#!/usr/bin/perl -wl
use strict;
# have to search a little differently for nested tags
# making sure that an ending tag belonging to
# a nested opening tag is not processed as the ending
# tag for the current opening tag.
# In case i sounded awkward, here's a little diagram:
#
# <cfif>     <--- this tag
#    <cfif>  <--- nested open tag
#    </cfif> <--- end tag for the nested open tag
# </cfif>    <--- end tag for this tag (the one that has
#                 to be picked up)
#

# Actual example:

my @chunks = ("<cfif bool eq 1>\cJ\cI ",
"<cfif foo = bar>\cJ\cI\cI  ",
"<cfif bar = foo>\cJ\cI\cI  ",
"</cfif>\cJ\cI ",
"</cfif>\cJ\cI\cI  \cJ\cI BOOL is true!\cJ",
"<cfelse>\cJ\cIBOOL is false!\cJ",
'</cfif>');

my $opening_tag = qr/\<cfif/;
my $closing_tag = qr/\<\/cfif/;
my $found_i = 0;
my $nested = 0; # count of nested open tags found.

while
(   (  ($chunks[++$found_i] =~ m/^$closing_tag/)
       ? (
           ($nested > 0)
           ? ($nested--)
           : (0)
         )
       : (
           ($chunks[$found_i] =~ m/^$opening_tag/)
           ? (++$nested)
           : (1)
         )
    )
    &&
    ( $found_i < @chunks )
)
{
    print "F: $found_i ",
          "N: $nested ",
          "C: $chunks[$found_i]",
          ;
}
__END__
F:\dev\vladb>perl nestag.pl
F: 1 N: 1 C: <cfif foo = bar>

F: 2 N: 2 C: <cfif bar = foo>

F: 3 N: 1 C: </cfif>

F: 4 N: 0 C: </cfif>

         BOOL is true!

F: 5 N: 0 C: <cfelse>
        BOOL is false!