scpio(1)

NAME

scpio - copy file archives in and out (LEGACY)

SYNOPSIS

scpio [ other options ] -o[aBcv]
scpio [ other options ] -i[Bcdmruvf] [ pattern ...  ]
scpio [ other options ] -it[Bcvf] [ pattern ...  ]
scpio [ other options ] -p[adlmuv] directory

DESCRIPTION

The scpio utility, depending on the options used:

� copies files to an archive file

� extracts files from an archive file

� lists files from an archive file

� copies files from one directory tree to another.

OPTIONS

The scpio utility supports the XBD specification Utility
Syntax Guidelines. The cpio standard does not allow the option
modifiers to be presented as separate arguments from the option
letters. The scpio implementation allows option modifiers to be
presented as separate arguments from the option letters. When
writing portable shell scripts do never make use of this feature.
The following options are supported:
-o (Copy Out.) Read the standard input to obtain a
list of pathnames and copy those files onto the standard output
together with pathname and status information. Output is padded
to a 512-byte boundary.
-i (Copy In.) Extract files from the standard input,
which is assumed to be the product of a previous scpio -o. Only
files with names that match patterns are selected. The extracted
files are conditionally created and copied into the current di
rectory tree based upon the options described below. The permis
sions of the files will be those of the previous scpio -o. The
owner and group of the files will be that of the current user un
less the user has appropriate privileges, which causes scpio to
retain the owner and group of the files of the previous scpio -o.
If the archive being read does not match the modifier specified,
scpio may consider this to be an error and exit or may recognise
the archive and continue processing. Only a user with appropriate
privileges can extract block special or character special files
from an archive.
-it (List.) List files from the archive. This is a sub
mode of the copy in mode, no files are created in list mode.
-p (Pass.) Read the standard input to obtain a list of
pathnames of files that are conditionally created and copied into
the destination directory tree based upon the option modifiers
described below.
The following option modifiers can be appended in any se
quence to the -o, -i or -p options:
a Reset access times of input files after they have
been copied. (When option l (see below) is also specified, the
access times of the linked files are not reset.)
B Block input/output 5120 bytes to the record (does
not apply to the -p option; meaningful only with data directed to
or from character special files).
d Create directories as needed.
c Write or read header information in character form
for portability. Note that the Open Group standard does not
specify the archive format that should be used with the c option.
For this reason it is questionable wether the c option increases
portability in general.: The archive format used by scpio with the c option; is the format from the -H asc option. It gives best cpio compat; ibility when transferring files to SVR4-based systems (except; that the file size is limited to 2 gigabytes). When transferring; files in cpio archives to unknown operating systems, it is unwise; to use the c option.
r Interactively rename files. For each archive member
matching pattern operand, a prompt will be written to the file
/dev/tty. The prompt will contain the name of the archive mem
ber, but the format is otherwise unspecified. A line will then be
read from /dev/tty. If this line is blank, the archive member
will be skipped. If this line consists of a single period, the
archive member will be processed with no modification to its
name. Otherwise, its name will be replaced with the contents of
the line. The scpio utility will immediately exit with a non-zero
exit status if end-of-file is encountered when reading a re
sponse, or if /dev/tty cannot be opened for reading and writing.
t Write 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: print the names of the affected files.
With the t option, provides a detailed listing.
l Whenever possible, link files rather than copying
them. Usable only with the -p option. The l option modifier is
not yet supported by scpio.
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.
The following other options are implemented as SVr4
compliant extension to the Open Group standard:
-6 Extract UNIX System Sixth Edition cpio archives.
This option is not valid in archive create mode, it is mutually
exclusive with -c, -H, and artype=. As is is unclear how UNIX

