cmd_error

When unwrapping Options and Results it's oddly annoying to print a simple error message and exit. This crate introduces the ErrExit trait which allows exactly that.

For example,

use cmd_error::ErrExit;

fn main() {
    let path = std::env::args().nth(1)
        .unwrap_exit("file path not passed");
    
    let file = std::fs::read_to_string(&path)
        .unwrap_exit(&format!("file {} not found", path));

    // ...
}

Why not use expect? Panic message aren't for users, they're for the programmers.

This crate also exports the function print_err_and_exit which unsurprisingly prints an error message and exits.

Exits with an exit code of 1. Errors are printed to stderr.