Note that parsing of the shebang line may not always work as expected...
#!/usr/bin/php -dmemory_limit=512M -dsafe_mode=Off
<?php
print "memory_limit=".ini_get("memory_limit")."\n";
print "safe_mode=".ini_get("safe_mode")."\n";
?>
gives...
$ ./test.php
PHP: Invalid configuration directive
memory_limit=512M -dsafe_mode
safe_mode=
