Description: ------------ When System_Command is instantiated, $options['SHELL'] doesn't have a path to a valid shell, which causes all commands to fail. The problem is that which() is called with the (possibly null) $in_shell parameter to the constructor. which() only checks if a path is executable, not if it is a file which is executable. This causes it to return the (bare) first directory with the execute bit listed in the path when it is called with no arguments. The attached patch adds a call to is_file(), and fixes the issue for me. It may be a good idea to have a check for a null argument before any processing is done in which(), but this change seemed less intrusive. --- Command.php.orig 2004-07-26 13:56:28.000000000 -0700 +++ Command.php 2004-07-26 13:58:49.000000000 -0700 @@ -417,7 +417,7 @@ foreach ($paths as $path) { $location = $path . '/' . $in_cmd; - if (is_executable($location)) { + if (is_file($location) && is_executable($location)) { return $location; } } Reproduce code: --------------- <?php require 'System/Command.php'; $sc = new System_Command; print $sc->options['SHELL']; ?> Expected result: ---------------- 'SHELL' should be set to /bin/sh Actual result: -------------- 'SHELL' is set to /bin/

This is really a showstopper, shouldn't be to hard to fix this and roll out a new release?! The patched line works fine here...

This bug is not fixed. I still have the same error, just because no NULL check is done - which was described as a possible solution by Ian. It can be fixed some simple lines at the beginning of the function: function which($program, $fallback = false) { if ($program === null) { return false; } ...