i-bash/examples/functions/inetaddr

#
#  Chet Ramey <chet.ramey@case.edu>
#
#  Copyright 2002 Chester Ramey
#
#   This program 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, or (at your option)
#   any later version.
#
#   TThis 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#
# inet2hex - Internet address conversion, dotted-decimal to hex
#
inet2hex ()
{
	local IFS

	IFS=.
	set -- $1

	if (( $# != 4 )); then
		echo "inet2hex: incorrect input format: $1" >&2
		echo "inet2hex: usage: inet2hex XX.XX.XX.XX" >&2
		return 2
	fi
  
	printf "0x%02x%02x%02x%02x\n" $1 $2 $3 $4
}

#
# hex2inet - Internet address conversion, hex to dotted-decimal
#
hex2inet ()
{
	local x1 x2 x3 x4
	local rev

	OPTIND=1
	while getopts "r" o
	do
		case "$o" in
		r)	rev=true;;
		*)	echo "hex2inet: usage: hex2inet [-r] [0x]XXXXXXXX" >&2 ; exit 2;;
		esac
	done
	shift $(( $OPTIND - 1 ))

	case "$1" in
	0x*)	h=${1#??} ;;
	*)	h=$1 ;;
	esac

	if (( ${#h} != 8 )); then
		echo "hex2inet: $h not in inet format" >&2
		echo "hex2inet: usage: hex2inet [0x]XXXXXXXX" >&2
		return 2
	fi

	x1=$(( 0x${h:0:2} ))
	x2=$(( 0x${h:2:2} ))
	x3=$(( 0x${h:4:2} ))
	x4=$(( 0x${h:6:2} ))

	if [ -z "$rev" ] ; then
		printf "%d.%d.%d.%d\n" $x1 $x2 $x3 $x4 
	else
		printf "%d.%d.%d.%d\n" $x4 $x3 $x2 $x1 
	fi
	return 0
}