RAND(3) Library Functions Manual RAND(3)
rand, srand, rand_r -- bad random number generator
Standard C Library (libc, -lc)
srand(unsigned int seed);
rand_r(unsigned int *seed);
These interfaces are obsoleted by random(3).
The rand() function computes a sequence of pseudo-random integers in the
range of 0 to RAND_MAX (as defined by the header file <stdlib.h>).
The srand() function sets its argument as the seed for a new sequence of
pseudo-random numbers to be returned by rand(). These sequences are
repeatable by calling srand() with the same seed value.
If no seed value is provided, the rand() function is automatically seeded
with a value of 1.
The rand_r() function is a reentrant interface to rand(); the seed has to
be supplied and is maintained by the caller.
The rand() and srand() functions conform to ANSI X3.159-1989
(``ANSI C89''). The rand_r() function conforms to IEEE Std 1003.1c-1995
NetBSD 6.1.5 June 4, 1993 NetBSD 6.1.5