To add a string to a perl source file after the shebang line, my book says to do 
while (<>){
      if (/^#!/){
        $_ .= "Add this line.\n";
  }
}

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However this doesn't work. Instead, it erases the whole file. It makes sense that it should wok though, but for some reason it doesn't. Any idea why? thanks

In reply to To add a string to the content of a file by Babambar

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