#!/usr/bin/awk -f
#

#
# ipsort [<fieldnum>|-]
#
#	Sort the input by the IP-number in the <fieldnum>-th field
#	or remove the temporarily added ip-sort-field from the input.
#

BEGIN {
	STDERR = "/dev/stderr";
	ipfield = ARGV[1];  ARGV[1] = "";

	if (ipfield == "-")
		remove = 1;
	else if (ipfield+0 <= 0) {
		printf ("ipsort: no or zero ip-number field\n") >STDERR;
		exit(1);
		}
	}

// {
	if (remove == 1) {
		sub(/^[^ ]+ /, "", $0);
		print $0;
		}
	else if (split($ipfield, x, ".") == 4) {
		str = sprintf("%03d.%03d.%03d.%03d", x[1], x[2], x[3], x[4]);
		print str, $0 | "sort";
		}
	}