Command Values¶
One of the primary uses of Idio is to orchestrate commands for which the value is the exit status of the command and can be used as a boolean in (logical) expressions.
printf "sleep 1 is %s\n" (sleep 1)
if (sleep 1) {
printf "still tired!\n"
}
printf "done sleeping!\n"
$ idio print-sleep
sleep 1 is #t
still tired!
done sleeping!
Alternatively, replacing sleep 1
with a call to the external
command false
:
printf "false is %s\n" (false)
if (false) {
printf "untrue?\n"
} {
printf "definitely false!\n"
}
printf "done falsifying!\n"
$ idio print-false-1
Nothing!
That’s because on the first line we ran an external command that fails
and the default behaviour of Idio is much like enabling set
-e
in other shells. We can disable that (later!) or comment the
first line out:
;printf "false is %s\n" (false)
if (false) {
printf "untrue?\n"
} {
printf "definitely false!\n"
}
printf "done falsifying!\n"
$ idio print-false-2
definitely false!
done falsifying!
This time false
doesn’t cause Idio to exit because it is
being used in a logical expression, much like in a regular shell:
if false ; then
echo "untrue?"
else
echo "definitely false!"
fi
Thoughts¶
There’s generally little value to be had in printing the value of an
external command as it can only be #t
or #f
(and you won’t see
#f
most of the time as Idio will have exited). The
details of the command are kept in Job Control data.
Last built at 2024-11-10T07:11:43Z+0000 from 77077af (dev) for Idio 0.3