#!/usr/bin/perl
  
$f = @ARGV[0] ; $m = @ARGV[1] ; $u = @ARGV[2] ; 

if (!$f || !$m || !$u) {
  print <<EOT;
$0 copyright 1996 Andrew Daviel, Vancouver-Webpages.com
This script is intended to reset the last-modified time
on files to make them cacheable for longer.
$0 takes 3 arguments, the name of the file to modify, the
amount of time, and the units, e.g.  "test.gif 3 weeks" 
EOT
  exit ;
}
%unit = ("week",7*24*3600,"day",24*3600,"month",31*24*3600,"year",365*24*3600,
  "hour",3600,"minute",60,"second",1) ;

open (FILE,$f) || die "Can't open input file $f" ;
@fstat=stat($f) ; # get stat

$u =~ s/s$// ;
$mu = $unit{$u} ;
unless ($mu) { die "Invalid units $u" ; }
$m = $m * $mu ;
$mtime = time -  $m ;
print "adjust time by $m to $mtime\n";
# $fstat[x] 2 mode, 4 uid 5 gid 7 size 8 atime 9 mtime 10 ctime
utime($fstat[8],$mtime,$f) || die "Can't change mtime for $f";
print "Updated file $f\n";