14. Writing Secure Shell Scripts

Writing secure shell scripts?! How can shell scripts be secure when you can read the source code?

Any system that depends on concealing implementation details is attempting to use security by obscurity, and that is no security at all. Just ask the major software manufacturers whose source code is a closely guarded trade secret, yet whose products are incessantly vulnerable to exploits written by people who have never seen that source code. Contrast that with the code from OpenSSH and OpenBSD, which is totally open, yet very secure.