4mCPIO24m(1) General Commands Manual 4mCPIO24m(1) 1mNAME0m cpio — copy files to and from archives 1mSYNOPSIS0m 1mcpio -i 22m[4moptions24m] [4mpattern24m 4m...24m] [4m<24m 4marchive24m] 1mcpio -o 22m[4moptions24m] 4m<24m 4mname-list24m [4m>24m 4marchive24m] 1mcpio -p 22m[4moptions24m] 4mdest-dir24m 4m<24m 4mname-list0m 1mDESCRIPTION0m 1mcpio 22mcopies files between archives and directories. This implementa‐ tion 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 1mcpio 22mis a mode indicator from the following list: 1m-i 22mInput. Read an archive from standard input (unless overridden) and extract the contents to disk or (if the 1m-t 22moption 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. 1m-o 22mOutput. Read a list of filenames from standard input and pro‐ duce a new archive on standard output (unless overridden) con‐ taining the specified items. 1m-p 22mPass-through. Read a list of filenames from standard input and copy the files to the specified directory. 1mOPTIONS0m Unless specifically stated otherwise, options are applicable in all op‐ erating modes. 1m-022m, 1m--null0m Read filenames separated by NUL characters instead of newlines. This is necessary if any of the filenames being read might con‐ tain newlines. 1m-622m, 1m--pwb0m When reading a binary format archive, assume it's the earlier one, from the PWB variant of 6th Edition UNIX. When writing a cpio archive, use the PWB format. 1m-722m, 1m--binary0m (o mode only) When writing a cpio archive, use the (newer, non- PWB) binary format. 1m-A 22m(o mode only) Append to the specified archive. (Not yet imple‐ mented.) 1m-a 22m(o and p modes) Reset access times on files after they are read. 1m-B 22m(o mode only) Block output to records of 5120 bytes. 1m-C 4m22msize0m (o mode only) Block output to records of 4msize24m bytes. 1m-c 22m(o mode only) Use the old POSIX portable character format. Equivalent to 1m--format 4m22modc24m. 1m-d22m, 1m--make-directories0m (i and p modes) Create directories as necessary. 1m-E 4m22mfile0m (i mode only) Read list of file name patterns from 4mfile24m to list and extract. 1m-F 4m22mfile24m, 1m--file 4m22mfile0m Read archive from or write archive to 4mfile24m. 1m-f 4m22mpattern0m (i mode only) Ignore files that match 4mpattern24m. 1m-H 4m22mformat24m, 1m--format 4m22mformat0m (o mode only) Produce the output archive in the specified for‐ mat. Supported formats include: 4mcpio24m Synonym for 4modc24m. 4mnewc24m The SVR4 portable cpio format. 4modc24m The old POSIX.1 portable octet-oriented cpio format. 4mpax24m The POSIX.1 pax format, an extension of the ustar for‐ mat. 4mustar24m The POSIX.1 tar format. The default format is 4modc24m. See 4mlibarchive-formats24m(5) for more complete information about the formats currently supported by the underlying 4mlibarchive24m(3) library. 1m-h22m, 1m--help0m Print usage information. 1m-I 4m22mfile0m Read archive from 4mfile24m. 1m-i22m, 1m--extract0m Input mode. See above for description. 1m--insecure0m (i and p mode only) Disable security checks during extraction or copying. This allows extraction via symbolic links, ab‐ solute paths, and path names containing ‘..’ in the name. 1m-J22m, 1m--xz0m (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. 1m-j 22mSynonym for 1m-y22m. 1m-L 22m(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. 1m-l22m, 1m--link0m (p mode only) Create links from the target directory to the original files, instead of copying. 1m--lrzip0m (o mode only) Compress the resulting archive with 4mlrzip24m(1). In input mode, this option is ignored. 1m--lz4 22m(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. 1m--zstd 22m(o mode only) Compress the archive with zstd-compatible com‐ pression before writing it. In input mode, this option is ig‐ nored; zstd compression is recognized automatically on input. 1m--lzma 22m(o mode only) Compress the file with lzma-compatible compres‐ sion before writing it. In input mode, this option is ignored; lzma compression is recognized automatically on input. 1m--lzop 22m(o mode only) Compress the resulting archive with 4mlzop24m(1). In input mode, this option is ignored. 1m--passphrase 4m22mpassphrase0m The 4mpassphrase24m is used to extract or create an encrypted archive. Currently, zip is only a format that 1mcpio 22mcan handle encrypted archives. You shouldn't use this option unless you realize how insecure use of this option is. 1m-m22m, 1m--preserve-modification-time0m (i and p modes) Set file modification time on created files to match those in the source. 1m-n22m, 1m--numeric-uid-gid0m (i mode, only with 1m-t22m) Display numeric uid and gid. By de‐ fault, 1mcpio 22mdisplays 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. 1m--no-preserve-owner0m (i mode only) Do not attempt to restore file ownership. This is the default when run by non-root users. 