CPIO(1) 		  BSD General Commands Manual		       CPIO(1)

NAME

     cpio — copy files to and from archives

SYNOPSIS

     cpio -i [options] [pattern ...] [< archive]

     cpio -o [options] < name-list [> archive]

     cpio -p [options] dest-dir < name-list

DESCRIPTION

     cpio copies files between archives and directories.  This implementation

     can extract from tar, pax, cpio, zip, jar, ar, and ISO 9660 cdrom images

     and can create tar, pax, cpio, ar, and shar archives.

     The first option to cpio is a mode indicator from the following list:

     -i      Input.  Read an archive from standard input (unless overridden)

	     and extract the contents to disk or (if the -t option is speci‐

	     fied) list the contents to standard output.  If one or more file

	     patterns are specified, only files matching one of the patterns

	     will be extracted.

     -o      Output.  Read a list of filenames from standard input and produce

	     a new archive on standard output (unless overridden) containing

	     the specified items.

     -p      Pass-through.  Read a list of filenames from standard input and

	     copy the files to the specified directory.

OPTIONS

     Unless specifically stated otherwise, options are applicable in all oper‐

     ating modes.

     -0, --null

	     Read filenames separated by NUL characters instead of newlines.

	     This is necessary if any of the filenames being read might con‐

	     tain newlines.

     -A      (o mode only) Append to the specified archive.  (Not yet imple‐

	     mented.)

     -a      (o and p modes) Reset access times on files after they are read.

     -B      (o mode only) Block output to records of 5120 bytes.

     -C size

	     (o mode only) Block output to records of size bytes.

     -c      (o mode only) Use the old POSIX portable character format.

	     Equivalent to --format odc.

     -d, --make-directories

	     (i and p modes) Create directories as necessary.

     -E file

	     (i mode only) Read list of file name patterns from file to list

	     and extract.

     -F file, --file file

	     Read archive from or write archive to file.

     -f pattern

	     (i mode only) Ignore files that match pattern.

     -H format, --format format

	     (o mode only) Produce the output archive in the specified format.

	     Supported formats include:

	     cpio     Synonym for odc.

	     newc     The SVR4 portable cpio format.

	     odc      The old POSIX.1 portable octet-oriented cpio format.

	     pax      The POSIX.1 pax format, an extension of the ustar for‐

		      mat.

	     ustar    The POSIX.1 tar format.

	     The default format is odc.  See libarchive-formats(5) for more

	     complete information about the formats currently supported by the

	     underlying libarchive(3) library.

     -h, --help

	     Print usage information.

     -I file

	     Read archive from file.

     -i, --extract

	     Input mode.  See above for description.

     --insecure

	     (i and p mode only) Disable security checks during extraction or

	     copying.  This allows extraction via symbolic links, absolute

	     paths, and path names containing ‘..’ in the name.

     -J, --xz

	     (o mode only) Compress the file with xz-compatible compression

	     before writing it.  In input mode, this option is ignored; xz

	     compression is recognized automatically on input.

     -j      Synonym for -y.

     -L      (o and p modes) All symbolic links will be followed.  Normally,

	     symbolic links are archived and copied as symbolic links.	With

	     this option, the target of the link will be archived or copied

	     instead.

     -l, --link

	     (p mode only) Create links from the target directory to the orig‐

	     inal files, instead of copying.

     --lrzip

	     (o mode only) Compress the resulting archive with lrzip(1).  In

	     input mode, this option is ignored.

     --lz4   (o mode only) Compress the archive with lz4-compatible compres‐

	     sion before writing it.  In input mode, this option is ignored;

	     lz4 compression is recognized automatically on input.

     --zstd  (o mode only) Compress the archive with zstd-compatible compres‐

	     sion before writing it.  In input mode, this option is ignored;

	     zstd compression is recognized automatically on input.

     --lzma  (o mode only) Compress the file with lzma-compatible compression

	     before writing it.  In input mode, this option is ignored; lzma

	     compression is recognized automatically on input.

     --lzop  (o mode only) Compress the resulting archive with lzop(1).  In

	     input mode, this option is ignored.

     --passphrase passphrase

	     The passphrase is used to extract or create an encrypted archive.

	     Currently, zip is only a format that cpio can handle encrypted

	     archives.	You shouldn't use this option unless you realize how

	     insecure use of this option is.

     -m, --preserve-modification-time

	     (i and p modes) Set file modification time on created files to

	     match those in the source.

     -n, --numeric-uid-gid

	     (i mode, only with -t) Display numeric uid and gid.  By default,

	     cpio displays the user and group names when they are provided in

	     the archive, or looks up the user and group names in the system

	     password database.

     --no-preserve-owner

	     (i mode only) Do not attempt to restore file ownership.  This is

	     the default when run by non-root users.

     -O file

	     Write archive to file.

     -o, --create

	     Output mode.  See above for description.

     -p, --pass-through

	     Pass-through mode.  See above for description.

     --preserve-owner

	     (i mode only) Restore file ownership.  This is the default when

	     run by the root user.

     --quiet

	     Suppress unnecessary messages.

     -R [user][:][group], --owner [user][:][group]

	     Set the owner and/or group on files in the output.  If group is

	     specified with no user (for example, -R :wheel) then the group

	     will be set but not the user.  If the user is specified with a

	     trailing colon and no group (for example, -R root:) then the

	     group will be set to the user's default group.  If the user is

	     specified with no trailing colon, then the user will be set but

	     not the group.  In -i and -p modes, this option can only be used

	     by the super-user.  (For compatibility, a period can be used in

	     place of the colon.)

     -r      (All modes.)  Rename files interactively.	For each file, a

	     prompt is written to /dev/tty containing the name of the file and

	     a line is read from /dev/tty.  If the line read is blank, the

	     file is skipped.  If the line contains a single period, the file

	     is processed normally.  Otherwise, the line is taken to be the

	     new name of the file.

     -t, --list

	     (i mode only) List the contents of the archive to stdout; do not

	     restore the contents to disk.

     -u, --unconditional

	     (i and p modes) Unconditionally overwrite existing files.	Ordi‐

	     narily, an older file will not overwrite a newer file on disk.

     -V, --dot

	     Print a dot to stderr for each file as it is processed.  Super‐

	     seded by -v.

     -v, --verbose

	     Print the name of each file to stderr as it is processed.	With

	     -t, provide a detailed listing of each file.

     --version

	     Print the program version information and exit.

     -y      (o mode only) Compress the archive with bzip2-compatible compres‐

	     sion before writing it.  In input mode, this option is ignored;

	     bzip2 compression is recognized automatically on input.

     -Z      (o mode only) Compress the archive with compress-compatible com‐

	     pression before writing it.  In input mode, this option is

	     ignored; compression is recognized automatically on input.

     -z      (o mode only) Compress the archive with gzip-compatible compres‐

	     sion before writing it.  In input mode, this option is ignored;

	     gzip compression is recognized automatically on input.

EXIT STATUS

     The cpio utility exits 0 on success, and >0 if an error occurs.

ENVIRONMENT

     The following environment variables affect the execution of cpio:

     LANG	The locale to use.  See environ(7) for more information.

     TZ 	The timezone to use when displaying dates.  See environ(7) for

		more information.

EXAMPLES

     The cpio command is traditionally used to copy file hierarchies in con‐

     junction with the find(1) command.  The first example here simply copies

     all files from src to dest:

	   find src | cpio -pmud dest

     By carefully selecting options to the find(1) command and combining it

     with other standard utilities, it is possible to exercise very fine con‐

     trol 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 partic‐

     ular pattern:

	   find src -mtime +2 | grep foo[bar] | cpio -pdmu dest

     This example copies 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

COMPATIBILITY

     The mode options i, o, and p and the options a, B, c, d, f, l, m, r, t,

     u, and v comply with SUSv2.

     The old POSIX.1 standard specified that only -i, -o, and -p were inter‐

     preted as command-line options.  Each took a single argument of a list of

     modifier characters.  For example, the standard syntax allows -imu but

     does not support -miu or -i -m -u, since m and u are only modifiers to

     -i, they are not command-line options in their own right.	The syntax

     supported by this implementation is backwards-compatible with the stan‐

     dard.  For best compatibility, scripts should limit themselves to the

     standard syntax.

SEE ALSO

     bzip2(1), tar(1), gzip(1), mt(1), pax(1), libarchive(3), cpio(5),

     libarchive-formats(5), tar(5)

STANDARDS

     There is no current POSIX standard for the cpio command; it appeared in

     ISO/IEC 9945-1:1996 (“POSIX.1”) but was dropped from IEEE Std 1003.1-2001

     (“POSIX.1”).

     The cpio, ustar, and pax interchange file formats are defined by IEEE Std

     1003.1-2001 (“POSIX.1”) for the pax command.

HISTORY

     The original cpio and find utilities were written by Dick Haight while

     working in AT&T's Unix Support Group.  They first appeared in 1977 in

     PWB/UNIX 1.0, the “Programmer's Work Bench” system developed for use

     within AT&T.  They were first released outside of AT&T as part of System

     III Unix in 1981.	As a result, cpio actually predates tar, even though

     it was not well-known outside of AT&T until some time later.

     This is a complete re-implementation based on the libarchive(3) library.

BUGS

     The cpio archive format has several basic limitations: It does not store

     user and group names, only numbers.  As a result, it cannot be reliably

     used to transfer files between systems with dissimilar user and group

     numbering.  Older cpio formats limit the user and group numbers to 16 or

     18 bits, which is insufficient for modern systems.  The cpio archive for‐

     mats cannot support files over 4 gigabytes, except for the “odc” variant,

     which can support files up to 8 gigabytes.

BSD			      September 16, 2014			   BSD