Is it possible to set the path using an install shell script?

I plan to create a program using shell and is it possible to edit the user's path and alias? Or is it normal etiquette to post an instruction that says something like:

1. "past开发者_如何学Pythone this in your path in .bash_profile"
2. "paste this in your alias in .bash_profile"

like the one shown here: https://github.com/icefox/git-achievements/blob/gh-pages/README

It's poor etiquette to do either. Create a shell script that invokes your application using exec, and put that in $PREFIX/bin or $PREFIX/sbin.