#!/usr/bin/perl

#
# Check for nexted HTML tags.
#

#
# These tags are typically not closed, so don't 
# bother to keep track of them.
%nocheck = (
  "p", 1,
  "br", 1,
  "td", 1,
  "tr", 1,
  "col", 1,
  "li", 1,
);

foreach $f (@ARGV) {
  open(INPUT, $f) || die "$f: $!";
  @context = ();
  $line = 0;
  while (<INPUT>) {
    $line++;
    y/A-Z/a-z/;
    while (s/<([\/\w]+)[^>]*>//) {
      $html = $1;
      $end = ($html =~ s:/::);
      next if $nocheck{$html};
      if ($end) {
        $context = pop(@context);
        warn "Got /$html, expected /$context in $f, line $line\n"
          unless $html eq $context;
      } else {
        push(@context, $html);
      }
    }
  }
}