Exec is a Minecraft server plugin that makes possible to run external scripts via commands. The scripts can be written with Bash or Python for example and the code changes don't need a server restart.

PlaceholderAPI is required. You might also want to use mcrcon for script output.

Config

commands:
    examplecommand:
        script: "/path/to/your/script %player_name% %args%"
        permission: "exec.example"

The Exec config looks like this. You can use the following placeholders:

%args% means all arguments provided to the command.
%arg_1%, %arg_2% can be used to read arguments too.
PlaceholderAPI is supported (and usually required). %player_name% is the most useful one.

You can use /exec reload to reload the config.