>Number:         476
>Category:       lib
>Synopsis:       rand48 manual page inconsistent with operation of lrand48 and mrand48
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    gnats-admin (Library Bug People)
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Sep 14 10:05:07 1994
>Originator:     Douglas Crosher
>Organization:
	Swinburne University of technology
>Release:        
>Environment:

System: NetBSD 1.0_BETA : Wed Aug 10 1994

>Description:

>How-To-Repeat:

Read the manual page for rand48, eg. man rand48

Note: 	
     lrand48() and nrand48() return values of type long in the range [-2**31,
     2**31-1]. The high-order (32) bits of r(n+1) are loaded into the returned
     value.

     mrand48() and jrand48() return values of type long in the range [0,
     2**31-1]. The high-order (31) bits of r(n+1) are loaded into the lower
     bits of the returned value, with the topmost (sign) bit set to zero.


Now run the following program:
-=-=-=-
#include <stdlib.h>
#include <stdio.h>

main(){
srand48(123456);

for (;;)
printf("%9x, %9x \n",lrand48(), mrand48());

}
-=-=-=-
Output:
 55caefe0,  f0ce381c 
 1a764ab1,  a1b9c755 
 24eb7a12,   e2d12e1 
 7eb5b0ce,  38e1ce13 
 7b4010d4,  8bd86ab5 
 305f1e5b,  45cdafd0 
  3be407c,  67653957 
 280d5386,   f80c314 
 15d75ba1,  a8c6de47 

Note that lrand48 returns a 31 bit number and mrand48 returns a 32 bit
number, this is consistent with other machines I have tried but
inconsistent with the manual page which describes the opposite
behavior.

>Fix:

Swap the definitions of lrand48 and mrand48 in the manual page
lib/stdlib/rand48.3
>Audit-Trail:
>Unformatted: