#27938 [NEW]: Variable variable causing undefined variable error

From: davelowe at davelowe dot net Operating system: Windows 2000 Pro PHP version: 4.3.5 PHP Bug Type: Variables related Bug description: Variable variable causing undefined variable error Description: ------------ I have a column value coming back from a mysql query that is '%$g_userName' Now, when I look at the column for each row and see a leading '%', I know that the value is actually the name of a variable that exists in my application. Here's a code snippet, where $name contains the column's value as returned by mysql (the value is '%$g_userName'): if (substr($name, 0, 1) == '%') { $actualName = substr($name, 1, strlen($name) - 1); $name = $$actualName; } When the code above gets executed, I get the following error: Notice: Undefined variable: $g_userName in C:\htdocs\ebbs\scripts\rightMenu_inc.php on line 51 I added the following immediately after the if {...} to make sure $g_userName actually exists and contains a value: echo $g_userName.'<br />'; And now I get the following: Notice: Undefined variable: $g_userName in C:\htdocs\ebbs\scripts\rightMenu_inc.php on line 51 dave Where 'dave' is the value I had hard-coded in $g_userName. Reproduce code: --------------- $g_userName = 'dave'; $name = '$'.'g_userName'; $trueName = $$name; echo $trueName; Expected result: ---------------- dave Actual result: -------------- Notice: Undefined variable: $g_userName in C:\htdocs\ebbs\scripts\pageFooter_inc.php on line 7 -- Edit bug report at http://bugs.php.net/?id=27938&edit=1 -- Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=27938&r=trysnapshot4 Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=27938&r=trysnapshot5 Fixed in CVS: http://bugs.php.net/fix.php?id=27938&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=27938&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=27938&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=27938&r=needscript Try newer version: http://bugs.php.net/fix.php?id=27938&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=27938&r=support Expected behavior: http://bugs.php.net/fix.php?id=27938&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=27938&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=27938&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=27938&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=27938&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=27938&r=dst IIS Stability: http://bugs.php.net/fix.php?id=27938&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=27938&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=27938&r=float