cpio(1) General Commands Manual cpio(1)
cpio - Copies files to and from archive storage.
cpio -o[aBcehvV] [-C value] [-M"string"] [-Odevice]
cpio -i[bBcdefmrsStuvz6] [-C value] [-M"string"] [-Idevice] [pattern...]
cpio -p[adlmruvV] directory
Interfaces documented on this reference page conform to industry standards as follows:
Refer to the standards(5) reference page for more information about industry standards and associated tags.
A hyphen (-) is required before the -i, -I, -o, -O, and -p options; all other options follow -i, -o, or -p without leading spaces and with-
out a hyphen.
[Tru64 UNIX] The following two options are preceded by a hyphen and must be used separately from the other options. [Tru64 UNIX] Speci-
fies the input device containing the archive. This argument must be present to import data from a device. [Tru64 UNIX] Specifies the
output device to store the archive. This argument must be present to export data to a device.
Not all of the following options can be used with each of the -o, -i, and -p options. Resets the access times of copied files to the cur-
rent time. (When the l option is also specified, the access times of the linked files are not reset.) [Tru64 UNIX] Swaps both bytes and
halfwords. (See also the s and S options.) If there is an odd number of bytes or halfwords in the file being processed, data can be lost.
This option can only be used with cpio -i. Performs block input/output, 5120 bytes to a record. This option cannot be used with cpio -p.
It is meaningful only with data directed to or from /dev/rmt/*. This option does not work with certain magnetic tape drives. The C and B
options are mutually exclusive. If you specify both, the last one on the command line is used. Writes header information in ASCII charac-
ter form. Specify this option when POSIX compliance is required and when you are creating or restoring archives for or from another system.
[Tru64 UNIX] Performs block input/output using value as the record size. The C and B options are mutually exclusive. If you specify
both, the last one on the command line is used. Creates directories as needed. [Tru64 UNIX] Read or write cpio header information in
extended cpio header format. Use this option to read or write block special or character special files. Any cpio archives created with
the e option of Tru64 UNIX Version 4.0 are not backward compatible with earlier versions of Tru64 UNIX. Copies all files except those
matching pattern (cpio -i only). [Tru64 UNIX] Forces cpio to follow symbolic links as if they were normal files or directories. The cpio
command does not follow symbolic links, but instead saves the link text in the archive. Links files rather than copying them, whenever
possible. Hard links are created rather than symbolic (soft) links. This option can be used only with cpio -p. Retains the previous file
modification time. This option cannot be used when copying directories. [Tru64 UNIX] Specifies the End-of-Media message. This option is
used to customize the message that appears when it is time to change archive volumes. The -M option is valid only when -I or -O is also
specified. Causes cpio to ask whether or not to rename each file before copying it. If you do not want to change the file name, enter the
current file name. You can press <Return> only to have cpio skip copying the file. [Tru64 UNIX] Swaps bytes. This option can be used
only with cpio -i. If there is an odd number of bytes in the file being processed, data can be lost. [Tru64 UNIX] Swaps halfwords. This
option can be used only with cpio -i. If there is an odd number of halfwords in the file being processed, data can be lost. Creates a ta-
ble of contents of the input. This option does not copy any files. Copies unconditionally. Otherwise, a file from the archive with the
same name as an existing file in the file system is copied only if the archived file is the newer one. Lists file names. If you use this
option with the t option, the output looks similar to that of the ls -l command. [Tru64 UNIX] Prevents any extended attributes from being
archived with associated files. This option is particularly useful for archiving files that are to be restored with previous versions of
tar and cpio. [Tru64 UNIX] Positions the tape after the EOF marker on extraction or listing. The z option lets the user extract or list
tapes that have multiple archives on them one after the other without error as a result of the tape not being positioned correctly for the
next extraction or listing. [Tru64 UNIX] Processes an old file (one written in UNIX Sixth Edition format). This option can be used only
with cpio -i.
A pathname of an existing directory to be used as the target of cpio -p. Expressions making use of a pattern-matching notation similar to
that used by the shell for file name pattern matching, and similar to regular expressions. The following metacharacters are defined:
Matches any string, including the empty string. Matches any single character. Matches any one of the enclosed characters. A pair of char-
acters separated by `-' matches any symbol between the pair (inclusive), as defined by the system default collating sequence.
In pattern, the special characters ?, *, and [ also match the / character.
Multiple cases of pattern can be specified and if no pattern is specified, the default for pattern is * (that is, select all files).
The cpio command copies files between archive storage and the file system. It is used to save and restore data from traditional format
There are three versions of the cpio command:
cpio -o (copy out)
This command reads file pathnames from standard input and copies these files to standard output along with pathnames and status informa-
tion. Output is padded to a 512-byte boundary.
cpio -i (copy in)
This command reads from standard input an archive file created by the cpio -o command and copies from it the files with names that match
pattern. These files are copied into the current directory tree. The file permissions are the same as the permissions associated with the
files copied out using cpio -o but if umask is used it sets the permissions as per umask. The owner and group of the files are those of the
current user unless the user is superuser, in which case cpio retains the owner and group of the files of the previous cpio -o.
You can list more than one pattern using the file name notation described. The default pattern is *, selecting all files in the archive.
