drand48()

Updated: May 06, 2022

Generate a pseudo-random double

Synopsis:

#include <stdlib.h>

double drand48( void );

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The drand48() function uses a linear congruential algorithm and 48-bit integer arithmetic to generate a nonnegative double uniformly distributed over the interval [0.0, 1.0).

Call one of lcong48(), seed48(), or srand48() to initialize the random-number generator before calling drand48(), lrand48(), or mrand48().

The erand48() function is a thread-safe version of drand48().

Returns:

A pseudo-random double.

Classification:

POSIX 1003.1 XSI

Safety:  
Cancellation point No
Interrupt handler No
Signal handler No
Thread No