NAME

cpio − copy file archives in and out

SYNOPSIS

cpio −o [ #aBchHLv ] [ name-list ]

cpio −i [ #BcdhHLmrtuvfsSb6 ] [ patterns ]

cpio −p [ adHLlmruv ] directory

DESCRIPTION

Cpio −o (copy out) uses the name-list arguments, or reads the standard input to obtain a list of pathnames and copies those files onto the standard output (or to the device /dev/rmt#) together with pathname and status information. 

Cpio −i (copy in) extracts files from the standard input (or from the device /dev/rmt#) which is assumed to be the product of a previous cpio −o.  Only files with names that match patterns are selected.  Patterns are given in the name-generating notation of sh(1). In patterns, meta-characters ?, ∗, and [...] match the slash / character.  Multiple patterns may be specified and if no patterns are specified, the default for patterns is ∗ (i.e., select all files).  The extracted files are conditionally created and copied into the current directory tree based upon the options described below. 

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

The meanings of the available options are:

# Use /dev/rmt# as input (for −i) or output (for −o).  Note: 6 has another meaning described below. 

a Reset access times of input files after they have been copied. 

B Input/output is to be blocked 5,120 bytes to the record (does not apply to the pass option; meaningful only with data directed to or from /dev/rmt?). 

c Write header information in ASCII character form for portability. 

d Directories are to be created as needed. 

H Don’t follow symbolic links.  This option is meaningful only with the o or p option.  Symbolic links, if any, are copied out as such.  This is the default. 

h Similar to B option, but block input/output to 250K bytes.  This option is only useful for streaming tape drive operation. 

L Follow symbolic links.  This option is meaningful only with the o or p option.  If symbolic links are encountered, the referenced files, rather than the symbolic links themselves, are copied out. 

r Interactively rename files.  If the user types a null line, the file is skipped. 

t Print a table of contents of the input.  No files are created. 

u Copy unconditionally (normally, an older file will not replace a newer file with the same name). 

v Verbose: causes a list of file names to be printed. When used with the t option, the table of contents looks like the output of an ls −l command (see ls(1)).

l Whenever possible, link files rather than copying them.  Usable only with the −p option. 

m Retain previous file modification time.  This option is ineffective on directories that are being copied. 

f Copy in all files except those in patterns.

s Swap bytes.  Use only with the −i option. 

S Swap halfwords.  Use only with the −i option. 

b Swap both bytes and halfwords.  Use only with the −i option. 

6 Process an old (i.e., UNIX System Sixth Edition format) file.  Only useful with −i (copy in). 

EXAMPLE

ls │ cpio −o >/dev/rmt1
or
cpio −o0 .

copies the contents of a directory into an archive;

cd olddir
find . −depth −print │ cpio −pdl newdir

duplicates a directory hierarchy. 

The trivial case “find . −depth −print │ cpio −oB >/dev/rmt1” can be handled more efficiently by:

find . −cpio /dev/rmt1

SEE ALSO

ar(1), find(1), symlink(2), cpio(4). 

BUGS

Spreading an archive over multiple tapes is not supported.  Inserting a second tape could cause the system to crash. 

Pathnames are restricted to 128 characters.  If there are too many unique linked files, the program runs out of memory to keep track of them and, thereafter, linking information is lost.  Only the superuser can copy special files.  The -B and -h options do not work with certain magnetic tape drives. 

Version 3.6  —  December 20, 1987