{
  local $/ = ";"; # local means perl will restore the value of $/ at the end of the block
                  # and the default behaviour when reading a file
  for my $file (@files)
  {
     # Note the $!, which contains the reason for the opening failure
     open my $fh, '<', $file or warn "Coudn't open $file: $!\n";
     while (<$fh>) # will stop at each ";", so read instruction by instruction
     {
       push @printfs, $1 if /(printf.*);/;
     }
  }
}