use strict;
my $str = '51.9499, 7.555780000000027; 51.49705, 9.389030000000048; 51.249182, 6.991165099999989; 47.3163508, 11.09513949999996; 51.33424979999999, 12.574196000000029; 50.0297493, 19.196331099999952; 47.8270212, 16.25014150000004; ';
my $regex = qr/;\s*/mp;
my $subst = ';\\n';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html