note 17836 added to function.system

I have a php program called test.php,and test.php will call an external tcl script called hello.tcl by using system() function. Moreover,in hello.tcl, it will call three external command,exec(a),exec(b),and exec(c). a.c is like default OS command b is the execute command by c language. If I directly call hello.tcl from Unix shell,it's OK. Hence,it will execute exec(a),exec(b),exec(c). But if we called this from test.php this failed like in exec(b),why? b is the c program that I write. If seems the program entered the exec(b) and failed -- http://www.php.net/manual/en/function.system.php http://master.php.net/manage/user-notes.php?action=edit+17836 http://master.php.net/manage/user-notes.php?action=delete+17836 http://master.php.net/manage/user-notes.php?action=reject+17836