Fork: Difference between revisions

=={{header|Racket}}==

Looks like there are two popular things that people do for this task, so here

are both. First, run some subprocess independently of Racket:

<lang Racket>

#lang racket

(define-values [P _out _in _err]

(subprocess (current-output-port) (current-input-port) (current-error-port)

(find-executable-path "du") "-hs" "/usr/share"))

;; wait for process to end, print messages as long as it runs

(let loop () (unless (sync/timeout 10 P) (printf "Still running...\n") (loop)))

</lang>

Output:

<pre>

Still running...

Still running...

Still running...

...snip...

15G /usr/share

</pre>

Second, using fork() in its raw form, which is doable in racket, but as unsafe as you'd expect it to be:

<lang Racket>

#lang racket

(require ffi/unsafe)

(define fork (get-ffi-obj 'fork #f (_fun -> _int)))

(printf ">>> fork() => ~s\n" (fork))

</lang>

Output:

<pre>

>>> fork() => 23834

>>> fork() => 0

</pre>