4.1cBSD/usr/man/man1/tar.1
.TH TAR 1 "13 January 1983"
.SH NAME
tar \- tape archiver
.SH SYNOPSIS
\fBtar\fP [ key ] [ name ... ]
.SH DESCRIPTION
.PP
\fITar\fP saves and restores multiple files on a single file (usually a magnetic
tape, but it can be any file).
.IR Tar 's
actions are controlled by the \fIkey\fP argument. The \fIkey\fP
is a string of characters containing at most one function letter and possibly
one or more function modifiers. Other arguments to \fItar\fP
are file or directory names specifying which files to dump or restore.
In all cases, appearance of a directory name refers to
the files and (recursively) subdirectories of that directory.
.PP
The function portion of the key is specified by one of the following letters:
.TP 8
.B r
The named files are written on the end of the tape. The
.B c
function implies this.
.TP 8
.B x
The named files are extracted from the tape. If the named file
matches a directory whose contents had been written onto the tape, this
directory is (recursively) extracted. The owner, modification time, and mode
are restored (if possible). If no file argument is given, the entire content
of the tape is extracted. Note that if multiple entries specifying the same
file are on the tape, the last one overwrites all earlier.
.TP 8
.B t
The names of the specified files are listed each time they occur on
the tape. If no file argument is given, all of the names on the tape
are listed.
.TP 8
.B u
The named files are added to the tape if either they are not
already there or have been modified since last put on the tape.
.TP 8
.B c
Create a new tape; writing begins on the beginning of the tape
instead of after the last file. This command implies
.BR r .
.TP 8
.B o
On output, tar normally places information specifying owner and modes
of directories in the archive. Former versions of tar, when encountering
this information will give error message of the form
.br
"<name>/: cannot create".
.br
This option will suppress the directory information.
.TP 8
.B p
This option says to restore files to their original modes,
ignoring the present umask(2). Setuid and sticky information
will also be restored to the super-user.
.PP
The following characters may be used in addition to the letter
which selects the function desired.
.TP 10
.B 0, ..., 9
This modifier selects an alternate drive on which the tape is mounted.
The default is drive 0 at 1600 bpi, which is normally /dev/rmt8.
.TP 10
.B v
Normally
.I tar
does its work silently. The
.B v
(verbose) option make
.I tar
type the name of each file it treats preceded by the function
letter. With the
.B t
function, the verbose option
gives more information about the tape entries than just their names.
.TP 10
.B w
.I Tar
prints the action to be taken followed by file name, then
wait for user confirmation. If a word beginning with `y'
is given, the action is done. Any other input means don't do it.
.TP 10
.B f
.I Tar
uses the next argument as the name of the archive instead of
/dev/rmt?. If the name of the file is `\-', tar writes to standard output or
reads from standard input, whichever is appropriate. Thus,
.I tar
can be used as the head or tail of a filter chain.
.I Tar
can also be used to move hierarchies with the command
.ce 1
cd fromdir; tar cf - . | (cd todir; tar xf -)
.TP 10
.B b
.I Tar
uses the next argument as the blocking factor for tape records. The
default is 20 (the maximum). This option should only be used with raw magnetic
tape archives (See
.B f
above). The block size is determined automatically
when reading tapes (key letters `x' and `t').
.TP 10
.B l
tells
.I tar
to complain if it cannot resolve all of the links to the
files dumped. If this is not specified, no error messages are printed.
.TP 10
.B m
tells
.I tar
not to restore the modification times. The modification time
will be the time of extraction.
.TP 10
.B h
Force
.I tar
to follow symbolic links as if they were normal files or
directories. Normally,
.I tar
does not follow symbolic links.
.TP 10
.B B
Forces input and output blocking to 20 blocks per record. This option
was added so that
.I tar
can work across a communications channel where the block may not
be maintained.
.PP
If a file name is preceded by
.BR \-C ,
then
.I tar
will perform a
.IR chdir (2)
to that file name. This allows multiple directories not
related by a close common parent to be archived using short
relative path names. For example, to archive files from /usr/include
and from /etc, one might use
.ce 1
tar c -C /usr include -C / etc
.PP
Previous restrictions dealing with
.IR tar 's
inability to properly handle blocked archives have been lifted.
.PP
.SH FILES
/dev/rmt?
.br
/tmp/tar*
.SH DIAGNOSTICS
Complaints about bad key characters and tape read/write errors.
.br
Complaints if enough memory is not available to hold the link tables.
.SH BUGS
There is no way to ask for the
.IR n -th
occurrence of a file.
.br
Tape errors are handled ungracefully.
.br
The
.B u
option can be slow.
.br
The current limit on file name length is 100 characters.
.br
There is no way to selectively follow symbolic links.
. \".SH MESSAGES
. \".IP "tar: usage tar -{txruB}[cvfblmh] [tapefile] [blocksize] file1 file2..." 5
. \".br
. \"This is the standard memory jogger message that tells you how to use
. \".IR tar .
