use strict;
use warnings;

for my $betrag ( qw/345.4 .34 123,456.45 .2/ ) {
    print "$betrag => ";
    my( $euro, $cent ) = split /\./, $betrag;
    $euro = '0' unless $euro;
    $euro =~ tr/,//d;
    $cent .= '0' while length $cent < 2;
    my $gesamt_cent = $euro . $cent;
    $gesamt_cent =~ s/^0+//;
    print "$gesamt_cent\n";
}