in reply to How to specify a Null char in a match operation

Your CGI-params get html_unescaped when retrieving the value, i.e. the string %00 is converted to a _real_ ASCII NUL ("\0" in perl). Match that.
#!/usr/bin/perl -w use CGI; use strict; my $q = new CGI; print $q->header; print $q->start_html; my $p = $q->param('foo'); print $p =~ s/\0/�/g ? "$p - null char detected\n" : "$p fine.\n"; print $q->end_html; __END__ call e.g. with http://localhost/cgi-bin/foo.pl?foo=foo%00bar

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}