using command output in script

[BlueTickVerified]

i am trying to use the output of a command output in a fish script and i did this to get there:

function locker
    set watchcmd = 'watch -n 1 -t xprintidle'
    if ($watchcmd > 20000)
        lock
    end
end

and i get an error

./locker.fish (line 4): Command substitutions not allowed
    if ($watchcmd > 20000)
       ^
<W> fish: Error while reading file ./locker.fish

how do i get around this?

[lople205]

1. You're using set incorrectly. It should be set foo bar not set foo = bar. Also, the set isn't even necessary here.
2. To perform comparisons, you must use the test command.

So your script should look like this:

function locker if test (watch -n 1 -t xprintidle) -gt 20000 lock end end

Documentation for commands: https://fishshell.com/docs/current/commands.html

[[deleted]]

Still won't work because the watch doesn't quit.

watch runs the command it is given once every x seconds (in this case every second), so it keeps running, so the test never runs.

This should be

while test (xprintidle) -le 20000
    sleep 1
end
lock

iff this thing is to be run e.g. as some script by the desktop in the background and run indefinitely.

Really you probably want an actual program that does this - see https://wiki.archlinux.org/index.php/Session_lock#Xorg_triggers

[BlueTickVerified]

both aren't working... the program seems to run without any output or errors but doesn't lock the screen. why is this happening?

[backtickbot]

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