Your loop body is empty. In it, you can put this code:

copy "$source/$file", "$dest$file"
  or die "Can't copy file $file: $!";
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Also, I think you should check first to see if the inputted string is indeed a directory. Perhaps a check in the opendir call will work.

Plus, you code contains some stray code. Change this

opendir(DIR, $sech $file(@files){
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to

opendir(DIR, $source) 
  or die "Cannot opend the directory '$source': $!";
[download]