use strict;
my $str = 'a:4:{i:0;s:4:"a’";i:1;s:6:"abcdef";i:2;s:5:"abcde";i:3;s:3:"xyz";}';
my $regex = qr/i:\d+;s:\d+:"([^"]*)";/mp;
my $subst = '';
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