main: Exit on Control-c

Use `with-user-abort` to exit on a Control-c SIGINT.

Used the following tutorial for inspiration:
https://stevelosh.com/blog/2021/03/small-common-lisp-cli-programs/#s12-errors

Apparently Control-c should exit with code 130 according to this:
https://tldp.org/LDP/abs/html/exitcodes.html

Followed these Stack Overflow answers to turn off the interactive
debugger in an implementation independent way:
https://stackoverflow.com/questions/3074586/how-to-turn-off-the-debugger-in-sbcl/3074698#3074698
https://stackoverflow.com/questions/69280179/unmatched-close-parenthesis-when-sbcl-debugger-is-turned-off

This still opens the interactive debugger if Control-c is pressed before
`(main)` is called, but I don't know if there's any way to prevent that.

0 files changed, 0 insertions, 0 deletions