gitignore how to ignore file in another folder code example

Example 1: how to put files into gitignore

$ echo debug.log >> .gitignore
$ git rm --cached debug.log
rm 'debug.log'
$ git commit -m "Start ignoring debug.log"

Example 2: how to put access.log in gitignore

git rm --cached [file]
git update-index --assume-unchanged [file]