1m-O 4m22mfile0m Write archive to 4mfile24m. 1m-o22m, 1m--create0m Output mode. See above for description. 1m-p22m, 1m--pass-through0m Pass-through mode. See above for description. 1m--preserve-owner0m (i mode only) Restore file ownership. This is the default when run by the root user. 1m--quiet0m Suppress unnecessary messages. 1m-R 22m[user][:][group], 1m--owner 22m[user][:][group] Set the owner and/or group on files in the output. If group is specified with no user (for example, 1m-R 4m22m:wheel24m) then the group will be set but not the user. If the user is specified with a trailing colon and no group (for example, 1m-R 4m22mroot:24m) 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 1m-i 22mand 1m-p 22mmodes, this option can only be used by the super-user. (For compatibility, a period can be used in place of the colon.) 1m-r 22m(All modes.) Rename files interactively. For each file, a prompt is written to 4m/dev/tty24m containing the name of the file and a line is read from 4m/dev/tty24m. 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. 1m-t22m, 1m--list0m (i mode only) List the contents of the archive to stdout; do not restore the contents to disk. 1m-u22m, 1m--unconditional0m (i and p modes) Unconditionally overwrite existing files. Or‐ dinarily, an older file will not overwrite a newer file on disk. 1m-V22m, 1m--dot0m Print a dot to stderr for each file as it is processed. Super‐ seded by 1m-v22m. 1m-v22m, 1m--verbose0m Print the name of each file to stderr as it is processed. With 1m-t22m, provide a detailed listing of each file. 1m--version0m Print the program version information and exit. 1m-y 22m(o mode only) Compress the archive with bzip2-compatible com‐ pression before writing it. In input mode, this option is ig‐ nored; bzip2 compression is recognized automatically on input. 1m-Z 22m(o mode only) Compress the archive with compress-compatible compression before writing it. In input mode, this option is ignored; compression is recognized automatically on input. 1m-z 22m(o mode only) Compress the archive with gzip-compatible com‐ pression before writing it. In input mode, this option is ig‐ nored; gzip compression is recognized automatically on input. 1mEXIT STATUS0m The 1mcpio 22mutility exits 0 on success, and >0 if an error occurs. 1mENVIRONMENT0m The following environment variables affect the execution of 1mcpio22m: LANG The locale to use. See 4menviron24m(7) for more information. TZ The timezone to use when displaying dates. See 4menviron24m(7) for more information. 1mEXAMPLES0m The 1mcpio 22mcommand is traditionally used to copy file hierarchies in con‐ junction with the 4mfind24m(1) command. The first example here simply copies all files from 4msrc24m to 4mdest24m: 1mfind 4m22msrc24m | 1mcpio -pmud 4m22mdest0m By carefully selecting options to the 4mfind24m(1) command and combining it with other standard utilities, it is possible to exercise very fine control over which files are copied. This next example copies files from 4msrc24m to 4mdest24m that are more than 2 days old and whose names match a particular pattern: 1mfind 4m22msrc24m 1m-mtime 4m22m+224m | 1mgrep foo[bar] 22m| 1mcpio -pdmu 4m22mdest0m This example copies files from 4msrc24m to 4mdest24m that are more than 2 days old and which contain the word “foobar”: 1mfind 4m22msrc24m 1m-mtime 4m22m+224m | 1mxargs grep -l foobar 22m| 1mcpio -pdmu 4m22mdest0m 1mCOMPATIBILITY0m 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 1m-i22m, 1m-o22m, and 1m-p 22mwere inter‐ preted as command-line options. Each took a single argument of a list of modifier characters. For example, the standard syntax allows 1m-imu0m but does not support 1m-miu 22mor 1m-i -m -u22m, since 4mm24m and 4mu24m are only modifiers to 1m-i22m, they are not command-line options in their own right. The syn‐ tax supported by this implementation is backwards-compatible with the standard. For best compatibility, scripts should limit themselves to the standard syntax. 1mSEE ALSO0m 4mbzip224m(1), 4mgzip24m(1), 4mmt24m(1), 4mpax24m(1), 4mtar24m(1), 4mlibarchive24m(3), 4mcpio24m(5), 4mlibarchive-formats24m(5), 4mtar24m(5) 1mSTANDARDS0m 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. 1mHISTORY0m The original 1mcpio 22mand 1mfind 22mutilities 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 Sys‐ tem III Unix in 1981. As a result, 1mcpio 22mactually predates 1mtar22m, even though it was not well-known outside of AT&T until some time later. This is a complete re-implementation based on the 4mlibarchive24m(3) li‐ brary. 1mBUGS0m 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 num‐ bers to 16 or 18 bits, which is insufficient for modern systems. The cpio archive formats cannot support files over 4 gigabytes, except for the “odc” variant, which can support files up to 8 gigabytes. Debian September 16, 2014 4mCPIO24m(1)