You use the utime() function documented in perlfunc/utime. By way of example, here's a little program that copies the read and write times from its first argument to all the rest of them.
if (@ARGV < 2) {
die "usage: cptimes timestamp_file other_files ...\n";
}
$timestamp = shift;
($atime, $mtime) = (stat($timestamp))[8,9];
utime $atime, $mtime, @ARGV;Error checking is, as usual, left as an exercise for the reader.
Note that utime() currently doesn't work correctly with Win95/NT ports. A bug has been reported. Check it carefully before using utime() on those platforms.