System Sixth Edition

rently unsupported.
-@ Include extended file attributes in the archive.
This option is currently unsupported.
-A Append files to an existing archive. The -A option
only works together with the -O option. See star -r for more in
formation.
-b Reverses the order of the bytes within each word.
It is unclear what a word is supposed to be. This option is un
supported but not needed as scpio includes automatic byte order
recognition.
-C # Sets (input/output) archive block size to # bytes.
-E name: Read filenames for store/create/list command from; name. The file name must contain a list of filenames, each on a; separate line.
-H header: Set the archive type to header. See star(1) for; more information.
-I nm Use nm as archive file name instead of stdin.
-k Try to skip corrupt archive headers.
-L Follow symbolic links as if they were files.
-M message: Define a message that is uses when switching media.; This option is currently unsupported.
-O nm Use nm as archive file name instead of stdout.
-P Handle Access Control List (ACL) information in
create and extract mode. See star -acl for more information.
-R nm Reassign ownership and group for all files based on
nm. This option is currently unsupported.
-s Reverses the order of the bytes within each word.
It is unclear what a word is supposed to be. This option is un
supported but not needed as scpio includes automatic byte order
recognition.
-S Reverses the order of the halfwords within each
word. It is unclear what a word is supposed to be. This option
is unsupported but not needed as scpio includes automatic byte
order recognition.
-V Special verbose. Print a dot for each file that is
read or written. This option is currently unsupported.
The following other options are implemented as star exten
sion to the Open Group standard:
-help Prints a summary of the most important options for
scpio(1) and exits.
-xhelp Prints a summary of the less important options for
scpio(1) and exits.
-version: Prints the scpio version number string and exists.
-/ Don't strip leading slashes from file names when
extracting an archive. See star(1) for more information.
.. Don't skip files that contain /../ in the name.
See star(1) for more information.
-acl Handle Access Control List (ACL) information in
create and extract mode. See star(1) for more information.
artype=header: Set the archive type to header. See star(1) for; more information.
-bz Run the input or output through a bzip2 pipe - see
option -z below. As the -bz the -z options are non standard, it
makes sense to omit -bz options the inside shell scripts. If you
are going to extract a compressed archive that is located inside
a plain file, scpio will auto detect compression and choose the
right decompression option to extract.
bs=# Set block size to #. You may use the same method as
in dd(1) and sdd(1). See star(1) for more information.
-fifostats: Print fifo statistics at the end of a scpio run; when the fifo has been in effect.
fs=# Set fifo size to #. See star(1) for more informa
tion.
-no-fifo: Do not use a fifo to optimize data flow from/to; tape. See star(1) for more information.
-no-fsync: Do not call fsync(2) for each file that has been; extracted from the archive. See star(1) for more information.
-no-statistics: Do not print statistic messages at the end of a; scpio run.
-secure-links: Do not extract hard links or symbolic links if the; link name (the target of the link) starts with a slash (/) or if; /../ is contained in the link name. See star(1) for more infor; mation.
-numeric: Use the numeric user/group fields in the listing; rather than the default. See star(1) for more information.
-time Print timing info. See star(1) for more informa
tion.
-xfflags: Store and extract extended file flags as found on; BSD and Linux systems. See star -acl for more information.
-z Run the input or output through a gzip pipe - see
option -bz above. As the -bz the -z options are non standard, it
makes sense to omit -bz options the inside shell scripts. If you
are going to extract a compressed archive that is located inside
a plain file, scpio will auto detect compression and choose the
right decompression option to extract.

OPERANDS

The following operands are supported:

directory: A pathname of an existing directory to be used as; the target of scpio -p.
pattern: Expressions making use of a pattern-matching nota; tion similar to that used by the shell for filename pattern; matching, and similar to regular expressions. The following; metacharacters are defined:; * Matches any string, including the empty; string.; ? Matches any single character.; [...] Matches any one of the enclosed characters.; A pair of characters separated by `-' matches any symbol between; the pair (inclusive), as defined by the system default collating; sequence. If the first character following the opening `[' is a; `!', the results are unspecified.; In pattern, the special characters "?", "*" and "["; also match the "/" character. Multiple cases of pattern can be; specified and if no pattern is specified, the default for pattern; is "*" (that is, select all files).; Note that scpio does not use fnmatch(3) based pat; tern matching as documented above, it rather uses the pattern; matcher documented in match(1).

