There are a number of utilities that handle copy/paste, but `xclip` is probably the most widely used.
Screenshots can also be done a number of ways, but `scrot` is my favorite. The two most useful flags to pass with it are `-s` and `-d`.
As for `launchctl`, `systemctl` is what you want to use to do the same things.
Note that these equivalents all address the same functionality, but the syntax may be different.