Is your feature request related to a problem? Please describe.

I have a set of scripts which I use in my polybar config. I have a wrapper script to format them correctly; so i usually call them using the following syntax; ~/.config/sysinfo/sysinfo.sh -n pulseaudio -a cyan. The reason I do have a wrapper script is I use these scripts across different setups.

Some other tools allow to custom set environment variables; so I do some customization of environment variables. (For example; the sysinfo.sh -n <name> is analogous to name=<name> sysinfo.sh)

Why does polybar need this feature?

This would help users organize their custom scripts; as there can be one main block like the following;

[module/skeleton]
type = custom/script
tail = true
interval = 0
label = %output%
format = <label>
exec = ~/.config/sysinfo/sysinfo.sh

And then each custom script section could be defined like following;

[module/clock-script]
inherit = module/skeleton
environment = 'name=clock accent=cyan'

Which would make the config file more modular and organized.

Describe the solution you'd like

Add a config option environment to a script that gets parsed to the beginning of a custom script's exec line.

Describe alternatives you've considered

I currently read command line arguments; but it takes more work to do so.

Additional context

Not really a vital or needed improvement; but I was thinking it could be trivial to implement.