STDIN

When the -o or -p options are used, the standard input is
a text file containing a list of pathnames, one per line, to be
copied.
When the -i option is used, the standard input is an
archive file formatted in any way that is understood by the
archive handling engine (see -H help option for a complete list).

INPUT FILES

The files identified by the pathnames in the standard in
put are of any type.
When the -r option is used, the file /dev/tty is used to
write prompts and read responses.

ASYNCHRONOUS EVENTS

Default.

STDOUT

When the -o option is used, the standard output is an
archive file formatted as specified by pax with the -x cpio op
tion. For better compatibility with SVR4-based systems that do
not implement the cpio format correctly, scpio by default limits
the length of file names to 256 bytes. Use scpio -H cpio to ex
plicitly switch to the full POSIX 1003.1-1988 cpio archive for
mat.
Otherwise, the standard output contains commentary in an
unspecified format concerning the progress of the execution.

STDERR

When the -o option is not used, the standard error con
tains commentary in an unspecified format concerning the progress
of the execution. Otherwise, the standard error is used only for
diagnostic messages.

OUTPUT FILES

Output files are created, as specified by the archive,
when the -i or -p options are used.

EXTENDED DESCRIPTION

None.

EXIT STATUS

The following exit values are returned:

0 Successful completion.

>0 An error occurred.

CONSEQUENCES OF ERRORS

If a file or directory cannot be created or overwritten,
scpio continues with the next file in the archive or file to be
added to the archive.

APPLICATION USAGE

Archives created by scpio are portable between XSI-confor
mant systems provided the same procedures are used.
The shell metacharacter notation is not fully compatible
with that used by the shell and the pax utility. Not all systems
support the use of the negation character [! ...] in cpio pat
terns. Portable applications must avoid the use of this notation.
For portable communication of data between XSI-conformant
systems, it is recommended that only characters defined in the
ISO/IEC 646:1991 standard International Reference Version (equiv
alent to ASCII) 7-bit range of characters be used and that only
characters defined in the Portable Filename Character Set be used
for naming files. This recommendation is given because XSI-con
formant systems support diverse codesets and run in various geo
graphical areas and there is no single, well-established codeset
that incorporates all of the characters of the languages of the
various geographical areas.
The cpio archive format only supports file sizes up to 8
gigabytes.
Applications should migrate to the pax archive format
which is the POSIX 1003.1-2001 standard archive format and based
on an extended tar format.

FUTURE DIRECTIONS

None.

EXAMPLES

1. Copy the contents of a directory onto an archive:

ls | scpio -o >../cpio.out

2. Duplicate a directory hierarchy:

cd olddir
find . -depth -print | scpio -pd ../newdir

ENVIRONMENT

The following environment variables may affect the execu
tion of scpio:
TZ Determine the timezone used with date and time
strings.

DIAGNOSTICS NOTES

The default block size for cpio is 512 bytes, this slows
down write speed. Use -B, -C, or bs= to set a different block
size.
The Open Group, have given us permission to reprint por
tions of their documentation. In the following statement, the
phrase ``this text'' refers to portions of the system documenta
tion.
Portions of this text are reprinted and reproduced in
electronic form in the scpio manual, from The Open Group Base
the event of any discrepancy between these versions and the orig
inal specification, the original The Open Group Standard is the
referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/single_unix_specification_v2.

BUGS AUTHOR

Joerg Schilling
Seestr. 110
D-13353 Berlin
Germany

Mail bugs and suggestions to:

schilling@fokus.fraunhofer.de or js@cs.tu-berlin.de or
joerg@schily.isdn.cs.tu-berlin.de
Joerg Schilling 04/10/04

docs.sk

comprehensive documentation repository

See also