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Bug #24909 rand function with range always returns low value of range
Submitted: 2003-08-01 14:37 UTC Modified: 2003-08-08 08:36 UTC
Votes:3
Avg. Score:3.3 ± 1.2
Reproduced:3 of 3 (100.0%)
Same Version:2 (66.7%)
Same OS:3 (100.0%)
From: a0 at hush dot com Assigned:
Status: Closed Package: Math related
PHP Version: 4.3.3RC3-dev OS: solaris 8
Private report: No CVE-ID: None
View Developer Edit
 [2003-08-01 14:37 UTC] a0 at hush dot com 
Description:
------------
when using the rand function with php 4.3.2 on solaris 8, it will
return a random value as expected if no range is specified.  if a range
is specified it will always return the low value of the range.

i'm building the module with -DZTS, and it is being loaded into
IWS4.1.

i've modified the code so it works by changing line 36 of
php_rand.h from
#if HAVE_LRAND48
to
#if (HAVE_LRAND48 && !sun)
so PHP_RAND_MAX will get a value of RAND_MAX.

Reproduce code:
---------------
<?
$r = rand();
echo "$r\n";
$r = rand(0, 100);
echo "$r\n";
?>


Expected result:
----------------
24384
0

(it will always return 0)

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 [2003-08-02 12:46 UTC] iliaa@php.net 
I've asked a number of people to replicate the problem, however they were unable to do so using latest PHP and Solaris 8 & 9. Please try the latest snapshot of 4.3.3 and see if the problem persists.
 [2003-08-02 13:55 UTC] a0 at hush dot com 
thanks for the response.

i have downloaded 4.3.3RC2 and tried it.

first, i configured it using no args.  after i compiled
it, the rand() function behaves as expected, even with
a range specified.  this works.

i then configured it with --with-nsapi=/usr/local/iws41,
which is what we need to use the module with our
webserver.  after i compiled it, the cli program now
returns a 0 whenever a range is specified to rand().

i have not really looked through the code, but i would
guess this has something to do with the fact that php
is built with -DZTS in the second scenario (a different
random function is used in rand.c when this is
defined).
 [2003-08-02 15:00 UTC] iliaa@php.net 
I've tried the ZTS version on both Linux & Windows and it worked perfectly in both cases. Did you run test via the nsapi module or using PHP cli or cgi binaries?
 [2003-08-02 15:17 UTC] a0 at hush dot com 
i used the cli binary in both cases
 [2003-08-04 08:39 UTC] sniper@php.net 
Please try this:

# rm config.cache
# ./configure --disable-all --disable-cgi --enable-experimental-zts
# make clean && make
# sapi/cli/php -r 'echo rand(),"\n"; echo rand(0,100),"\n";'
 [2003-08-04 12:18 UTC] a0 at hush dot com 
i configured and built as you specified

Build complete.
(It is safe to ignore warnings about tempnam and tmpnam).

bash-2.05# sapi/cli/php -r 'echo rand(),"\n"; echo rand(0,100),"\n";'
16162
0
bash-2.05# sapi/cli/php -r 'echo rand(),"\n"; echo rand(0,100),"\n";'
31971
0
bash-2.05#
 [2003-08-07 15:48 UTC] thetaphi@php.net 
This Test seems to be related to that:
=======================================================
==============
FAILED TEST SUMMARY
-------------------------------------------------------
--------------
Testing randomization of shuffle() and str_shuffle(). 
[ext/standard/tests/strings/004.phpt]
=======================================================
==============

You get it only in ZTS mode.
 [2003-08-08 08:36 UTC] iliaa@php.net 
This bug has been fixed in CVS.

In case this was a PHP problem, snapshots of the sources are packaged
every three hours; this change will be in the next snapshot. You can
grab the snapshot at http://snaps.php.net/.
 
In case this was a documentation problem, the fix will show up soon at
http://www.php.net/manual/.

In case this was a PHP.net website problem, the change will show
up on the PHP.net site and on the mirror sites in short time.
 
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