

tar                          Command                          tar




Tape archive manager

ttaarr [ccrrttuuxx[00-77bbffllmmvvwwUU] [_b_l_o_c_k_s] [_a_r_c_h_i_v_e] _f_i_l_e ...

tar  manipulates archives  in a  machine-independent  format con-
venient for  tape.  The  first argument  consists of at  most one
directive character, followed  by zero or more option characters.
file is  generally a file to  be placed on or  extracted from the
tape.   If a  file  is a  directory, tar  processes its  contents
recursively.  For  directives that input  from the tape,  no file
specification tells  tar to process every file  on the tape.  For
directives that  output to the tape,  no file specification tells
tar to process every file in the current directory.

The directives are as follows:

cc  Create a new tape, overwriting any old contents.

rr  Replace (append) the named files on the tape.

tt  Write a table of contents of the tape to the standard output.

uu  Update  the tape by replacing the named  files which are newer
   (mtime larger) than any version on the tape.

xx  Extract  the named files  from the tape,  overwriting existing
   files with the same  names.  tar extracts each version of each
   file, leaving the latest version at the end.

The options are as follows:

00-77
   A single octal digit specifies  the unit on which the tape may
   be  found.  tar  concatenates this digit  to the  default tape
   name /dev/mt to form the path name accessed.

bb  The  next argument is a number between  one and 20, specifying
   how many  bblloocckkss are to  be written in each  tape record.  tar
   determines the  blocking factor automatically  on input.  When
   the  blocking  factor  is not  1,  the  default  tape name  is
   /dev/rmt (the raw device is used).

ff  The next  argument is the name of the  tape aarrcchhiivvee.  An argu-
   ment of '-' means  the standard input for input directives and
   the standard output for output directives.

ll  tar preserves links within the structure it writes to tape but
   breaks any  links across the boundary  of the structure.  This
   option requests that tar report all such broken links.

mm  Restore the mtime for each extracted file.

vv  Verbose flag.  If directive is t, the output for each file in-
   cludes its mode, group id,  user id, size, and mtime, in addi-


COHERENT Lexicon                                           Page 1




tar                          Command                          tar



   tion to  its path name.   Otherwise, tar writes  the directive
   and the path name  to the standard output for input directives
   or the  standard error for  output directives as  each file is
   processed.

ww  For  each file to  be processed, tar writes  the directive and
   path name to the terminal  device, then reads a line from that
   device and acts on it as follows:

   nn       Skip the file.
   yy       Process the file.
   xx       Exit immediately.

   An empty response is treated as  n, and end of file is treated
   as  x.   If  a directory  is  skipped,  all  its contents  are
   skipped.   If included,  all its  contents are  processed with
   this option.

UU   Non-COHERENT  systems  have  another implementation  of  this
   utility with  the following bug:  when the blocking  factor is
   not one, the last few blocks of the last record written may be
   garbage.  This  bug is described elsewhere  by other symptoms.
   This  option  says that  the  tape was  created  by the  buggy
   program, so the trailing garbage should be ignored.

***** Files *****

/ddeevv/mmtt* -- Default tape
/ddeevv/rrmmtt* -- Default tape for blocking factor greater than one

***** See Also *****

commands, dump, link(), restor, stat(), ustar

***** Notes *****

Path names  must be less than 100 characters.   The m option does
not affect directories.  The  only way to extract the Nth version
of a file is with the w option.

If the  m option  is used  to restore the  mtime of  an extracted
file, an  incremental dump may  not dump the file.   touch can be
used to force the dump.














COHERENT Lexicon                                           Page 2


