use strict;
my $str = '00.00
00002.0
3.00
-4.0
0.00
-0.00
0.03
2.01
0.001
-0.03
101
0.001
-0.03
.50
00.00
11.000000';
my $regex = qr/-?0+\.(0)+\b|\.0+\b|\b0+(?=\.\d*[1-9])|\b0+(?=[1-9]\d*\.)|(\.\d*?)0+\b/p;
my $subst = '$1$2';
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