cpio(1)cpio(1)NAMEcpio - copy file archives in and out; duplicate directory trees
The command saves and restores archives of files on magnetic tape,
other devices, or a regular file, and copies files from one directory
to another while replicating the directory tree structure. When com‐
pletes processing the files, it reports the number of blocks written.
(copy out, export)
Read standard input to obtain a list of path names, and
copy those files to standard output together with path name
and status information. The output is padded to a 512-byte
(copy in, import)
Extract files from standard input, which is assumed to be
the result of a previous
If pattern..., is specified, only the files with names that
match a pattern according to the rules of Pattern Matching
Notation (see regexp(5)) are selected. A leading on a pat‐
tern indicates that only those names that do not match the
remainder of the pattern should be selected. Multiple pat‐
terns can be specified. The patterns are additive. If no
pattern is specified, the default is (select all files).
See the option, as well.
Extracted files are conditionally created and copied into
the current directory tree, as determined by the options
described below. The permissions of the files match the
permissions of the original files when the archive was cre‐
ated by unless the option is used. File owner and group
are that of the current user unless the user has appropri‐
ate privileges, in which case retains the owner and group
of the files of the previous
Read standard input to obtain a list of path names of files
which are then conditionally created and copied into the
destination directory tree as determined by the options
described below. directory must exist. Destination path
names are interpreted relative to directory.
With the option, when handling a link, only the link is
passed and no data blocks are actually read or written.
This is especially noteworthy with where it is very possi‐
ble that all the files are created as links, such that no
blocks are written and "0 blocks" is reported by (See below
for a description of the option.)
recognizes the following options, which can be appended as appropriate
to and White space and hyphens are not permitted between these options
Reset access times of input files after they are copied.
Swap both bytes and half-words.
Use only with See the option for details; see also the
Write or read header information in
ASCII character form for portability.
Create directories as needed.
Specifies the handling of any extent attributes of the file(s)
archived or copied. extarg takes one of the following
Archive or copy the file and issue a warning message
if extent attributes
cannot be preserved.
Do not issue a warning message even if extent
attributes cannot be
Any file(s) with extent attributes will not be
archived and a warning
message will be issued.
When using the option, extent attributes are not pre‐
served in the archive. Furthermore, the option will
not preserve extent attributes if the files are being
copied to a file system that does not support extent
attributes. If is not specified, the default value
for extarg is
Copy in all files except those selected by
Follow symbolic links as though they were normal files or direc‐
Normally, archives the link.
Whenever possible, link files rather than copying them.
This option does not destroy existing files. Use only
Retain previous file modification time.
This option does not affect directories that are being
Provides support for large user/group IDs.
will recognise the option when HP's optional product
is installed on the system. When this option is used
with the and options, the user/group IDs of the files
that have user/group IDs greater than 60 KB are
retained. Note that archives created with the option
must be extracted with the option. Also note that the
command cannot read archives created with the option.
Rename files interactively.
If the user types a null line, the file is skipped.
Swap all bytes of the file.
Use only with See the option for details; see also the
Print only a table of contents of the input.
No files are created, read, or copied.
(normally, an older file does not replace a newer file
with the same name).
Print a list of file names as they are processed.
When used with the option, the table of contents has
numeric-mode owner-name blocks date-time filename
where numeric-mode is the file privileges in numeric
format, owner-name is the name of the file owner,
blocks is the size of the file in 512-byte blocks,
date-time is the date and time the file was last modi‐
fied, and filename is the path name of the file as
recorded in the archive.
Save or restore device special files.
Since is used to recreate these files on a restore,
and can be used only by users with appropriate privi‐
leges (see mknod(2)). This option is intended for
intrasystem (backup) use only. Restoring device files
from previous versions of the OS, or from different
systems can be very dangerous. may prevent the
restoration of certain device files from the archive.
Suppress warning messages regarding optional access control list
entries. does not back up optional access control
list entries in a file's access control list (see
acl(5)). Normally, a warning message is printed for
each file that has optional access control list
Block input/output at 5120 bytes to the record (does not apply
This option is meaningful only with data directed to
or from devices that support variable-length records
such as magnetic tape.
Have checkpoint itself at the start of each volume. If is
writing to a streaming tape drive with immediate-
report mode enabled and a write error occurs, it nor‐
mally aborts and exits with return code With this
option specified, instead automatically restarts
itself from the checkpoint and rewrites the current
volume. Alternatively, if is not writing to such a
device and a write error occurs, normally continues
with the next volume. With this option specified,
however, the user can choose to either ignore the
error or rewrite the current volume.
