drand48,  erand48, lrand48, nrand48, mrand48, jrand48, srand48, seed48,
   lcong48 - generate uniformly distributed pseudo-random numbers


   #include <stdlib.h>

   double drand48(void);

   double erand48(unsigned short xsubi[3]);

   long int lrand48(void);

   long int nrand48(unsigned short xsubi[3]);

   long int mrand48(void);

   long int jrand48(unsigned short xsubi[3]);

   void srand48(long int seedval);

   unsigned short *seed48(unsigned short seed16v[3]);

   void lcong48(unsigned short param[7]);

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

   All functions shown above: _XOPEN_SOURCE
       || /* Glibc since 2.19: */ _DEFAULT_SOURCE
       || /* Glibc versions <= 2.19: */ _SVID_SOURCE


   These  functions  generate  pseudo-random  numbers  using  the   linear
   congruential algorithm and 48-bit integer arithmetic.

   The  drand48()  and  erand48()  functions  return  nonnegative  double-
   precision floating-point values uniformly distributed over the interval
   [0.0, 1.0).

   The  lrand48() and nrand48() functions return nonnegative long integers
   uniformly distributed over the interval [0, 2^31).

   The mrand48() and  jrand48()  functions  return  signed  long  integers
   uniformly distributed over the interval [-2^31, 2^31).

   The  srand48(),  seed48()  and  lcong48()  functions are initialization
   functions, one of  which  should  be  called  before  using  drand48(),
   lrand48()   or  mrand48().   The  functions  erand48(),  nrand48()  and
   jrand48() do not require an initialization function to be called first.

   All the functions work by generating a sequence of 48-bit integers, Xi,
   according to the linear congruential formula:

          Xn+1 = (aXn + c) mod m, where n >= 0

   The  parameter  m = 2^48, hence 48-bit integer arithmetic is performed.
   Unless lcong48() is called, a and c are given by:

          a = 0x5DEECE66D
          c = 0xB

   The value returned  by  any  of  the  functions  drand48(),  erand48(),
   lrand48(),  nrand48(),  mrand48()  or  jrand48()  is  computed by first
   generating the next 48-bit Xi in the sequence.   Then  the  appropriate
   number  of  bits, according to the type of data item to be returned, is
   copied from the high-order bits of Xi and transformed into the returned

   The  functions drand48(), lrand48() and mrand48() store the last 48-bit
   Xi generated in an internal buffer.  The functions erand48(), nrand48()
   and  jrand48()  require  the calling program to provide storage for the
   successive Xi values in the array argument xsubi.   The  functions  are
   initialized  by  placing  the initial value of Xi into the array before
   calling the function for the first time.

   The initializer function srand48() sets the high order 32-bits of Xi to
   the  argument  seedval.  The low order 16-bits are set to the arbitrary
   value 0x330E.

   The initializer function seed48() sets the value of Xi  to  the  48-bit
   value  specified  in the array argument seed16v.  The previous value of
   Xi is copied into an internal buffer and a pointer to  this  buffer  is
   returned by seed48().

   The  initialization  function  lcong48()  allows  the  user  to specify
   initial values for Xi, a and c.   Array  argument  elements  param[0-2]
   specify  Xi,  param[3-5]  specify  a,  and param[6] specifies c.  After
   lcong48() has been called, a subsequent call  to  either  srand48()  or
   seed48() will restore the standard values of a and c.


   For   an   explanation   of   the  terms  used  in  this  section,  see

   │InterfaceAttributeValue                  │
   │drand48(), erand48(), │ Thread safety │ MT-Unsafe race:drand48 │
   │lrand48(), nrand48(), │               │                        │
   │mrand48(), jrand48(), │               │                        │
   │srand48(), seed48(),  │               │                        │
   │lcong48()             │               │                        │
   The above functions record global  state  information  for  the  random
   number generator, so they are not thread-safe.


   POSIX.1-2001, POSIX.1-2008, SVr4.


   rand(3), random(3)


   This  page  is  part of release 4.09 of the Linux man-pages project.  A
   description of the project, information about reporting bugs,  and  the
   latest     version     of     this    page,    can    be    found    at

                              2016-03-15                        DRAND48(3)

More Linux Commands

XDrawPoint(3) - draw points and points structure (Man Page)
The XDrawPoint function uses the foreground pixel and function components of the GC to draw a single point into the specified drawable; XDrawPoints draws multip

nlmconv(1) - converts object code into an NLM. (Man Page)...
nlmconv converts the relocatable i386 object file infile into the NetWare Loadable Module outfile, optionally reading headerfile for NLM header information. For

getrpcbynumber_r(3) - get RPC entry (reentrant) (Man Page)
The getrpcent_r(), getrpcbyname_r(), and getrpcbynumber_r() functions are the reentrant equivalents of, respectively, getrpcent(3), getrpcbyname(3), and getrpcb

systemd-timedated(8) Time and date bus mechanism (Man Page)
systemd-timedated is a system service that may be used as a mechanism to change the system clock and timezone, as well as to enable/disable NTP time synchroniza

autotrace(1) converts bitmap image data into vector graphics
The autotrace program accepts bitmap graphics from the file inputfile specified on the command line, and as output produces a collection of splines approximatin

XGetModifierMapping(3) - manipulate keyboard encoding and ke
The XChangeKeyboardMapping function defines the symbols for the specified number of KeyCodes starting with first_keycode. The symbols for KeyCodes outside this

Tcl_CreateEncoding(3) - procedures for creating and using en
Tcl_GetEncoding finds an encoding given its name. The name may refer to a built-in Tcl encoding, a user-defined encoding registered by calling Tcl_CreateEncodin

ppmtoppm(1) - copy PPM image (Commands - Linux man page)....
This program is part of Netpbm(1) ppmtoppm simply copies a PPM image from Standard Input to Standard Output. This may seem an unnecessary duplication of cat, bu

btrfs-balance(8) balance btrfs filesystem - Linux man page
btrfs balance is used to balance chunks in a btrfs filesystem across multiple or even single device. See btrfs-device(8) for more details about the effect on de

Tcl_SignalId(3) - Convert signal codes - Linux manual page
Tcl_SignalId and Tcl_SignalMsg return a string representation of the provided signal number (sig). Tcl_SignalId returns a machine-readable textual identifier su

ldap_value_free(3) - LDAP attribute value handling routines
These routines are used to retrieve and manipulate attribute values from an LDAP entry as returned by ldap_first_entry(3) or ldap_next_entry(3). ldap_get_values

DMXGetDesktopAttributes(3) - determine global bounding box
DMXGetDesktopAttributes() returns information about the desktop in DMXDesktopAttributes: typedef struct { unsigned int width; unsigned int height; int shiftX; i

We can't live, work or learn in freedom unless the software we use is free.