Quoth Leander Jedamus <ljeda...@gmail.com>:

- Don't call subs with '&' unless you need to.

- 'warn' is a builtin. Defining a sub with that name is a bad idea.

- `date -r` is not portable (on my system it does something quite
  different). Use stat() and POSIX::strftime.

- This

    sub mycopy
    {
      my $sdir      = $_[0];# source dir
      my $ddir      = $_[1];# destination dir
      my $sfiles    = $_[2];# the files to copy
      my $rekursive = $_[3];# if going recursive? (y/n)
      my $use_stamp = $_[4];# use stamp? (y/n)
      my $stamp     = $_[5];# the stamp
      my $warn      = $_[6];# warn level
      my $debug     = $_[7];#

  is a horrid mess. Learn how to use list assignment.

- mkdirhier is not portable (it's part of X, from the bad old days when
  mkdir didn't always understand -p). Use 'mkdir -p' (which ought to be)
  or File::Path (which definitely is).

- I can't follow the logic in 'mycopy' at all. It must be possible to
  write it without quite so many layers of ifs.

- I don't think there is a single comment in that program which makes
  anything clearer. Something like a general description of the logic
  implemented by the twisty maze of ifs in mycopy would have been much
  more useful than closing every sub with '};# sub foo'.

- Use multi-arg system

    system "cp", "-p", $sfile, $dfile;

  rather than trying to get shell quoting right. What if there's a file
  with " in its name?

After that I got bored, but is this really doing anything you can't do
with find -newer | xargs cp ? Or just forget the stamps and use rsync.