3.4 Options

This section summarizes all available command line options. References in square brackets after each option indicate cpio modes in which this option is valid.

-0

--null

[copy-in,copy-out,copy-pass]
Read a list of filenames terminated by a null character, instead of a newline, so that files whose names contain newlines can be archived. GNU find is one way to produce a list of null-terminated filenames. This option may be used in copy-out and copy-pass modes.

-a

--reset-access-time

[copy-out,copy-pass]
Reset the access times of files after reading them, so that it does not look like they have just been read.

-A

--append

[copy-out]
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

[copy-in]
Swap both halfwords of words and bytes of halfwords in the data. Equivalent to ‘-sS’. This option may be used in copy-in mode. Use this option to convert 32-bit integers between big-endian and little-endian machines.

-B

[copy-in,copy-out,copy-pass]
Set the I/O block size to 5120 bytes. Initially the block size is 512 bytes.

--block-size=block-size

[copy-in,copy-out,copy-pass]
Set the I/O block size to block-size * 512 bytes.

-c

[copy-in,copy-out,copy-pass]
Use the old portable (ASCII) archive format.

-C io-size

--io-size=io-size

[copy-in,copy-out,copy-pass]
Set the I/O block size to io-size bytes.

-d

--make-directories

[copy-in,copy-pass]
Create leading directories where needed.

-D dir

--directory=dir

[copy-in,copy-out,copy-pass]
Change to the directory dir before starting the operation. This can be used, for example, to extract an archive contents in a different directory:

$ cpio -i -D /usr/local < archive

or to copy-pass files from one directory to another:

$ cpio -D /usr/bin -p /usr/local/bin < filelist

The ‘-D’ option does not affect file names supplied as arguments to another command line options, such as ‘-F’ or ‘-E’. For example, the following invocation:

cpio -D /tmp/foo -d -i -F arc

instructs cpio to open the archive file ‘arc’ in the current working directory, then change to the directory ‘/tmp/foo’ and extract files to that directory. If ‘/tmp/foo’ does not exist, it will be created first (the ‘-d’ option) and then changed to.

-E file

--pattern-file=file

[copy-in]
Read additional patterns specifying filenames to extract or list from file. 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

[copy-in]
Only copy files that do not match any of the given patterns.

-F archive

--file=archive

[copy-in,copy-out]
Archive filename to use instead of standard input or output. To use a tape drive on another machine as the archive, use a filename that starts with ‘hostname:’, where hostname is the name or IP address of the machine. 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

[copy-in,copy-out]
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

[copy-in,copy-out,copy-pass]
Use archive format format. The valid formats are listed below with file size limits for individual files in parentheses; 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. (2147483647 bytes)

‘odc’

The old (POSIX.1) portable format. (8589934591 bytes)

‘newc’

The new (SVR4) portable format, which supports file systems having more than 65536 i-nodes. (4294967295 bytes)

‘crc’

The new (SVR4) portable format with a checksum added.

‘tar’

The old tar format. (8589934591 bytes)

‘ustar’

The POSIX.1 tar format. Also recognizes GNU tar archives, which are similar but not identical. (8589934591 bytes)

‘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 section Copy-in mode.

-I archive

[copy-in]
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:’, where hostname is the name or IP address of the remote host. 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).

-l

--link

[copy-pass]
Link files instead of copying them, when possible.

-L

--dereference

[copy-in,copy-pass]
Copy the file that a symbolic link points to, rather than the symbolic link itself.

-m

--preserve-modification-time

[copy-in,copy-pass]
Retain previous file modification times when creating files.

-M message

--message=message

[copy-in,copy-out]
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. If message contains the string ‘%d’, it is replaced by the current volume number (starting at 1).

-n

--numeric-uid-gid

[copy-in]
Show numeric UID and GID instead of translating them into names when using the ‘--verbose’ option.

--no-absolute-filenames

[copy-in,copy-out]
Create all files relative to the current directory in copy-in mode, even if they have an absolute file name in the archive.

--no-preserve-owner

[copy-in,copy-pass]
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 inadvertantly give away files. This option can be used in copy-in mode and copy-pass mode

-o

--create

Run in copy-out mode. See section Copy-out mode.

-O archive

[copy-out]
Archive filename to use instead of standard output. To use a tape drive on another machine as the archive, use a filename that starts with ‘hostname:’, where hostname is the name or IP address of the machine. 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

[copy-in]
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 section Copy-pass mode.

--quiet

[copy-in,copy-out,copy-pass]
Do not print the number of blocks copied.

-r

--rename

[copy-in]
Interactively rename files.

-R owner

--owner owner

[copy-in,copy-out,copy-pass]
In copy-in and copy-pass mode, set the ownership of all files created to the specified owner (this operation is allowed only for the super-user). In copy-out mode, store the supplied owner information in the archive.

The argument can be either the user name or the user name and group name, separated by a dot or a colon, or the group name, preceeded by a dot or a colon, as shown in the examples below:

cpio --owner smith
cpio --owner smith:
cpio --owner smith:users
cpio --owner :users

The argument parts are first looked up in the system user and group databases, correspondingly. If any of them is not found there, it is treated as numeric UID or GID, provided that it consists of decimal digits only.

To avoid the lookup and ensure that arguments are treated as numeric values, prefix them with a plus sign, e.g.:

cpio --owner +0
cpio --owner +0:
cpio --owner +0:+0
cpio --owner :+0

If the group is omitted but the ‘:’ or ‘.’ separator is given, as in the second example. the given user’s login group will be used.

--rsh-command=command

[copy-in,copy-out,copy-pass]
Notifies cpio that is should use command to communicate with remote devices.

-s

--swap-bytes

[copy-in]
Swap the bytes of each halfword (pair of bytes) in the files. This option can be used in copy-in mode.

-S

--swap-halfwords

[copy-in]
Swap the halfwords of each word (4 bytes) in the files. This option may be used in copy-in mode.

--sparse

[copy-in,copy-pass]
Write files with large blocks of zeros as sparse files. This option is used in copy-in and copy-pass modes.

-t

--list

[copy-in]
Print a table of contents of the input. Can be used alone, as a mode designator, in which case ‘-i’ is implied.

--to-stdout

[copy-in]
Extract files to standard output. This option may be used in copy-in mode.

-u

--unconditional

[copy-in,copy-pass]
Replace all files, without asking whether to replace existing newer files with older files.

-v

--verbose

[copy-in,copy-out,copy-pass]
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

[copy-in,copy-out,copy-pass]
Print a ‘.’ for each file processed.

--version

Print the cpio program version number and exit.

-W

--warning=flag

[copy-in,copy-out,copy-pass]
Control warning display. The argument is one of the following:

none

Disable all warnings.

all

Enable all warnings.

truncate

Warn about truncation of file header fields.

no-truncate

Disable truncation warnings.

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