rand(3C)																  rand(3C)

NAME

       rand(), rand_r(), srand() - simple random-number generator

SYNOPSIS

DESCRIPTION

       uses  a	multiplicative,  congruential, random-number generator with period 2^32 that returns successive pseudo-random numbers in the range
       from 0 to 2^15-1.

       can be called at any time to reset the random-number generator to a random starting point.  The generator is initially seeded with a  value
       of 1.

       returns a random number at the address pointed to by the randval parameter.  The seed parameter can be set at any time to start the random-
       number generator at an arbitrary point.

   Note
       The spectral properties of leave a great deal to be desired.  provides a much better, though more elaborate, random-number  generator  (see
       drand48(3C)).

RETURN VALUE

       If seed or randval is NULL, returns 0.  Otherwise, returns a psuedo-random integer.

EXAMPLES

       The following:

	      int x, y;
	      srand(10);
	      x = rand();
	      y = rand();

       would produce the same results as:

	      int x, y, s = 10;
	      x=rand_r(&s);
	      y=rand_r(&s);

WARNINGS

       Users  of  should  note	that  rand_r()	now conforms with POSIX.1c.  The old prototype of is supported for compatibility with existing DCE
       applications only.

SEE ALSO

       drand48(3C), random(3M), thread_safety(5), random(7).

STANDARDS CONFORMANCE

																	  rand(3C)