CPIO
Section: Misc. Reference Manual Pages (1L)
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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 storing 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
archive 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 message] [-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
archive 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] [--format=format] [--owner=[user][:.][group]]
[--no-preserve-owner] [--message=message]
[--force-local] [--no-absolute-filenames] [--absolute-filenames]
[--sparse] [--only-verify-crc] [--to-stdout] [--quiet]
[--ignore-devno] [--renumber-inodes] [--device-independent]
[--reproducible]
[--rsh-command=command] [--license] [--usage] [--help]
[--version] [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-preserve-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 indicate 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
having 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
correspond 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', 'truncate', '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-terminated
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 following 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 statement 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 directory 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
archive 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
modification 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@gnu.org>.
Report bugs in this manual page via
https://bugzilla.redhat.com.
COPYRIGHT
Copyright © 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