title: Perl disable shell access
body: <p>Certain builtins like <code>system</code> and <code>exec</code> (as well as backticks) will use the shell (I think <code>sh</code> by default) if passed a single argument containing shell metacharacters. If I want to write a portable program that avoids making any assumptions about the underlying shell, is there a pragma or some other option I can use to either disable shell access or trigger a fatal error immediately?</p>