CPIO

Section: User Commands (1)
Updated: USENIX Association
Index Return to Main Contents
 

NAME

cpio - copy file archives in and out  

SYNOPSIS

cpio -o[Bacv]
cpio -i[Bcdfmrtuv] [pattern...]
cpio -p[adlmruv] directory  

DESCRIPTION

The cpio utility produces and reads files in the format specified by the cpio Archive/Interchange File Format specified in IEEE Std. 1003.1-1988.

The cpio -i (copy in) utility extracts files from the standard input, which is assumed to be the product of a previous cpio -o . Only files with names that match patterns are selected. Multiple patterns may be specified and if no patterns are specified, the default for patterns is selecting all files. The extracted files are conditionally created and copied into the current directory, and possibly any levels below, based upon the options described below and the permissions of the files will be those of the previous cpio -o . The owner and group of the files will be that of the current user unless the user has appropriate privileges, which causes cpio to retains the owner and group of the files of the previous cpio -o .

The cpio -p (pass) utility reads the standard input to obtain a list of path names of files that are conditionally created and copied into the destination directory based upon the options described below.

If an error is detected, the cause is reported and the cpio utility will continue to copy other files. cpio will skip over any unrecognized files which it encounters in the archive.

The following restrictions apply to the cpio utility:

1
Pathnames are restricted to 256 characters.
2
Appropriate privileges are required to copy special files.
3
Blocks are reported in 512-byte quantities.
 

Options

The following options are available:
-B
Input/output is to be blocked 5120 bytes to the record. Can only be used with cpio -o or cpio -i for data that is directed to or from character special files.
-a
Reset access times of input files after they have been copied. When the -l option is also specified, the linked files do not have their access times reset. Can only be used with cpio -o or cpio -i .
-c
Write header information in ASCII character for for portability. Can only be used with cpio -i or cpio -o . Note that this option should always be used to write portable files.
-d
Creates directories as needed. Can only be used with cpio -i or cpio -p .
-f
Copy in all files except those in patterns . Can only be used with cpio -i .
-l
Whenever possible, link files rather than copying them. Can only be used with cpio -p .
-m
Retain previous modification times. This option is ineffective on directories that are being copied. Can only be used with cpio -i or cpio -p .
-r
Interactively rename files. The user is asked whether to rename pattern each invocation. Read and write permissions for /dev/tty are required for this option. If the user types a null line, the file is skipped. Should only be used with cpio -i or cpio -o .
-t
Print a table of contents of the input. No files are created. Can only be used with cpio -i .
-u
Copy files unconditionally; usually an older file will not replace a new file with the same name. Can only be used with cpio -i or cpio -p .
-v
Verbose: cause the names of the affected files to be printed. Can only be used with cpio -i . Provides a detailed listing when used with the -t option.
 

Operands

The following operands are available:
patterns
Simple regular expressions given in the name-generating notation of the shell.
directory
The destination directory.
 

Exit Status

The cpio utility exits with one of the following values:
0
All input files were copied.
2
The utility encountered errors in copying or accessing files or directories. An error will be reported for nonexistent files or directories, or permissions that do not allow the user to access the source or target files.
 

It is important to use the

-depth option of the find utility to generate pathnames for cpio . This eliminates problems cpio could have trying to create files under read-only directories.

The following command:

ls | cpio -o > ../newfile
copies out the files listed by the ls utility and redirects them to the file newfile .

The following command:

cat newfile | cpio -id "memo/al" "memo/b*"
uses the output file newfile from the cpio -o utility, takes those files that match the patterns memo/al and memo/b* , creates the directories below the current directory, and places the files in the appropriate directories.

The command

find . -depth -print | cpio -pdlmv newdir
takes the file names piped to it from the find utility and copies or links those files to another directory named newdir , while retaining the modification time.  

FILES

/dev/tty
used to prompt the user for information when the -i or -r options are specified.
 

SEE ALSO

find(1), pax(1), tar(1), cpio(5), tar(5)  

COPYRIGHT

Copyright (c) 1989 Mark H. Colburn.
All rights reserved.

Redistribution and use in source and binary forms are permitted provided that the above copyright notice is duplicated in all such forms and that any documentation, advertising materials, and other materials related to such distribution and use acknowledge that the software was developed by Mark H. Colburn and sponsored by The USENIX Association.

THE SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.  

AUTHOR

Mark H. Colburn
NAPS International
117 Mackubin Street, Suite 1
St. Paul, MN 55102
mark@jhereg.MN.ORG

Sponsored by The USENIX Association for public distribution.


 

Index

NAME
SYNOPSIS
DESCRIPTION
Options
Operands
Exit Status
It is important to use the
FILES
SEE ALSO
COPYRIGHT
AUTHOR

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Time: 18:22:39 GMT, January 07, 2023