Method to check a string only contains ASCII characters #perl

is_within_ascii.pl

# is_within_ascii
#
# Returns a copy of the string if it is within ascii. If it is outside of the
# range, it will raise an error.

sub is_within_ascii {
  my $string = shift;

  # look for anything that isn't ascii or pass
  $string =~ /([^\x{00}-\x{7f}])/ or return $string;

  # explain why we failed
  my $dec = ord($1);
  my $hex = sprintf '%02x', $dec;

  die "$string -- char $+[0] not ASCII (it's $dec dec / $hex hex)\n";
}