contrib/traceroute/median.awk

   1 /^ *[0-9]/      {
   2         # print out the median time to each hop along a route.
   3         tottime = 0; n = 0;
   4         for (f = 5; f <= NF; ++f) {
   5                 if ($f == "ms") {
   6                         ++n
   7                         time[n] = $(f - 1)
   8                 }
   9         }
  10         if (n > 0) {
  11                 # insertion sort the times to find the median
  12                 for (i = 2; i <= n; ++i) {
  13                         v = time[i]; j = i - 1;
  14                         while (time[j] > v) {
  15                                 time[j+1] = time[j];
  16                                 j = j - 1;
  17                                 if (j < 0)
  18                                         break;
  19                         }
  20                         time[j+1] = v;
  21                 }
  22                 if (n > 1 && (n % 2) == 0)
  23                         median = (time[n/2] + time[(n/2) + 1]) / 2
  24                 else
  25                         median = time[(n+1)/2]
  26
  27                 print $1, median
  28         }
  29 }