rand(3ucb) [opensolaris man page]

rand(3UCB)					     SunOS/BSD Compatibility Library Functions						rand(3UCB)

NAME

       rand, srand - simple random number generator

SYNOPSIS

       /usr/ucb/cc [ flag ... ] file ...

       int rand();

       int srand(seed)
       unsigned seed;

DESCRIPTION

       rand()  uses a multiplicative congruential random number generator with period 2^32 to return successive pseudo-random numbers in the range
       from 0 to 2^31 -1.

       srand() 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.

SEE ALSO

       cc(1B), drand48(3C), rand(3C), random(3C)

NOTES

       Use of these interfaces should be restricted to only applications written on BSD platforms.  Use of these interfaces with any of the system
       libraries or in multi-thread applications is unsupported.

       The spectral properties of rand() leave a great deal to be desired. drand48(3C) and random(3C) provide much better, though more	elaborate,
       random-number generators.

       The low bits of the numbers generated are not very random; use the middle bits. In particular the lowest bit alternates between 0 and 1.

SunOS 5.11							    30 Oct 2007 							rand(3UCB)

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)