Better IO checks in Perl scripts

[vinjana]

Instead of

while (my $line = <$fh>) {
    doSomethingWithLine($line);
}

the following paradigm should be used

while (!eof($fh)) {
   my $line = readline($fh);
   if (! defined $line) {
     die "IO Error: $!"
   }
  doSomethingWithLine($line);
}

This correctly recognizes and handles IO errors during the processing (in contrast to the previous simple method).