use strict;
my $str = 'urn:vcloud:user:2998042f-b91d-4c16-9de8-7feaf5e711a8
';
my $regex = qr/([a-zA-Z\:]){4,100}([a-zA-Z0-9]{8}[:-]([a-zA-Z0-9]{4}[:-]){3}[a-zA-Z0-9]{12})/p;
my $subst = '';
my $result = $str =~ s/$regex/$subst/r;
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