Copy files to and from archives.
The 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.
Syntax
Copy-In mode:
cpio {-i|--extract} [-bcdfmnrtsuvBSV] [-C bytes] [-E file] [-H format] [-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] [--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]
[--rsh-command=command] [--help] [--version] [pattern...] [< archive]
Copy-Out mode:
cpio {-o|--create} [-0acvABLV] [-C bytes] [-H format] [-M message] [-O [[user@]host:]archive]
[-F [[user@]host:]archive] [--file=[[user@]host:]archive] [--format=format] [--message=message]
[--null] [--reset-access-time] [--verbose] [--dot] [--append] [--block-size=blocks]
[--dereference] [--io-size=bytes] [--rsh-command=command] [--help] [--version] < name-list [> archive]
Pass-Thru mode:
cpio {-p|--pass-through} [-0adlmuvLV] [-R [user][:.][group]] [--null] [--reset-access-time]
[--make-directories] [--link] [--quiet] [--preserve-modification-time] [--unconditional] [--verbose]
[--dot] [--dereference] [--owner=[user][:.][group]] [--no-preserve-owner] [--sparse] [--help]
[--version] destination-directory < name-list
The first option to cpio is a mode indicator:
-i Copy-in mode. Read an archive from standard input (unless overriden) and extract the contents to disk
or (if the -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.
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.
-o Copy-out mode. Read a list of filenames, one per line, from standard input and produce a new archive on standard output
(unless overriden) containing the specified items.
-p Pass-Thru mode. Read a list of filenames from standard input and copy the files to the specified directory.
This combines the copy-out and copy-in steps without actually using an archive.
Options:
Unless specifically stated otherwise, options are applicable in all operating modes.
-0, --null
Read filenames separated by NUL characters instead of newlines. (copy-out and pass-thru modes.)
This is necessary if any of the filenames being read might contain newlines.
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.
(copy-out and pass-thru modes.)
-A, --append
Append to an existing archive. (Only works in copy-out mode.)
The archive must be a disk file specified with the -O or -F (-file) option.
-b, --swap
Swap both halfwords of words and bytes of halfwords in the data. Equivalent to -sS.
(may be used in copy-in mode.)
Use this option to convert 32-bit integers between big-endian and little-endian machines.
-B
Set the I/O block size to 5120 bytes. Initially the block size is 512 bytes. (copy-out mode only)
--block-size=BLOCK-SIZE
Set the I/O block size to BLOCK-SIZE * 512 bytes.
-c Identical to '-H newc', use the new (SVR4 ) portable format. (copy-out mode only)
If you wish the old portable (ASCII ) archive format, use '-H odc' instead.
-C IO-SIZE, --io-size=IO-SIZE
Set the I/O block size to IO-SIZE bytes. (copy-out mode only.)
-d, --make-directories
Create leading directories where needed. (copy-in and pass-thru modes.)
-E FILE, --pattern-file=FILE
Read additional patterns specifying filenames to extract or list from FILE. (copy-in mode only.)
The lines of FILE are treated as if they had been non-option arguments to cpio. This option is used in copy-in mode,
-f, --nonmatching
Only copy files that do not match any of the given patterns.
-F, --file=archive
Archive filename to use instead of standard input or output. (copy-in mode only.)
To use a tape drive on another machine as the archive, use a filename that starts with 'HOSTNAME: '.
The hostname can be preceded by a username and an '@' to access the remote tape drive as that user, if you have
permission to do so (typically an entry in that user’s '~/.rhosts' file).
--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=FORMAT
Use archive format 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 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).
-i, --extract
Run in copy-in mode. see 'Copy-in mode'.
-I archive
Archive filename to use instead of standard input.
To use a tape drive on another machine as the archive, use a filename that starts with 'HOSTNAME: '.
The hostname can be preceded by a username and an '@' to access the remote tape drive as that user, if you
have permission to do so (typically an entry in that user’s '~/.rhosts' file).
-k
Ignored; for compatibility with other versions of cpio.
