cpio

File Format
Name	cpio
Ontology	Electronic File Formats Archiving cpio
Extension(s)	.cpio
MIME Type(s)	application/x-cpio
PRONOM	fmt/635

cpio is a non-compressed file archive format for Unix-style systems. It was originally intended for tape archiving, similar to the Tape Archive (tar) format.

Examples

To extract files, using the command line utility:

 $ cpio -idmv -I example.cpio

To list files:

 $ cpio -it -I example.cpio

Identification

A cpio archive begins with one of the following signatures:

• 0x71 0xC7
• 0xC7 0x71
• '0' '7' '0' '7'

Be aware that there are afio extensions to cpio format that are not supported by most cpio utilities. For one thing, if most of the filenames end in ".z", it's probably a compressed afio archive.

Specifications

• cpio format man page

Software

• GNU cpio
• libarchive / bsdcpio
• cpio for Windows
• 7-Zip
• afio
• Konvertor
• Deark

Sample files

• http://ftp.gnu.org/gnu/tar/tar-1.27.cpio.gz
• dexvert samples — archive/cpio
• ClamAV Download → 0.103.8 Source → test/.split → split.clam.*.cpio??

Other links

• Wikipedia article
• cpio utility man page
• GNU cpio manual
• tar vs. cpio
• ForensicsWiki entry (no useful detail)