Manpages - drand48_r.3

drand48_r, erand48_r, lrand48_r, nrand48_r, mrand48_r, jrand48_r, srand48_r, seed48_r, lcong48_r - generate uniformly distributed pseudo-random numbers reentrantly

  #include <stdlib.h>

  int drand48_r(struct drand48_data *restrict buffer,
   double *restrict result);
  int erand48_r(unsigned short xsubi[3],
   struct drand48_data *restrict buffer,
   double *restrict result);

  int lrand48_r(struct drand48_data *restrict buffer,
   long *restrict result);
  int nrand48_r(unsigned short xsubi[3],
   struct drand48_data *restrict buffer,
   long *restrict result);

  int mrand48_r(struct drand48_data *restrict buffer,
   long *restrict result);
  int jrand48_r(unsigned short xsubi[3],
   struct drand48_data *restrict buffer,
   long *restrict result);

  int srand48_r(long int seedval, struct drand48_data *buffer);
  int seed48_r(unsigned short seed16v[3], struct drand48_data *buffer);
  int lcong48_r(unsigned short param[7], struct drand48_data *buffer);

Feature Test Macro Requirements for glibc (see *feature_test_macros*(7)):

All functions shown above:

      /* Glibc since 2.19: */ _DEFAULT_SOURCE
          || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

These functions are the reentrant analogs of the functions described in *drand48*(3). Instead of modifying the global random generator state, they use the supplied data buffer.

Before the first use, this struct must be initialized, for example, by filling it with zeros, or by calling one of the functions *srand48_r*(), *seed48_r*(), or *lcong48_r*().

The return value is 0.

For an explanation of the terms used in this section, see *attributes*(7).

These functions are GNU extensions and are not portable.

*drand48*(3), *rand*(3), *random*(3)

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