installing pear

hi all i'm trying to install pear on my web server. i don't have shell access and it seems that php is running in safe mode. so this dont works: <?php echo which php; // if this does not work, also try echo PHP_BIN; ?> here is the error message: Warning: shell_exec(): Cannot execute using backquotes in Safe Mode in /www/web240/html/test/whichphp.php on line 12 but without this information i can'd define the path for the php executable. and without the path the webinstaller doesn't work. here is the error message: ERROR(S): php.exe path, optional (CLI command tools): Please fill this path, you can use $prefix, $php_dir or a full path. i tried to use $php_dir. here is the result: Error Warning: tempnam(): open_basedir restriction in effect. File(/tmp) is not within the allowed path(s): (/www/web240/) in /www/web240/html/pear/go-pear.php on line 391 mkdir failed: System's Tempdir failed, trying to use $prefix/tmp ...mkdir failed: /www/web240/html/pear/tmp/gopertcdGN chdir /www/web240/html/pear/tmp/gopertcdGN ... failed another problem is /www/web240/html/pear/tmp/gopertcdGN i suppose, that the webinstaller made this file. the problem is, that this file is in chmod 0600. and i can't change it. so i can't delete it. thx for helping Aleksej p.s. sorry for bad english