If you run that on its own then I would expect you will get no output at all because you don't print anything anywhere inside the loop. Perhaps what you want is:

while (<>){
      if (/^#!/){
        $_ .= "Add this line.\n";
  }
  print;
}

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DWIM is Perl's answer to Gödel

In reply to Re: To add a string to the content of a file by GrandFather
in thread To add a string to the content of a file by Babambar

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