#! /bin/sed -nf
#
# Get the title of an HTML document.
# Look first for TITLE tag, then fall back on first Heading tag. Otherwise
# produce nothing.
#
# Casper Boden-Cummins <mister_pink@bigfoot.com>, 1998
#

/<[Tt][Ii][Tt][Ll][Ee]/ {
	:title
	# read up to closing tag
	/<\/[Tt][Ii][Tt][Ll][Ee]>/ !{
		N
		b title
	}

	# strip leading/trailing whitespace
	# Mario Niebaum <Mario.Niebaum@e-technik.tu-chemnitz.de>
	s/^.*<[tT][iI][tT][lL][eE]>[        ]*//
	s/[         ]*<\/[tT][iI][tT][lL][eE]>.*$//

	# strip HTML tags and print
	b print
}

/<[Hh][0-7]/ {
	:heading
	# lowercase heading tags
	s/\(<\/\{0,1\}\)[Hh]\([0-7]\)/\1h\2/g

	# strip characters up to opening tag
	G
	s/<h\([0-7]>\)\(.*\)\(.\)$/\3\1\2/
	s/.*\n/<h/

	:match_tags
	/^<h\([0-7]\).*<\/h\1/ !{
		N
		b match_tags
	}

	# strip leading/trailing whitespace
	s/^.*<[Hh][0-7]>[        ]*//
	s/[         ]*<\/[Hh][0-7]>.*$//

	# clean up and print
	b print
}

# nothing found, so continue to next line
b

# print:
# remove embedded tags and leading/trailing whitespace from
# pattern space, print result and quit
:print

# reduce leading/trailing whitespace around newlines
s/[ 	]*\n[	 ]*/ /g

# convert embedded TAGS to whitespace
s/[ 	]*<\/*[a-zA-Z0-9]\{1,\}>[	 ]*/ /g

# remove non-printable characters
s/[^ -;=?-~]//g

# strip leading/trailing whitespace from line
s/^[ 	]*\(.*[^ 	]\)[ 	]*$/\1/

# print and quit
p
q