[ << ] [ < ] [ Up ] [ > ] [ >> ]         [Top] [Contents] [Index] [ ? ]

3 Invoking cpio


[ << ] [ < ] [ Up ] [ > ] [ >> ]         [Top] [Contents] [Index] [ ? ]

3.1 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.

Copy-out mode is requested by the ‘-o’ (‘--create’) command line option, e.g.:

% find | cpio -o > directory.cpio

The following options can be used in copy-out mode:

-0
--null

Filenames in the list are delimited by ASCII null characters instead of newlines.

-A
--append

Append to an existing archive.

-a
--reset-access-time

Reset the access times of files after reading them.

--absolute-filenames

Do not strip file system prefix components from the file names. This is the default.

--no-absolute-filenames

Strip file system prefix components from the file names before storing them to the archive.

--block-size=block-size

Sets the I/O block size to block-size * 512 bytes.

-B

Set the I/O block size to 5120 bytes.

-c

Use the old portable (ASCII) archive format.

-C number
--io-size=number

Set the I/O block size to the given number of bytes.

-D dir
--directory=dir

Change to directory dir

--force-local

Treat the archive file as local, even if its name contains colons.

-F [[user@]host:]archive-file
-O [[user@]host:]archive-file
--file=[[user@]host:]archive-file

Use the supplied archive-file instead of standard input. Optional user and host specify the user and host names in case of a remote archive.

-H format
--format=format

Use given archive format. See format, for a list of available formats.

-L
--dereference

Dereference symbolic links (copy the files that they point to instead of copying the links).

-M string
--message=string

Print string when the end of a volume of the backup media is reached.

--quiet

Do not print the number of blocks copied.

--rsh-command=command

Use command instead of rsh to access remote archives.

-R
--owner=[user][:.][group]

Set the ownership of all files created to the specified user and/or group. See owner.

-v
--verbose

Verbosely list the files processed.

-V
--dot

Print a ‘.’ for each file processed.

-W
--warning=flag

Control warning display. Argument is one of ‘none’, ‘truncate’, ‘no-truncate’ or ‘all’. See warning, for a detailed discussion of these.


[ << ] [ < ] [ Up ] [ > ] [ >> ]         [Top] [Contents] [Index] [ ? ]

3.2 Copy-in mode

In copy-in mode, cpio copies files from an archive into the filesystem 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.

The copy-in mode is requested by the ‘-i’ (‘--extract’) command line option.

The following options can be used in copy-in mode:

--absolute-filenames

Do not strip file system prefix components from the file names. This is the default.

--no-absolute-filenames

Create all files relative to the current directory.

--block-size=block-size

Sets the I/O block size to block-size * 512 bytes.

-b
--swap

Swap both halfwords of words and bytes of halfwords in the data. Equivalent to ‘-sS’.

-B

Set the I/O block size to 5120 bytes.

-c

Use the old portable (ASCII) archive format.

-C number
--io-size=number

Set the I/O block size to the given number of bytes.

-D dir
--directory=dir

Change to directory dir

-d
--make-directories

Create leading directories where needed.

-E file
--pattern-file=file

Read additional patterns specifying filenames to extract or list from file.

-f
--nonmatching

Only copy files that do not match any of the given patterns.

--force-local

Treat the archive file as local, even if its name contains colons.

-F [[user@]host:]archive-file
-I [[user@]host:]archive-file
--file=[[user@]host:]archive-file

Use the supplied archive-file instead of standard input. Optional user and host specify the user and host names in case of a remote archive.

-H format
--format=format

Use given archive format. See format, for a list of available formats.

-m
--preserve-modification-time

Retain previous file modification times when creating files.

-M string
--message=string

Print string when the end of a volume of the backup media is reached.

--no-preserve-owner

Do not change the ownership of the files.

-n
--numeric-uid-gid

In the verbose table of contents listing, show numeric UID and GID values.

