Why Ignore Files

Part of the Version Control section of Coddy's Terminal journey — lesson 19 of 58.

Most real projects produce files you do not want in version control: build outputs, logs, environment secrets, editor caches, and files generated by tools.

Tracking those files would clutter every git status output, bloat the repository, and risk leaking sensitive data like API keys.

Git solves this with a special file called .gitignore. It lives at the root of your repo and lists patterns Git should skip.

node_modules/
.env
*.log
build/

Files matching any pattern in .gitignore become invisible to Git: they will not show up as untracked, will not be stageable, and will not be committed.

The .gitignore file itself is usually committed to the repo so everyone working on the project shares the same ignore rules.

Challenge

Beginner

The folder contains app.js and a junk file debug.log. Initialize the repo, create a .gitignore file containing the single line *.log, then run git status --short.

Only .gitignore and app.js should appear as untracked. debug.log should not.

Cheat sheet

.gitignore lists patterns for files Git should skip (untracked, unstageable, uncommitted). Place it at the repo root and commit it.

node_modules/   # ignore a directory
.env            # ignore a specific file
*.log           # ignore by extension
build/          # ignore a build folder

Try it yourself

Terminal