xref: /netbsd-src/usr.sbin/traceroute/median.awk (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1#!/bin/awk -f
2#
3# Copyright (c) 1990, 1993
4#	The Regents of the University of California.  All rights reserved.
5#
6# This code is derived from software contributed to Berkeley by
7# Van Jacobson.
8#
9# Redistribution and use in source and binary forms, with or without
10# modification, are permitted provided that the following conditions
11# are met:
12# 1. Redistributions of source code must retain the above copyright
13#    notice, this list of conditions and the following disclaimer.
14# 2. Redistributions in binary form must reproduce the above copyright
15#    notice, this list of conditions and the following disclaimer in the
16#    documentation and/or other materials provided with the distribution.
17# 3. All advertising materials mentioning features or use of this software
18#    must display the following acknowledgement:
19#	This product includes software developed by the University of
20#	California, Berkeley and its contributors.
21# 4. Neither the name of the University nor the names of its contributors
22#    may be used to endorse or promote products derived from this software
23#    without specific prior written permission.
24#
25# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35# SUCH DAMAGE.
36#
37#	from: @(#)median.awk	8.1 (Berkeley) 6/6/93
38#	$Id: median.awk,v 1.2 1994/05/16 19:15:59 mycroft Exp $
39#
40/^ *[0-9]/	{
41	# print out the median time to each hop along a route.
42	tottime = 0; n = 0;
43	for (f = 5; f <= NF; ++f) {
44		if ($f == "ms") {
45			++n
46			time[n] = $(f - 1)
47		}
48	}
49	if (n > 0) {
50		# insertion sort the times to find the median
51		for (i = 2; i <= n; ++i) {
52			v = time[i]; j = i - 1;
53			while (time[j] > v) {
54				time[j+1] = time[j];
55				j = j - 1;
56				if (j < 0)
57					break;
58			}
59			time[j+1] = v;
60		}
61		if (n > 1 && (n % 2) == 0)
62			median = (time[n/2] + time[(n/2) + 1]) / 2
63		else
64			median = time[(n+1)/2]
65
66		print $1, median
67	}
68}
69