Generates pseudo-random numbers.
Thread-Safe C Library (libc_r.a)
Berkeley Compatibility Library (libbsd.a)
#include <stdlib.h>
int rand_r (Seed) unsigned int *Seed;
The rand_r subroutine generates and returns a pseudo-random number using a multiplicative congruential algorithm. The random-number generator has a period of 2**32, and it returns successive pseudo-random numbers.
Note: The rand_r subroutine is a simple random-number generator. Its spectral properties (the mathematical measurement of the randomness of a number sequence) are limited. See the drand48 subroutine or the random subroutine for more elaborate random-number generators that have greater spectral properties.
| Seed | Specifies an initial seed value. |
| 0 | Indicates that the subroutines was successful. |
| -1 | Indicates that the subroutines was not successful. |
If the following condition occurs, the rand_r subroutine sets the errno global variable to the corresponding value.
| EINVAL | The Seed parameter specifies a null value. |
These subroutines are part of Base Operating System (BOS) Runtime.
Programs using this subroutine must link to the libpthreads.a library.
| /usr/include/sys/types.h | Defines system macros, data types, and subroutines. |
The drand48, erand48_r, lrand48_r, nrand48_r, mrand48_r, jrand48_r, srand48_r, seed48_r, or lcong48_r subroutine, random, srandom_r, initstate_r, or setstate_r subroutine.
Subroutines Overview and List of Multithread Subroutines in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.