Git: Never Commit Changed Files (But still keep original revisioned.)

Question

What is a good git practice to denote that a changed file should never be committed?

For example, for a WordPress theme development project, I am tracking the original WordPress files in git; and the wp-config.php config file, which contains local info that only pertains to the current system, needs to be changed but I don't want to commit it to git.

In Perforce, I used to save this type of event as a numbered changelist and never check it in. I was wondering whether a similar trick is available with git.

Answer 1

If you still want to keep wp-config.php versioned, but ignore any local change to it:

git update-index --assume-unchanged wp-config.php

This is different that a .gitignore, which would only work if you remove first wp-config.php from the index:

git rm --cache `wp-config.php`
echo wp-config.php >> .gitignore