Optional
USER and HOST specify the user and host names in case of a
remote archive
-n, --numeric-uid-gid
In the verbose table of contents listing, show numeric UID and
GID
-r, --rename
Interactively rename files
-s, --swap-bytes
Swap the bytes of each halfword in the files
-S, --swap-halfwords
Swap the halfwords of each word (4 bytes) in the files
--to-stdout
Extract files to standard output
-E, --pattern-file=FILE
Read additional patterns specifying filenames to extract or list
from FILE
--only-verify-crc
When reading a CRC format archive, only verify the checksum of
each file in the archive, don't actually extract the files
Operation modifiers valid only in copy-out mode:
-A, --append
Append to an existing archive. The archive must be a disk file
specified with the -O or -F (-file) option.
--device-independent, --reproducible
Create device-independent (reproducible) archives
--ignore-devno
Don't store device numbers
-O [[USER@]HOST:]FILE-NAME
Archive filename to use instead of standard output. Optional
USER and HOST specify the user and host names in case of a
remote archive
--renumber-inodes
Renumber inodes
Operation modifiers valid only in copy-pass mode:
-l, --link
Link files instead of copying them, when possible
Operation modifiers valid in copy-in and copy-out modes:
--absolute-filenames
Do not strip file system prefix components from the file names
--no-absolute-filenames
Create all files relative to the current directory
Operation modifiers valid in copy-out and copy-pass modes:
-0, --null
Filenames in the list are delimited by null characters instead
of newlines, so that files whose names contain newlines can be
archived. GNU find is one way to produce a list of null-termi-
nated filenames.
-a, --reset-access-time
Reset the access times of files after reading them, so that it
does not look like they have just been read.
-L, --dereference
Dereference symbolic links (copy the files that they point
to instead of copying the links).
Operation modifiers valid in copy-in and copy-pass modes:
-d, --make-directories
Create leading directories where needed
-m, --preserve-modification-time
Retain previous file modification times when creating files
--no-preserve-owner
Do not change the ownership of the files; leave them owned by
the user extracting them. This is the default for non-root
users, so that users on System V don't inadvertently give away
files. This option can be used in copy-in mode and copy-pass
mode
--sparse
Write files with large blocks of zeros as sparse files
-u, --unconditional
Replace all files unconditionally
-?, --help
give this help list
--usage
give a short usage message
--version
print program version
Mandatory or optional arguments to long options are also mandatory or
optional for any corresponding short options.
EXAMPLES
When creating an archive, cpio takes the list of files to be processed
from the standard input, and then sends the archive to the standard
output, or to the device defined by the `-F' option. Usually find or
ls is used to provide this list to the standard input. In the follow-
ing example you can see the possibilities for archiving the contents of
a single directory.
% ls | cpio -ov > directory.cpio
The `-o' option creates the archive, and the `-v' option prints the
names of the files archived as they are added. Notice that the options
can be put together after a single `-' or can be placed separately on
the command line. The `>' redirects the cpio output to the file
`directory.cpio'.
If you wanted to archive an entire directory tree, the find command can
provide the file list to cpio:
% find . -print -depth | cpio -ov > tree.cpio
This will take all the files in the current directory, the directories
below and place them in the archive tree.cpio. Again the `-o' creates
an archive, and the `-v' option shows you the name of the files as they
are archived. see "Copy-out mode". Using the `.' in the find state-
ment will give you more flexibility when doing restores, as it will
save file names with a relative path vice a hard wired, absolute path.
The `-depth' option forces `find' to print of the entries in a direc-
tory before printing the directory itself. This limits the effects of
restrictive directory permissions by printing the directory entries in
a directory before the directory name itself.
Extracting an archive requires a bit more thought because cpio will not
create directories by default. Another characteristic, is it will not
overwrite existing files unless you tell it to.
% cpio -iv < directory.cpio
This will retrieve the files archived in the file directory.cpio and
place them in the present directory. The `-i' option extracts the ar-
chive and the `-v' shows the file names as they are extracted. If you
are dealing with an archived directory tree, you need to use the `-d'
option to create directories as necessary, something like:
% cpio -idv < tree.cpio
This will take the contents of the archive tree.cpio and extract it to
the current directory. If you try to extract the files on top of files
of the same name that already exist (and have the same or later modifi-
cation time) cpio will not extract the file unless told to do so by the
-u option. see "Copy-in mode".
In copy-pass mode, cpio copies files from one directory tree to
another, combining the copy-out and copy-in steps without actually
using an archive. It reads the list of files to copy from the standard
input; the directory into which it will copy them is given as a non-
option argument. see "Copy-pass mode".
% find . -depth -print0 | cpio --null -pvd new-dir
The example shows copying the files of the present directory, and sub-
directories to a new directory called new-dir. Some new options are
the `-print0' available with GNU find, combined with the `--null'
option of cpio. These two options act together to send file names
between find and cpio, even if special characters are embedded in the
file names. Another is `-p', which tells cpio to pass the files it
finds to the directory `new-dir'.
AUTHOR
Written by Phil Nelson, David MacKenzie, John Oleynick, and Sergey
Poznyakoff.
REPORTING BUGS
Report bugs to <bug-cpio AT gnu.org>. Report bugs in this manual page via
https://bugzilla.redhat.com.
COPYRIGHT
Copyright (C) 2015 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
The full documentation for cpio is maintained as a Texinfo manual. If
the info and cpio programs are properly installed at your site, the
command
info cpio
should give you access to the complete manual.
The online copy of the documentation is available at the following
address:
http://www.gnu.org/software/cpio/manual
CPIO(1L)