From: Operating system: Windows Server 2008 PHP version: 5.3.10 Package: PCRE related Bug Type: Bug Bug description:Unexplained bool(false) returned from preg_match
Description: ------------ PHP VC9 x86 Thread Safe (from http://windows.php.net/download/) Using a regex to validate if a string is a valid hostname (host or FQDN). It seems that for certain length strings trying to match a literal period at the end will cause the preg_match to return false if the string does not have a period in it. It also will return false if the string has a period at the end, and the regex does not try to match them. The regex is using subpatterns ()to apply the zero or more repetition quantifier *. I tried with both capturing and non-capturing (?:), both yield the same result. However, if I use the one or more quantifier + it does not return bool(false). Using {0,} instead of * does not change the outcome. It seems that the cutoff length for the string is about 20 characters. Less than that, the results are int(0) or int(1) depending on if the regex matches, longer than that, and bool(false) is returned. If the subpattern is part of a longer string, it does work as anticipated. Matching a literal period at the beginning of the pattern does not yield an error. Substituting a-zA-Z0-9 for the [:alnum:] character class does not affect the results. error_get_last() does not return anything, nothing is showing up in logs with error_reporting(-1) set either. Test script: --------------- $regexs = array ( '/^[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*$/', '/^(?:[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*\.)*$/', '/^(?:[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*\.)+$/', '/^(?:[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*\.)*[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*$/' ); $hosts = array ( 'ABCDEFGHIJ1234567890.', // long string with period at end 'ABCDEFGHI234567890.', // slightly shorter string with period at end 'ABCDEFGHIJ1234567890', // long string no period 'ABCDEFGHI1234567890', // a little shorter 'ABCDEFGHI123456789', // even shorter 'ABCDEFGHIJ-1234567890', // long with hyphen 'ABCDEFGHIJ-123456789', // sorter with hyphen 'ABCDEFGHI-123456789', // even shorter with hyphen 'WWW.ABCDEFGHIJ-1234567890.COM', // a FQDN with long sting and hyphen 'WWW.SUB-SUBDOMAIN.SUBDOMAIN.ABCD-EFGH-IJKL-MNOP-QRST-UVWX-YZ-12345-67890-abcd-efgh-hijk.COM' // a really long FQDN ); foreach ($regexs as $regex) { echo "\nRegex: $regex\n"; foreach ($hosts as $host) { echo " Host: $host\n"; $result = preg_match($regex, $host); echo ' Result: '; if ($result === false) { echo '(error) '; print_r(error_get_last()); // never prints anything? } else { echo ($result) ? '(match) ' : '(no match) '; } var_dump($result); } } Expected result: ---------------- none of the results should yield bool(false) Actual result: -------------- // just the output from the last regex, but others yield bool(false) Regex: /^(?:[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*\.)*[[:alnum:]](?:[[:alnum:]\-]*[[:alnum:]])*$/ Host: ABCDEFGHIJ1234567890. Result: (error) bool(false) Host: ABCDEFGHI234567890. Result: (error) bool(false) Host: .ABCDEFGHIJ1234567890 Result: (no match) int(0) Host: ABCDEFGHIJ1234567890 Result: (error) bool(false) Host: ABCDEFGHI1234567890 Result: (error) bool(false) Host: ABCDEFGHI123456789 Result: (match) int(1) Host: ABCDEFGHIJ-1234567890 Result: (error) bool(false) Host: ABCDEFGHIJ-123456789 Result: (error) bool(false) Host: ABCDEFGHI-123456789 Result: (match) int(1) Host: WWW.ABCDEFGHIJ-1234567890.COM Result: (match) int(1) Host: WWW.SUB-SUBDOMAIN.SUBDOMAIN.ABCD-EFGH-IJKL-MNOP-QRST-UVWX-YZ-12345-67890-abcd-efgh-hijk.COM Result: (match) int(1) -- Edit bug report at https://bugs.php.net/bug.php?id=61018&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=61018&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=61018&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=61018&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=61018&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=61018&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=61018&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=61018&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=61018&r=needscript Try newer version: https://bugs.php.net/fix.php?id=61018&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=61018&r=support Expected behavior: https://bugs.php.net/fix.php?id=61018&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=61018&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=61018&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=61018&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=61018&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=61018&r=dst IIS Stability: https://bugs.php.net/fix.php?id=61018&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=61018&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=61018&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=61018&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=61018&r=mysqlcfg