. \"You will get this message if you just type a \fItar\fP
. \"command without arguments, or in several other places where \fItar\fP
. \"complains about something or other.
. \".IP "tar: x: unknown option" 5
. \".br
. \"You typed a \fItar\fP command line option which was not in the set of options
. \"that \fItar\fP knows about. Function letters are in the set c (create),
. \"o (xxxx), p (xxx), t (table of contents), u (update), and x (extract). Function
. \"modifiers are from the set b (specify blocksize), f (specify name of
. \"archive file), l (don't complain about missing links), m (use the
. \"extract time as the modification time), s (follow symbolic links), v
. \"(verbose), and B (force standard blocking for network operations).
. \".IP "tar: b: argument missing" 5
. \".br
. \"You specified the b (specify blocksize) function modifier but did not
. \"specify a blocksize.
. \".IP "Invalid blocksize nn." 5
. \".br
. \"You specified a blocksize which \fItar\fP
. \"cannot deal with. Blocksizes must be in the range of xxxxx-yyyyy.
. \".IP "tar: cannot get memory for blocksize nn" 5
. \".br
. \"\fITar\fP cannot obtain enough memory to handle the specified blocksize.
. \"Specify a smaller blocksize.
. \".IP "tar: f: argument missing" 5
. \".br
. \"You typed the f (specify name of archive file) function modifier on the
. \"command line but forgot the name of the archive file.
. \".IP "Tar: cannot create temporary file (\fIfilename\fP)" 5
. \".IP "Can only create standard output archives" 5
. \".br
. \".IP "tar: cannot open \fIfilename\fP" 5
. \".br
. \".IP "Missing links to \fIfilename\fP" 5
. \".IP "directory checksum error" 5
. \".IP "tar: \fIfilename\fP: cannot open file" 5
. \".IP "\fIfilename\fP: file name too long" 5
. \".br
. \"You specified a filename or a pathname which is longer than the maximum
. \"that \fItar\fP can handle. The current maximum length is 100 characters.
. \".IP "\fIfilename\fP: directory read error" 5
. \".br
. \".IP "tar: \fIfilename\fP is not a file. Not dumped" 5
. \".br
. \".IP "\fIfilename\fP: file name too long" 5
. \".br
. \".IP "\fIfilename\fP: symbolic link too long" 5
. \".br
. \".IP "a \fIfilename\fP " 5
. \".br
. \".IP "link to \fIfilename\fP" 5
. \".br
. \".IP "Out of memory. Link information lost" 5
. \".br
. \"\fITar\fP cannot store all the links to files. This only means that
. \"when the files are extracted again, the links won't be made.
. \".IP "\fIfilename\fP: file changed size" 5
. \".br
. \".IP "\fIfilename\fP: symbolic link failed" 5
. \".br
. \".IP "\fIfilename\fP: cannot link" 5
. \".br
. \".SH "INFORMATIVE MESSAGES"
. \".LP
. \"The messages below are those you get when you specify the v (verbose)
. \"option on the \fItar\fP command line.
. \".IP "a \fIfilename\fP nnnn blocks" 5
. \".br
. \"File \fIfilename\fP, of size \fInnnn\fP blocks, was added to the archive.
. \".IP "a \fIfilename\fP " 5
. \".br
. \".IP "symbolic link to \fIfilename\fP" 5
. \".br
. \".IP "x \fIfilename\fP, nnnn bytes, mmmm tape blocks" 5
. \".br
. \"A file was extracted, of \fInnnn\fP bytes in length, and of \fImmmm\fP
. \"tape blocks long.
. \".IP "\fIfile_1\fP linked to \fIfile_2\fP" 5
. \".br
. \".IP "x \fIfile_1\fP symbolic link to \fIfile_2\fP" 5
. \".br
. \".SH "DISASTER MESSAGES"
. \".LP
. \"There are a few messages which \fItar\fP
. \"displays when disaster strikes. Here they are.
. \".IP "tar: \fIfilename\fP: HELP - extract write error" 5
. \".br
. \".IP " linked to \fIfilename\fP" 5
. \".br
. \".IP " symbolic link to \fIfilename\fP" 5
. \".br
. \".IP "tar: cannot find mkdir!" 5
. \".br
. \"\fITar\fP needs to use the
. \".IR mkdir (1)
. \"utility to make directories, and it seems to be missing from the system.
. \".IP "\fIx\fP " 5
. \".br
. \".IP "\fIfilename\fP: " 5
. \".br
. \".IP "pwd failed!" 5
. \".br
. \".IP "/" 5
. \".br
. \".IP "Tar: tape read error" 5
. \".br
. \".IP "Tar: error, tape blocksize appears to be \fInnnn\fP bytes" 5
. \".br
. \".IP "Tar: blocksize = \fInnnn\fP" 5
. \".br
. \".IP "Tar: tape write error" 5
. \".br
. \".IP "Tar: tape write error" 5
. \".br
. \".IP "Tar: tape backspace error" 5
. \".br