--only-verify-crc

When reading a CRC format archive, only verify the CRC’s of each file in the archive, don’t actually extract the files

--quiet

Do not print the number of blocks copied.

--rsh-command=command

Use command instead of rsh to access remote archives.

-r
--rename

Interactively rename files

--sparse

Write files with large blocks of zeros as sparse 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.

-u
--unconditional

Replace all files unconditionally.

-v
--verbose

Verbosely list the files processed.

-V
--dot

Print a ‘.’ for each file processed.

-W
--warning=flag

Control warning display. Argument is one of ‘none’, ‘truncate’, ‘no-truncate’ or ‘all’. See warning, for a detailed discussion of these.


[ << ] [ < ] [ Up ] [ > ] [ >> ]         [Top] [Contents] [Index] [ ? ]

3.3 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.

This mode is requested by the ‘-p’ (‘--pass-through’) command line option.

The following options are valid in copy-out mode:

-0
--null

Filenames in the list are delimited by ASCII null characters instead of newlines.

-a
--reset-access-time

Reset the access times of files after reading them.

-b
--swap

Swap both halfwords of words and bytes of halfwords in the data. Equivalent to ‘-sS’.

--block-size=block-size

Sets the I/O block size to block-size * 512 bytes.

-B

Set the I/O block size to 5120 bytes.

-c

Use the old portable (ASCII) archive format.

-C number
--io-size=number

Set the I/O block size to the given number of bytes.

-d
--make-directories

Create leading directories where needed.

--device-independent
--reproducible

Create reproducible archives. This is equivalent to ‘--ignore-devno --renumber-inodes’.

-D dir
--directory=dir

Change to directory dir

-E file
--pattern-file=file

Read additional patterns specifying filenames to extract or list from file.

-f
--nonmatching

Only copy files that do not match any of the given patterns.

-F [[user@]host:]archive-file
-O [[user@]host:]archive-file
--file=[[user@]host:]archive-file

Use the supplied archive-file instead of standard input. Optional user and host specify the user and host names in case of a remote archive.

--force-local

Treat the archive file as local, even if its name contains colons.

-H format
--format=format

Use given archive format. See format, for a list of available formats.

--ignore-devno

Store 0 in the device number field of each archive member, instead of the actual device number.

-l
--link

Link files instead of copying them, when possible.

-L
--dereference

Dereference symbolic links (copy the files that they point to instead of copying the links).

-m
--preserve-modification-time

Retain previous file modification times when creating files.

-M string
--message=string

Print string when the end of a volume of the backup media is reached.

-n
--numeric-uid-gid

In the verbose table of contents listing, show numeric UID and GID values.

--no-preserve-owner

Do not change the ownership of the files.

--only-verify-crc

When reading a CRC format archive, only verify the CRC’s of each file in the archive, don’t actually extract the files

--quiet

Do not print the number of blocks copied.

--rsh-command=command

Use command instead of rsh to access remote archives.

-r
--rename

Interactively rename files

--renumber-inodes

Renumber inodes when storing them in the archive.

-R
--owner=[user][:.][group]

Set the ownership of all files created to the specified user and/or group. See owner.

-s
--swap-bytes

Swap the bytes of each halfword in the files

--sparse

Write files with large blocks of zeros as sparse files.

-S
--swap-halfwords

Swap the halfwords of each word (4 bytes) in the files

--to-stdout

Extract files to standard output.

-u
--unconditional

Replace all files unconditionally.

-v
--verbose

Verbosely list the files processed.

-V
--dot

Print a ‘.’ for each file processed.

-W
--warning=flag

Control warning display. Argument is one of ‘none’, ‘truncate’, ‘no-truncate’ or ‘all’. See warning, for a detailed discussion of these.


[ << ] [ < ] [ Up ] [ > ] [ >> ]         [Top] [Contents] [Index] [ ? ]

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.


[ << ] [ >> ]           [Top] [Contents] [Index] [ ? ]

This document was generated on March 24, 2021 using texi2html 5.0.