source: trunk/essentials/sys-apps/texinfo/util/outline.gawk

#! /usr/local/bin/gawk -f

# texi.outline ---  produce an outline from a texinfo source file
# 
# Copyright (C) 1998 Arnold David Robbins (arnold@gnu.org)
# 
# TEXI.OUTLINE is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# 
# TEXI.OUTLINE is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA

# NOTE:
#       This program uses gensub(), which is specific to gawk.
#       With some work (split, substr, etc), it could be made to work
#       on other awks, but it's not worth the trouble for me.

BEGIN   \
{
        # Levels at which different nodes can be
        Level["@top"] = 0
        Level["@appendix"] = 1
        Level["@chapter"] = 1
        Level["@majorheading"] = 1
        Level["@unnumbered"] = 1
        Level["@appendixsec"] = 2
        Level["@heading"] = 2
        Level["@section"] = 2
        Level["@unnumberedsec"] = 2
        Level["@unnumberedsubsec"] = 3
        Level["@appendixsubsec"] = 3
        Level["@subheading"] = 3
        Level["@subsection"] = 3
        Level["@appendixsubsubsec"] = 4
        Level["@subsubheading"] = 4
        Level["@subsubsection"] = 4
        Level["@unnumberedsubsubsec"] = 4

        # insure that we were called correctly
        if (ARGC != 2) {
                printf("usage: %s texinfo-file\n", ARGV[0]) > "/dev/stderr"
                exit 1
        }

        # init header counters
        app_letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        app_h = 0
        l1_h = l2_h = l3_h = l4_h = 0
}

# skip lines we're not interested in
/^[^@]/ || ! ($1 in Level)      { next }

Level[$1] == 1  {
        if ($1 !~ /^@unnumbered/ || $1 !~ /heading/)
                l1_h++
        l2_h = l3_h = l4_h = 0
        Ntabs = 0
        Number = makenumber($1)
        Title = maketitle($0)
        print_title()
}

Level[$1] == 2  {
        l2_h++
        l3_h = l4_h = 0
        Ntabs = 1
        Number = makenumber($1)
        Title = maketitle($0)
        print_title()
}

Level[$1] == 3  {
        l3_h++
        l4_h = 0
        Ntabs = 2
        Number = makenumber($1)
        Title = maketitle($0)
        print_title()
}

Level[$1] == 4  {
        l4_h++
        Ntabs = 3
        Number = makenumber($1)
        Title = maketitle($0)
        print_title()
}

# maketitle --- extract title

function maketitle(str,         text)
{
        $1 = ""         # clobber section keyword
        text = $0
        gsub(/^[ \t]*/, "", text)
        text = gensub(/@[a-z]+{/, "", "g", text)
        text = gensub(/([^@])}/, "\\1", "g", text)
        return text
}

# print_title --- print the title

function print_title(   i)
{
        for (i = 1; i <= Ntabs; i++)
                printf "\t"
        printf("%s %s\n", Number, Title)
}

# makenumber --- construct a heading number from levels and section command

function makenumber(command,    result, lev1)
{
        result = ""
        if (command ~ /^@appendix/) {
                if (Level[command] == 1)
                        app_h++

                lev1 = substr(app_letters, app_h, 1)
        } else if (command ~ /^@unnumbered/ || command ~ /heading/) {
                lev1 = "(unnumbered)"
        } else
                lev1 = l1_h ""

        result = lev1 "."
        if (l2_h > 0) {
                result = result l2_h "."
                if (l3_h > 0) {
                        result = result l3_h "."
                        if (l4_h > 0) {
                                result = result l4_h "."
                        }
                }
        }
        return result
}