Re: [PATCH] Add example to rand.3

[Alejandro Colomar <alx.manpages@xxxxxxxxx>]

Hi,

On 12/28/22 22:25, Jonny Grant wrote:
> That example program looks good, thank you for taking the time to prepare that patch.
> Jonny

Thanks!

This is my v2:

It doesn't recommend libbsd's arc4random().
It also shows that arc4random is just a way to get a random seed, and prints it, 
but then it's as "bad" as any other run of srand(3) + rand(3).

Cheers,

Alex

diff --git a/man3/rand.3 b/man3/rand.3
index 572471749..08ad0a822 100644
--- a/man3/rand.3
+++ b/man3/rand.3
@@ -190,6 +190,9 @@ .SH EXAMPLES
 pseudo-random sequence produced by
 .BR rand ()
 when given a particular seed.
+When the seed is
+.IR \-1 ,
+the program uses a random seed.
 .PP
 .in +4n
 .\" SRC BEGIN (rand.c)
@@ -211,7 +214,13 @@ .SH EXAMPLES
     seed = atoi(argv[1]);
     nloops = atoi(argv[2]);

+    if (seed == -1) {
+        seed = arc4random();
+        printf("seed: %u\en", seed);
+    }
+
     srand(seed);
+
     for (unsigned int j = 0; j < nloops; j++) {
         r =  rand();
         printf("%d\en", r);


--
<http://www.alejandro-colomar.es/>

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