In an expression such as [a-z], the hyphen means "through" according to the current collating sequence. The collating sequence is deter-
mined by the LC_COLLATE environment variable.
cpio -p (directory copy)
This command reads file pathnames from standard input and copies these files into the named directory. The specified directory must
already exist. If these pathnames include directory names and if these directories do not already exist, you must use the -d option to
cause the directories to be created.
[Tru64 UNIX] Special files are not supported. Pathnames cannot exceed 128 bytes. Avoid giving cpio pathnames made up of many uniquely
linked files because cpio might not have enough memory to keep track of them and could lose linking information.
The cpio command is marked as LEGACY in XCU Issue 5.
[Tru64 UNIX] Archives created with extended attributes cannot be read by Version 2.0 of the cpio command. The following describes the
results of restoring archived files and directories when you use Version 2.0 of the cpio command: [Tru64 UNIX] You cannot restore an ar-
chive directory with extended attributes. The extended attributes are restored as a regular file that cannot be overwritten; the original
directory cannot be recreated. In addition, the cpio command restores the archived files containing extended attributes as regular files.
When the cpio command restores the original file with the extended attributes, the command fails with errno:20. [Tru64 UNIX] You cannot
archive files with extended attributes. [Tru64 UNIX] Archives created with the new pax utility and having cpio format, can be restored
using only the new pax or cpio commands even if none of the archived files have extended attributes.
To achieve backward compatibility of archived files, use the following suggestions: Archive only files that do not have extended
attributes. Use the old cpio command at /usr/opt/obsolete/usr/bin/cpio.
[Tru64 UNIX] When redirecting the output from cpio to a special file (device), redirect it to the raw device and not the block device.
Because writing to a block device is done asynchronously, there is no way to know if the end of the device has been reached.
The following exit values are returned: Successful completion. An error occurred.
To copy files to magnetic tape, enter: cpio -ov < file-list -O/dev/rmt12
This command copies the files with pathnames that are listed in the file specification in a compact form to the magnetic tape
(/dev/rmt12). The -v option causes cpio to display the name of each file as it is copied. This command is useful for making backup
copies of files. To copy files in the current directory whose names end with onto magnetic tape, enter: ls *.c | cpio -ov
To copy the current directory and all subdirectories onto magnetic tape, enter: find . -print | cpio -ov -O/dev/rmt12
This command saves the directory tree that starts with the current directory (.) and includes all of its subdirectories and files.
Another way to do the same thing is by entering the following command: find . -cpio /dev/rmt12 -print
The -print option displays the name of each file as it is copied. To list the files that have been saved onto a magnetic tape with
cpio, enter: cpio -itv -I/dev/rmt12
This command displays the table of contents of the data previously saved onto /dev/rmt12 in cpio format. To list only the file
pathnames, use only the -it options. To copy the files previously saved with cpio from a magnetic tape, enter: cpio -idmv
This command copies the files previously saved onto /dev/rmt12 by cpio back into the file system (specified by the -i option). The
-d option lets cpio create the appropriate directories if a directory tree was saved. The -m option maintains the last modification
time that was in effect when the files were saved. The -v option causes cpio to display the name of each file as it is copied. To
copy selected files from magnetic tape, enter: cpio -i -I/dev/rmt12 "*.c" "*.o"
This command copies the files that end with or from magnetic tape. The patterns *.c and *.o must be enclosed in double quotation
marks (" ") to prevent the shell from treating the * (asterisk) as a pattern-matching character. In this special case, cpio itself
decodes the pattern-matching characters. To rename files as they are copied from magnetic tape, enter: cpio -ir -I/dev/rmt12
The -r option causes cpio to ask you whether or not to rename each file before copying it from magnetic tape. For example, the fol-
lowing message asks you whether you want to give the file saved as prog.c a new name as it is being copied: Rename <prog.c>
To rename the file, type the new name and press <Return>. To keep the same name, you must enter the old name at the prompt. To
avoid copying the file at all, press <Return> alone. To copy a directory and all of its subdirectories, enter: mkdir /u/jim/newdir
find . -print | cpio -pdl /u/jim/newdir
This command duplicates the current directory tree, including the current directory and all of its subdirectories and files. The
duplicate is placed in the new /u/jim/newdir directory. The -l option causes cpio to link files instead of copying them, when pos-
The following environment variables affect the execution of cpio: Provides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from the default locale is used. If any of the internationalization vari-
ables contain an invalid setting, the utility behaves as if none of the variables had been defined. If set to a non-empty string value,
overrides the values of all the other internationalization variables. Determines the locale for the interpretation of sequences of bytes
of text data as characters (for example, single-byte as opposed to multibyte characters in arguments and input files) and the behavior of
character classes within bracketed file name patterns. Determines the locale for the format and contents of diagnostic messages written to
standard error. Determines the format of date and time strings output when listing the contents of an archive with the -v option. Deter-
mines the location of message catalogues for the processing of LC_MESSAGES. Determines the time zone used with date and time strings.
Commands: ar(1), find(1), ls(1), ksh(1), pax(1), Bourne shell sh(1b), POSIX shell sh(1p), tar(1)