strip

sharewall is very good

#! /bin/sh
#
# Script for use from Perl to strip config files and perform shell variable
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 2000,2001,2002,2003,2004,2005 - Tom Eastep ([e-mail])
#
#       Shorewall documentation is available at http://shorewall.net
#
#       This program is free software; you can redistribute it and/or modify
#       it under the terms of Version 2 of the GNU General Public License
#       as published by the Free Software Foundation.
#
#       This program 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
###############################################################################
# Filter that expands variables
#
expand_line() {
    local line

    while read line; do
	echo $(expand $line)
    done
}

#
# Read a file and handle "INCLUDE" directives
#

read_file() # $1 = file name, $2 = nest count
{
    local first
    local rest

    if [  -f $1 ]; then
	while read first rest; do
	    if [ "x$first"  = "xINCLUDE" ]; then
		if [ $2 -lt 4 ]; then
		    read_file $(find_file $(expand ${rest%#*})) $(($2 + 1))
		else
		    echo "   WARNING: INCLUDE in $1 ignored (nested too deeply)" >&2
		fi
	    else
		eval "$first $rest"
	    fi
	done < $1
    else
	echo "   WARNING -- No such file: $1" >&2
    fi
}

#
# Split a colon-separated list into a space-separated list
#
split() {
    local ifs
    ifs=$IFS
    IFS=:
    echo $*
    IFS=$ifs
}

#
# Find a File -- For relative file name, look in ${SHOREWALL_DIR} then each ${CONFIG_PATH} then ${CONFDIR}
#
find_file()
{
    local saveifs
    saveifs=
    local directory

    case $1 in
	/*)
	    echo $1
	    ;;
	*)
	    for directory in $(split $CONFIG_PATH); do
		if [ -f $directory/$1 ]; then
		    echo $directory/$1
		    return
		fi
	    done
	    
	    echo ${CONFDIR}/$1
	    ;;
    esac
}

#
# Strip comments and blank lines from a file and place the result in the
# temporary directory
#
if [ ! -f $TMP_DIR/$1 ]; then
    [ $# = 1 ] && fname=$(find_file $1) || fname=$2

    if [ -f $fname ]; then
	read_file $fname 0 | cut -d'#' -f1 | grep -v '^[[:space:]]*$' | expand_line > $TMP_DIR/$1
    else
	> $TMP_DIR/$1
    fi
fi