ID: 27052 Updated by: [EMAIL PROTECTED] Reported By: webmaster at armondc dot com -Status: Open +Status: Bogus Bug Type: Math related Operating System: Windows 2000 Professional PHP Version: 4.3.5RC2-dev New Comment:
RTFM: Note: On some platforms (such as Windows) RAND_MAX is only 32768. If you require a range larger than 32768, consider using mt_rand() instead. Previous Comments: ------------------------------------------------------------------------ [2004-01-26 20:03:17] webmaster at armondc dot com I tried it on 4.3.5RC2-dev, and it's still relativly the same. The pattern is slightly different, but is still as predictable as before. ------------------------------------------------------------------------ [2004-01-26 19:04:34] [EMAIL PROTECTED] Please try using this CVS snapshot: http://snaps.php.net/php4-STABLE-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-STABLE-latest.zip Some rand() related bugs have already been fixed.. ------------------------------------------------------------------------ [2004-01-26 15:56:22] webmaster at armondc dot com On the "actual result" its not as easily spotted without wrapping. This should give a better picture: ]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F [LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\ ------------------------------------------------------------------------ [2004-01-26 15:53:26] webmaster at armondc dot com Description: ------------ I'm not sure if this is a very major problem, or even a bug, but here goes: It seems rand() on Windows is very predictable. I've tried it on 2 Windows Systems, and they were both predictable. It showed a breif unpredictable segment, then followed by the same string of characters over and over, and finally a few more unpredictable characters. I tried this on a FreeBSD 5.2 System, and it was unpreditable enough. Seems to be a windows-only problem. I also noticed bug#11108 - It seems similar, but the submitter was using his own seeds, and I am using without. Reproduce code: --------------- <?php // This will reproduce the problem // on windows for($x = 0; $x < 500; $x++) { echo chr((rand()%32)+65); } // This is a quick-fix, but // goes agaist the documentation's // 'no need for srand()' for($x = 0; $x < 500; $x++) { srand(hexdec(substr(md5(microtime()), 0, 8))); echo chr((rand()%32)+65); } ?> Expected result: ---------------- Something a bit random like: HEOSITFS[ZYH_EVIVVXSLCWRHHC_]_L^PIBTC\TXPBWQLCM^VZSU`UHOG[\VF[KCDGFZM^Q\IG^KAIYPIYBSBIMGHXIBMPHLY\OAZMYAZPJ_`D`F\X\QXR[GP]DQLRHMYIOERBMEKBDJMJPN]J\\KPES^EGRKKO^S[`XL\SSHQXOYQU_JDMM`ZEUEOQOYMHJPYDTRRU_URHYJGXRQYDYADD]OBVUGC^GGSXPRJJAOAKRAYYN^Q\`XFQJNOWQKAJBFONFXNDZFFIMYRL`ROH^]IM_MINJI\MJJAVG`]_B_EAV`C\O_\DHCHLX_NIO`U^KMJF\`K]VZDOZ_FAWCZC_IQK^[NTPZCC]XEFZ[`\AG[PV^XLPRYVAS]ZPH`^WAXYAZYGK_M_QK`F]PRMP^BBPTRV^KV_VDOLFIM]WQNHVF^DYWGGSGLJ_ZMODG[Z_AAXBYD^FS\MITLZESC`DXLH]NWNIVWZZMVMSXFQMG[O[W[YSPVMTQLHD Actual result: -------------- An easily spotted pattern: ]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\YRWXENCTQJOP]F[LIBGHU^SDAZ_`MVK\ ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=27052&edit=1
