rand, srand - bad random number generator
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
The srand() function sets its argument as the seed for a new
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 functions are automatically seeded with
a value of 1.
The rand_r() is a thread-safe version of rand(). Storage
for the seed
must be provided through the seed argument, and needs to
have been initialized
by the caller.
arc4random(3), rand48(3), random(3)
The rand() and srand() functions conform to ANSI X3.159-1989
The rand_r() function conforms to ISO/IEC 9945-1 ANSI/IEEE
Std 1003.1c Draft 10.
OpenBSD 3.6 June 29, 1991
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