Perl5 リファレンス

       utime LIST
               Changes the access and modification times on each
               file of a list of files.  The first two elements
               of the list must be the NUMERICAL access and
               modification times, in that order.  Returns the
               number of files successfully changed.  The inode
               change time of each file is set to the current
               time.  This code has the same effect as the
               `touch' command if the files already exist:

                   $now = time;
                   utime $now, $now, @ARGV;