Can this scrolling-text package be implemented into (or used by) polybar somehow?

[ghost]

zscroll (Link) is a text scroller for panels or the shell, and it's mostly used for scrolling song name from mpc or mpd. However, using custom script, I cannot implement it into polybar. The command to run the software is:
zscroll -d 0.2 -n -u -M "mpc status" -s 1 -m "paused" -s 0 "mpc current"
With the above command, the terminal will continuously output scrolling song name when mpc is playing and stop the scroll when mpc is paused. But when I create a custom script (with ~/.config/scripts/zscroll containing only the above command), like:

[module/mpc]
type = custom/script
exec = ~/.config/scripts/zscroll
tail = true
format-background = #999
format-foreground = #000

then add it to the modules list & restart the bar, nothing appears at all. Running:
/usr/bin/env sh -c ~/.config/scripts/zscroll
still executes normally with expected behavior in terminal. The error log shows nothing related to the custom script module at all.

So my question is: how can this be implemented into polybar using custom script? Or: [Feature Request] Could this be a new feature for the mpd module in the future?

Thank you for reading.

[jaagr]

Try this

script:

#!/bin/sh
if ! mpc >/dev/null 2>&1; then
  echo Server offline
  exit 1
elif mpc status | grep -q playing; then
  ( mpc current | zscroll -l 10 -d 0.1 -n ) &
else
  echo Not playing
fi
# Block until an event is emitted
mpc idle >/dev/null

module config:

[module/script]
type = custom/script
exec = ~/mpc_zscroll.sh
tail = true
interval = 0

[ghost]

Wow a much cleaner approach. Thank you so much! This could be included in the wiki if anyone prefers :)

[noctuid]

For anyone else who stumbles across this, you can also keep the zscroll command as-is if you want or need to. I've added an example to the zscroll readme.

[jaagr]

@noctuid nice. Couldn't it be simplified further by just using:

[module/mpd]
type = custom/script
exec = zscroll -n -u -b "♪ x" -d 0.3 -M "mpc status" -m "playing" -b " " -s 1 -m "paused" -b " " -s 0 "mpc current"
tail = true

[noctuid]

No, I couldn't find a way to get it working directly with exec =. I'd also rather not have a line that long in my config; is there some way to break lines?

[jaagr]

No, it's not possible.