#!/usr/bin/perl

$_ = ",,,,";
print "Good\n" if /(?:[^,]*,\s*){3}(.*?)\s*,/;

##</code><code>##

print "$1\n" if /^(.+?)#,/;

##</code><code>##

#!/usr/bin/perl

$_ = "test1, test2#,test3";
print "$1\n" if /^(.+?)#,/;   # Returns a false positive
print "$1\n" if /^([^,]+)#,/; # This fails, as we expect