From: Myknees AT aol DOT com
Message-ID: <b8ad4e96.34d4e87b@aol.com>
Date: Sun, 1 Feb 1998 16:26:16 EST
To: eliz AT is DOT elta DOT co DOT il
Cc: dj AT delorie DOT com, djgpp AT delorie DOT com
Mime-Version: 1.0
Subject: Re: Documentation [was Re: Random implementation]
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In a message dated 98-02-01 14:05:42 EST, eliz AT is DOT elta DOT co DOT il writes:
>  On Sun, 1 Feb 1998 Myknees AT aol DOT com wrote:
>  
>  > How would it be if I include this
>  > fact in the diffs, stating that seeding the function is necessary in the 
> two
>  > cases mentioned above.  That seems like it would be helpful.
>  
>  Seems like a good idea.  Please go ahead.

Everything below the equals line is output from diff.

--Ed (Myknees)


=========================================
*** rand.txh	Mon Jul 10 01:39:56 1995
--- rand3.txh	Sun Feb  1 16:15:10 1998
***************
*** 1,24 ****
  @node rand, random number
! @subheading Syntax
  
  @example
  #include <stdlib.h>
  
  int rand(void);
  @end example
  
  @subheading Description
  
  Returns a pseudo-random number from zero to @code{RAND_MAX}. 
  
  @subheading Return Value
  
! The number.
  
  @subheading Example
  
  @example
  /* random pause */
  for (i=rand(); i; i--);
  @end example
  
--- 1,48 ----
  @node rand, random number
! n AT subheading Syntax
  
  @example
  #include <stdlib.h>
  
  int rand(void);
+ void srand(unsigned _seed);
  @end example
  
  @subheading Description
  
  Returns a pseudo-random number from zero to @code{RAND_MAX}. 
  
+ This function has its own default seed but may also be seeded with the
+ function @code{srand} (found in the @code{rand} source file).  It is
+ only necessary to use @code{srand} in the following cases:
+ 
+ @itemize @bullet
+ 
+ @item
+ 
+ If the pseudo-random sequence must be different each time you run the
+ program
+ 
+ @item
+ 
+ If the sequence must continue from the same place it ended on some
+ previous run
+ 
+ @end itemize
+ 
  @subheading Return Value
  
! The pseudo-random number.
  
  @subheading Example
  
  @example
  /* random pause */
  for (i=rand(); i; i--);
+ @end example
+ 
+ @example
+ /* seed @code{rand} with current time */
+ srand(time(0));
  @end example