#! perl5
#
# tgz.pl Daniel Brockman 20031219 makes or extracts a tarred, gzipped file
#
# Warning: tgz.pl will overwrite existing files, if any.

################################################
# The author grants permission to use for any  #
# purpose, including copying and modification, #
# provided the user acknowledges the author by #
# name.                                        #
# -- Daniel Brockman, author, 20031220         #
################################################
#
# Usage: 
#
# To compress...
#
#     tgz.pl target [ zipname ]
#
#     will store the compressed content of target, including subdirectories
#     in file zipname.tgz . If zipname is omitted from command, then
#     zipname defaults to target.
#
# To display a catalog of the contents of a compressed file...
#
#    tgz.pl -t zipname
#
# To decompress...
#
#    tgz.pl -d zipname
#
# Dependencies: tar gzip

use strict "subs";
use strict "vars";

my ( $target,
     $zipname, 
     $ziptgz,
     $cmd,
     );

if($#ARGV<0){ 
	print "Usage: tgz.pl target \[zipname\]\n";
	print "   or: tgz.pl \[-t\|-d] zipname\]\n";
	print "Advice: use -t before using -d.";

}else{

  if(($#ARGV>0) and (($ARGV[0] eq "-d") or ($ARGV[0] eq "-t"))) {
    $zipname=$ARGV[1];
    $ziptgz=$zipname."\.tgz" ;
  
    if( -f $zipname & ! -f $ziptgz) {
      $ziptgz=$zipname ;
    }
  
    if(! -f $ziptgz){ 
	    die "File $ziptgz does not exist.";
    }
  
    if ($ARGV[0] eq "-d"){
      $cmd="gzip -d < $ziptgz | tar xf -";
    }else{
      $cmd="gzip -d < $ziptgz | tar tf -";
    }

  
  }else{

    # at this point we know it's not catalog nor decompression,
    # so only compression remains
    #
    
    $target=$ARGV[0];
    if($#ARGV>0){
      $ziptgz=$ARGV[1];
    }else{
      $ziptgz=$target."\.tgz";
    }
    if(! -x $target){
    	die "$target does not exist.";
    }
    $cmd="tar cf - $target | gzip -9fn > $ziptgz";

  }

  print "executing $cmd \n";
  system($cmd);  # execute command

}
    
# end