Read a file written on a
PDP-11 or VAX system (with byte-swapping) that did not
use the option. Use only with Files copied in this
mode are not changed. Non-ASCII files are likely to
need further processing to be readable. This process‐
ing often requires knowledge of file contents, and
thus cannot always be done by this program. The and
options can be used when swapping all the bytes on the
tape (rather than just in the headers) is appropriate.
In general, text is best processed with and binary
data with one of the other options.
Resynchronize automatically when
goes "out of phase", (see the section).
Swap all half-words in the file.
Use only with See the option for details; see also the
Use the process's file-mode creation mask (see
umask(2)) to modify the mode of files created, in the
same manner as creat(2).
Process a UNIX Sixth-Edition-format file. Use only with
Note that archives created using a raw device file must be read using a
raw device file.
When the end of the tape is reached, prompts the user for a new special
file and continues.
If you want to pass one or more metacharacters to without the shell
expanding them, be sure to precede each of them with a backslash
Device files written with the option (such as do not transport to other
implementations of HP-UX.
determines the collating sequence used in evaluating pattern matching
notation for file name generation.
determines the interpretation of text as single and/or multi-byte char‐
acters, and the characters matched by character class expressions in
pattern matching notation.
determines the format and content of date and time strings output when
listing the contents of an archive with the option.
determines the language in which messages are displayed.
If or is not specified in the environment or is set to the empty
string, the value of is used as a default for each unspecified or empty
variable. If is not specified or is set to the empty string, a default
of "C" (see lang(5)) is used instead of If any internationalization
variable contains an invalid setting, behaves as if all international‐
ization variables are set to "C". See environ(5).
International Code Set Support
Single- and multibyte character code sets are supported.
returns the following exit codes:
Review standard error for files that could not be trans‐
Error during resynchronization.
Some files may not have been recovered.
A file header is corrupt or in the wrong format.
could not read the header of an archived file.
The header is corrupt or it was written in a different
format. Without the option, returns an exit code of
If no file name has been displayed yet, the problem may
be the format. Try specifying a different header format
option: null for standard format; for ASCII; or for one
of the byte-swapping formats; or for UNIX Sixth Edition.
Otherwise, a header may be corrupt. Use the option to
have attempt to resynchronize the file automatically.
Resynchronizing means that tries to find the next good
header in the archive file and continues processing from
there. If tries to resynchronize from being out of
phase, it returns an exit code of
Other diagnostic messages are self-explanatory.
Copy the contents of a directory into a tape archive:
Duplicate a directory hierarchy:
The trivial case
can be handled more efficiently by:
Because of industry standards and interoperability goals, does
not support the archival of files larger than 2 GB or files that
have user/group IDs greater than 60 K. Files with user/group
IDs greater than 60 K are archived and restored under the
user/group ID of the current process.
Do not redirect the output of to a named archive file residing
in the same directory as the original files belonging to that
archive. This can cause loss of data.
strips any leading characters in the list of file names piped to
Path names are restricted to characters (see and limits(5)). If
there are too many unique linked files, the program runs out of
memory to keep track of them. Thereafter, linking information
is lost. Only users with appropriate privileges can copy spe‐
tapes written on HP machines with the options can sometimes mis‐
lead (non-HP) versions of that do not support the option. If a
non-HP (or non-AT&T) version of happens to be modified so that
the (HP) recognizes it as a device special file, a spurious
device file might be created.
If is not accessible, issues a complaint and exits.
The option does not create the directory typed on the command
The option does not make empty directories.
The option does not link files to existing files.
POSIX defines a file named as an end-of-archive marker. Conse‐
quently, if a file of that name is contained in a group of files
being written by the file is interpreted as end-of-archive, and
no remaining files are copied. The recommended practice is to
avoid naming files anything that resembles an end-of-archive
To create a POSIX-conforming archive, the option must be used.
To read a POSIX-conforming archive, the option must be used and
the and options should not be used. If the user does not have
appropriate privileges, the option must also be used to get
POSIX-conforming behavior when reading an archive. Users with
appropriate privileges should not use this option to get POSIX-
If the path given to contains a symbolic link as the last ele‐
ment, this link is traversed and path name resolution continues.
uses the symbolic link's target, rather than that of the link.
SEE ALSOar(1), find(1), tar(1), mksf(1M), cpio(4), acl(5), environ(5),
lang(5), regexp(5), mt(7).