question on rand()

Dennis Clarke
Sat Aug 6 22:45:00 GMT 2011

> Anna Sidera <> writes:
>>>From this, can I find out when the numbers start repeating? How can I
>>> find it? I cannot find the period using
>> man rand
> This question really doesn't have anything to do with gcc.  gcc does not
> provide a rand function.  The rand function will come from your C
> library, and gcc does not include a C library.
> If you are using GNU glibc, which is probably the case if you are using
> a GNU/Linux system, then rand is not implemented as a linear
> congruential generator, and the period is quite long.  See the source
> code.

At risk of being well and truely off topic, I suggest that prng folks look
at the "Mersenne twister" algorithm developed by Makoto Matsumoto and
Takuji Nishimura :

Works great.

I think that ends this topic.

| Dennis Clarke           | Solaris and Linux and Open Source |
|   | are my passion. ( FREE == OPEN )  |

More information about the Gcc-help mailing list