exec_program.rs

#[fixed_stack_segment]
fn exec_program(program: &str, args: &[~str]) {
    do program.to_c_str().with_ref() |c_program| {
        // I don't much care about the ownership of the strings here
        // at this point, so let's just fail if execvp isn't working.
        unsafe {
            let c_args = args.map(|arg| { arg.to_c_str().unwrap() });
            // c_args needs a NULL attached to the end though. Here's what I tried:
            // let c_args = args.map(|arg| { arg.to_c_str().unwrap() }) + [ptr::null()];  // this screams about unconstrained types.
            execvp(c_program, vec::raw::to_ptr(c_args));
            // perror("Running tmux failed:".to_c_str().unwrap()); // Super horrific, apparently, let's use it for debugging only.
        }
        fail!(fmt!("Couldn't exec %s", program));
    }
}