1DRAND48_R(3)               Linux Programmer's Manual              DRAND48_R(3)
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NAME

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

11       #include <stdlib.h>
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13       int drand48_r(struct drand48_data *restrict buffer,
14                     double *restrict result);
15       int erand48_r(unsigned short xsubi[3],
16                     struct drand48_data *restrict buffer,
17                     double *restrict result);
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19       int lrand48_r(struct drand48_data *restrict buffer,
20                     long *restrict result);
21       int nrand48_r(unsigned short xsubi[3],
22                     struct drand48_data *restrict buffer,
23                     long *restrict result);
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25       int mrand48_r(struct drand48_data *restrict buffer,
26                     long *restrict result);
27       int jrand48_r(unsigned short xsubi[3],
28                     struct drand48_data *restrict buffer,
29                     long *restrict result);
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31       int srand48_r(long int seedval, struct drand48_data *buffer);
32       int seed48_r(unsigned short seed16v[3], struct drand48_data *buffer);
33       int lcong48_r(unsigned short param[7], struct drand48_data *buffer);
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35   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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37       All functions shown above:
38           /* Glibc since 2.19: */ _DEFAULT_SOURCE
39               || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
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DESCRIPTION

42       These functions are the reentrant analogs of the functions described in
43       drand48(3).  Instead of modifying the global  random  generator  state,
44       they use the supplied data buffer.
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46       Before  the first use, this struct must be initialized, for example, by
47       filling it with zeros, or by calling one of the functions  srand48_r(),
48       seed48_r(), or lcong48_r().
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RETURN VALUE

51       The return value is 0.
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ATTRIBUTES

54       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
55       tributes(7).
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57       ┌────────────────────────────────┬───────────────┬─────────────────────┐
58       │Interface                       │ Attribute     │ Value               │
59       ├────────────────────────────────┼───────────────┼─────────────────────┤
60       │drand48_r(), erand48_r(),       │ Thread safety │ MT-Safe race:buffer │
61       │lrand48_r(), nrand48_r(),       │               │                     │
62       │mrand48_r(), jrand48_r(),       │               │                     │
63       │srand48_r(), seed48_r(),        │               │                     │
64       │lcong48_r()                     │               │                     │
65       └────────────────────────────────┴───────────────┴─────────────────────┘
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CONFORMING TO

68       These functions are GNU extensions and are not portable.
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SEE ALSO

71       drand48(3), rand(3), random(3)
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COLOPHON

74       This page is part of release 5.13 of the Linux  man-pages  project.   A
75       description  of  the project, information about reporting bugs, and the
76       latest    version    of    this    page,    can     be     found     at
77       https://www.kernel.org/doc/man-pages/.
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81GNU                               2021-03-22                      DRAND48_R(3)
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