32v 1m tar

TAR(1) UNIX Programmer's Manual TAR(1)

NAME

    tar  -  tape archiver

SYNOPSIS

    tar [ key ] [ name ... ]

DESCRIPTION

    _T_a_r saves and restores files on magtape.  Its actions are
    controlled by the _k_e_y argument.  The _k_e_y is a string of
    characters containing at most one function letter and possi-
    bly one or more function modifiers.  Other arguments to the
    command are file or directory names specifying which files
    are to be dumped or restored.  In all cases, appearance of a
    directory name refers to the files and (recursively) sub-
    directories of that directory.

    The function portion of the key is specified by one of the
    following letters:

    r       The named files are written on the end of the tape.
            The c function implies this.

    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 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.

    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.

    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.

    c       Create a new tape; writing begins on the beginning
            of the tape instead of after the last file.  This
            command implies r.

    The following characters may be used in addition to the
    letter which selects the function desired.

    0,...,7   This modifier selects the drive on which the tape
              is mounted.  The default is 1.

    v         Normally _t_a_r does its work silently.  The v (ver-
              bose) option causes it to type the name of each
              file it treats preceded by the function letter.
              With the t function, v gives more information
              about the tape entries than just the name.

    w         causes _t_a_r to print the action to be taken fol-
              lowed by file name, then wait for user confirma-
              tion. If a word beginning with `y' is given, the
              action is performed. Any other input means don't
              do it.

    f         causes _t_a_r to use the next argument as the name of
              the archive instead of /dev/mt?. If the name of
              the file is `-', tar writes to standard output or
              reads from standard input, whichever is appropri-
              ate. Thus, _t_a_r can be used as the head or tail of
              a filter chain _T_a_r can also be used to move
              hierarchies with the command
                cd fromdir; tar cf - . | (cd todir; tar xf -)

    b         causes _t_a_r to use the next argument as the block-
              ing factor for tape records. The default is 1, the
              maximum is 20. This option should only be used
              with raw magnetic tape archives (See f above).

    l         tells _t_a_r to complain if it cannot resolve all of
              the links to the files dumped. If this is not
              specified, no error meesages are printed.

FILES

    /dev/mt?
    /tmp/tar*

DIAGNOSTICS

    Complaints about bad key characters and tape read/write
    errors.
    Complaints if enough memory is not available to hold the
    link tables.

BUGS

    There is no way to ask for the _n-th occurrence of a file.
    Tape errors are handled ungracefully.
    The u option can be slow.
    The b option should not be used with archives that are going
    to be updated. The current magtape driver cannot backspace
    raw magtape.  If the archive is on a disk file the b option
    should not be used at all, as updating an archive stored in
    this manner can destroy it.
    The current limit on file name length is 100 characters.