How to write a program to catch every SIGINT and print "hello"

[Nathaniel W Griswold]

I wanted to understand a limitation of the repl of the rash package (github issue https://github.com/willghatch/racket-rash/issues/78) as well as in the racket repl, i guess, and see if i could do a quick hack to get something working.

Anyway, i just wanted to catch SIGINT without using something like the `unix-signals` package from Tony Garnock-Jones. I just did this:

```
(module blah racket
(let loop ()
(define (read k)
(with-handlers ([exn:break? (λ (e) (display "=BREAK=") (k #f))])
(k (read-line))))

(display "> ")
(let ([result (call/cc read)])
(when result
(display result))
(newline)
(loop))))
```

1) It catches all breaks and my program won't quit =). Is there a way to discern if the break is a SIGINT so i can continue only on that signal and abort otherwise? I guess, should i just check that it's not a exn:break:terminate or exn:break:hang-up, or... ?

2) Are there any glaring mistakes in what i wrote other than the problems of (1)?

Any good way to do this?

Nate

[Nathaniel W Griswold]

Ok, i think i found in the kernel where this is set up.

```
(define 1/check-for-break
...
(let ((exn:break*_0
(let ((tmp_0 (thread-pending-break t_0)))
(if (eq? tmp_0 'hang-up)
exn:break:hang-up/non-engine
(if (eq? tmp_0 'terminate)
exn:break:terminate/non-engine
exn:break/non-engine)))))
(begin
(set-thread-pending-break! t_0 #f)
(lambda ()
(call-with-escape-continuation
(lambda (k_0)
(raise
(|#%app|
exn:break*_0
"user break"
(current-continuation-marks)
k_0)))))))

```

Can i just hack this to check `tmp_0` for the value `'interrupt` or is that wishful thinking? I have no idea what i'm doing =). I am just impatient and want a SIGINT.

There must be some reason SIGINT is not explicitly supported, or i must be missing something.

Nate

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