-l, --link
Link files instead of copying them, when possible. (pass-thru mode only.)
-L, --dereference
Copy the file that a symbolic link points to, rather than the symbolic link itself. (copy-out and pass-thru modes.)
-m, --preserve-modification-time
Retain previous file modification times when creating files. (copy-in and pass-thru modes.)
-M MESSAGE, --message=MESSAGE
Print MESSAGE 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. (copy-in and copy-out modes.)
If MESSAGE contains the string '%d', it is replaced by the current volume number (starting at 1).
-n, --numeric-uid-gid
Show numeric UID and GID instead of translating them into names when using the '--verbose option'.
(i mode, only with -t)
--no-absolute-filenames
Create all files relative to the current directory in copy-in mode, even if they have an absolute file name in the archive.
--absolute-filenames' (default)
Do not strip leading file name components that contain '..' and leading slashes from file names in copy-in mode
--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.)
-o, --create
Run in copy-out mode. see 'Copy-out mode'.
-O archive
Archive filename to use instead of standard output. (Copy-out mode only)
To use a tape drive on another machine as the archive, use a filename that starts with 'HOSTNAME: '.
The hostname can be preceded by a username and an '@' to access the remote tape drive as that user, if you
have permission to do so (typically an entry in that user’s '~/.rhosts' file).
--only-verify-crc
Verify the CRC’s of each file in the archive, when reading a CRC format archive.
Don’t actually extract the files.
-p, --pass-through
Run in copy-pass mode. see 'Copy-pass mode'.
--quiet
Do not print the number of blocks copied.
-r, --rename
Interactively rename files.
-R [user][:.][group], --owner [user][:.][group]
Set the ownership of all files created to the specified user and/or group in copy-out and copy-pass modes.
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.
--rsh-command=COMMAND
Notifies cpio that is should use COMMAND to communicate with remote devices.
-s, --swap-bytes
Swap the bytes of each halfword (pair of bytes) in the files. (copy-in mode.)
-S, --swap-halfwords
Swap the halfwords of each word (4 bytes) in the files. (copy-in mode.)
--sparse
Write files with large blocks of zeros as sparse files. (copy-in and copy-pass modes.)
-t, --list
Print a table of contents of the input. (Copy-in mode only.)
--to-stdout
Extract files to standard output. (copy-in mode.)
-u, --unconditional
Replace all files, without asking whether to replace existing newer files with older files.
(copy-in and copy-pass modes.)
-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.
--version
Print the cpio program version number and exit.
EXIT STATUS
The cpio utility exits 0 on success, and >0 if an error occurs.
The cpio command is traditionally used to copy file hierarchies in conjunction with the find command. When creating an archive in copy-out mode give find the -depth option to minimize problems with permissions on directories that are unreadable.
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.
Archive the content of a single directory, -ov = Copy-out + view all files:
ls | cpio -ov > directory.cpio
Copy all files from src to dest, the find command can provide the file list to cpio,
-pmud = Set file modification time + Unconditionally overwrite + Create directories as necessary:
find src | cpio -pmud dest
Archive an entire directory tree:
find . -print -depth | cpio -ov > tree.cpio
Take the contents of the archive tree.cpio and extract it to the current directory
-idv = Copy-In + Create directories + verbose
cpio -idv < tree.cpio
Copy files from src to dest that are more than 2 days old and which contain the word 'foobar':
find src -mtime +2 | xargs grep -l foobar | cpio -pdmu dest
By carefully selecting options to the find 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 src to dest that are more than 2 days old and whose names match a particular pattern:
find src -mtime +2 | grep foo[bar] | cpio -pdmu dest
“R2D2! You know better than to trust a strange computer!” ~ C3PO (The Empire Strikes Back)
info cpio
https://www.gnu.org/software/cpio/manual
cp - Copy one or more files to another location.
dd - Data Duplicator - convert and copy a file (use for RAW storage)
install - Copy files and set attributes.
mv - Move or rename files or directories.
rcp - Remote copy.