[Bug 804355] Re: jot random number generator broken in batch jobs

[Launchpad Bug Tracker]

This bug was fixed in the package athena-jot - 9.0-5ubuntu1

---------------
athena-jot (9.0-5ubuntu1) precise; urgency=low

  * Use arc4random number generation instead of time based (LP: #804355).
    - d/control: Add Build-Depends - libbsd-dev, dh-autoreconf.
    - d/rules: Updated to call dh_autoreconf.
 -- Alexey Ivanov <rbtz at yandex-team.ru>   Mon, 26 Mar 2012 15:10:40 +0100

** Changed in: athena-jot (Ubuntu)
       Status: New => Fix Released

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https://bugs.launchpad.net/bugs/804355

Title:
  jot random number generator broken in batch jobs

Status in “athena-jot” package in Ubuntu:
  Fix Released

Bug description:
  jot -r generates same random numbers within one second time so it's
  unusable in batch jobs like shell scripts.

  There is code for initializing "random" seed:
      s = (randomize ? time(0) : STEP_DEF);
      /*... snip ....*/
      srand((int) s);

  Here is an example of this behavior:
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455778
  9981995
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455779
  2355993
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455779
  2355993
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455779
  2355993
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455780
  3745306
  rbtz at rbtz-desktop:~$ date +%s; jot -r 1 0 10000000
  1309455780
  3745306

  As fast fix pid can be added to seed
  srandom((int) s ^ (getpid()<<4));

  As good fix arc4random or similar mechanism can be used.

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