#!/usr/bin/perl -w
#
use strict;

my @html = ("ö  -  ü  -  ä  -  ß  -  Ö  -  Ü  -  Ä");

foreach (@html) {
  convert_umlaut($_);
}

# convert_umlaut:
#
sub convert_umlaut {
  my $temp = shift;

  print "Vorher: $temp\n";

  $temp =~ s/ö/ö/g;
  $temp =~ s/ü/ü/g;
  $temp =~ s/ä/ä/g;
  $temp =~ s/ß/ß/g;
  $temp =~ s/Ö/Ö/g;
  $temp =~ s/Ü/Ü/g;
  $temp =~ s/Ä/Ä/g;

  print "Nacher: $temp\n";
}

<STDIN>;