wagon/back/lib/ns_lookup_rdns

#!/bin/bash
# FILE:       	wgapi:back/lib/ns_lookup_rdns
# DESCRIPTION:	Get a domain from an IP address
# USAGE:      	rdns ip
# OUTPUT:     	The domain for that IP
# ERRORS:
# 	3: bad usage
# 	4: not found
# 	5: server down
# 	6: nslookup not found
# 	7: config not found

# Accept exactly one argument
[ ${#} -eq 1 ] || exit 3
CONFIG_FILE='/etc/wgapi/config'
[ -f "${CONFIG_FILE}" ] || exit 7
source "${CONFIG_FILE}"

domain="$("${LIB_DIR}/ns_lookup_send" "${1}")"
case $? in
	0) printf '%s' "${domain%.}" | cut -d'=' -f2 | xargs -0; exit 0;;
	4) printf 'Domain for %s not found!\n' "${1}" >&2; exit 4;;
	5) printf 'Nameserver not available: %s\n' "${DNS_MASTER}" >&2; exit 5;;
	6) printf 'nslookup not installed!\n' >&2; exit 6;;
	*) printf 'Bad usage: %s %s\n' "${0}" "${@}" >&2; exit 3;;
esac