traceroute.tproj/median.awk

   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 #       @(#)median.awk  8.1 (Berkeley) 6/6/93
  38 #
  39 /^ *[0-9]/      {
  40         # print out the median time to each hop along a route.
  41         tottime = 0; n = 0;
  42         for (f = 5; f <= NF; ++f) {
  43                 if ($f == "ms") {
  44                         ++n
  45                         time[n] = $(f - 1)
  46                 }
  47         }
  48         if (n > 0) {
  49                 # insertion sort the times to find the median
  50                 for (i = 2; i <= n; ++i) {
  51                         v = time[i]; j = i - 1;
  52                         while (time[j] > v) {
  53                                 time[j+1] = time[j];
  54                                 j = j - 1;
  55                                 if (j < 0)
  56                                         break;
  57                         }
  58                         time[j+1] = v;
  59                 }
  60                 if (n > 1 && (n % 2) == 0)
  61                         median = (time[n/2] + time[(n/2) + 1]) / 2
  62                 else
  63                         median = time[(n+1)/2]
  64
  65                 print $1, median
  66         }
  67 }