how to add a file to gitignore after commit code example

Example 1: apply gitignore to current commit

#First commit all changes
git rm -r --cached .
git add .
git commit -m ".gitignore updated"

Example 2: git ignore after commit

git rm --cached /\*.exe

Example 3: how to add filer to git ignore

go to the gitignore file, add the name of the file to ignore