Gitignore Patterns

The patterns inside .gitignore follow a few simple rules:

• secret.txt: ignore an exact filename anywhere in the repo
• *.log: ignore every file ending in .log
• build/: ignore the entire build directory and everything inside it

• logs/*.tmp: ignore .tmp files inside logs/ only
• #: starts a comment line; ignored by Git
• !important.log: an exception. Even if a previous rule matched it, this file is not ignored

Order matters when you mix rules and exceptions. Later patterns override earlier ones for files they both match.

One important warning: .gitignore only affects files that are not yet tracked. If a file was already committed, adding it to .gitignore will not stop Git from tracking it. You would need to remove it from the index first.