examples/var_service/dhcp_if/convert2ipconf

#!/bin/sh
# convert:

# dhcptype=5
# serverid=172.16.42.102
# lease=97200
# interface=eth0
# ip=172.16.42.177
# subnet=255.255.255.0
# mask=24
# broadcast=172.16.22.255
# router=172.16.42.98
# dns=10.34.32.125 10.32.63.5 10.34.255.7 10.11.255.27
# domain=lab.example.com example.com
# ntpsrv=10.34.32.125 10.34.255.7

# into:

#let cfg=cfg+1
#if[$cfg]=...; ip[$cfg]=...; ipmask[$cfg]=.../...; gw[$cfg]=...; net[$cfg]=... dns[$cfg]=...

exec >"$0.out" 2>&1

test "$interface" || exit 1
test -f "$1" || exit 1

# Unsafe, and does not handle values with spaces:
#. "./$1" || exit 1
# Safe(r) parsing:
sq="'"
while read line; do
	#echo "line: $line"
	# Skip empty lines and lines with single quotes
	test "${line##*$sq*}" || continue
	var="${line%%=*}"
	val="${line#*=}"
	#echo "var:$var val:'$val'"
	eval "$var='$val'"
done <"$1"

{
echo "let cfg=cfg+1"
test "$interface" 	&& echo "if[\$cfg]='$interface'"
test "$ip"		&& echo "ip[\$cfg]='$ip'"
test "$ip" && test "$mask" \
			&& echo "ipmask[\$cfg]='$ip/$mask'"
test "$router"		&& echo "gw[\$cfg]='$router'"
test "$dns"		&& echo "dns[\$cfg]='$dns'"
# TODO: I never saw a dhcp server which correctly announces
# which subnet(s) is/are available thru advertised router
# Assume 0/0
echo "net[\$cfg]='0/0'"
} >"$2"