Ask for opinion: changing rand(3) to random(3) in awk(1)

[Chenguang Li]

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Lowell Gilbert <freebsd-questions-local at be-well.ilk.org> wrote：

I had thought about that a few years ago, but I didn't have any cases
where it mattered. Note that your example (footnote 1) is *not* such a
case. The bug in that case is calling srand() multiple times, rather
than just once at the beginning. 

You could take a patch to the security or hackers list, but first you
should figure out what problem you are trying to solve. 

Oops, I think you're right, I just gave the post a glance, should have read it through and described my issue as "the same symptom".

The problem I was trying to describe was its "one-shot" randomness, take these two as examples (where it matters):

1. You wrote a script[1] that simulate rolling a dice, it would produce the same result if executed within, say, 5 seconds.
2. You have a CGI script which will show different content based on the number generated by rand().

In the first situation, you can generate all the outcomes in a single run by using for-loop, but the first outcome will be the same. OSX's awk(1) will produce a reasonable number every time I run it. In the latter one, you could call rand() once and throw away the result, and call it again to get another number. Both are practical workarounds, but we do have a better choice: applying the modification I suggested before.

If others are not affected by the problem I described above, then I am okay with that. The other reason why I suggest this is, I see no loss, only to make it better.

[1] BEGIN { srand(); print int(1+rand()*6); } or BEGIN { srand(); } { print int(1+rand()*6); }, won't matter.

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Chenguang Li

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