Even if we extend the flag to be an n-flag with a numerical input, we
already have other Unix-tools to take care of us much more flexibly,
e.g. with head(1) you can easily get the first 10 outputs with
slstatus -s | head -n 10,
but also e.g. discard the first one and then get the consecutive 10
outputs.
For the X11-root-window-name, you can limit the runtime with timeout(1)
or a comparable solution.
This reverts commit fa8b939990.
d-flag: There's no need for that, use the &-operator or fork+exec in a
non-shell-context. In the latter case you get the PID for free.
v-flag: If you want to find out which version of a package is installed,
consult your package manager. That's his job.