Master .gitignore: How to Exclude Files and Folders in Git

What is a .gitignore file?

A .gitignore file is a plain‑text file placed in a Git repository that lists file and directory patterns Git should ignore, preventing them from being tracked or committed.

File statuses in a Git repository

tracked

– files that Git knows about (added with git add and committed). untracked – new files in the working directory that have not been added. ignored – files explicitly excluded via .gitignore; Git does not consider them at all.

Creating a .gitignore file

Typically the file is created in the repository root, but it can exist in any folder. On macOS or Linux you can create it from the terminal: touch .gitignore Hidden files (those beginning with a dot) are not shown by ls unless you use the -a flag:

ls -a

Typical entries to ignore

Operating‑system generated files (e.g., .DS_Store on macOS).

Editor and IDE configuration files.

Compiled artifacts such as .o files.

Dependency directories like node_modules.

Sensitive files containing credentials, e.g., .env.

Runtime logs, e.g., .log files.

Pattern syntax for ignoring files and folders

Specify the path relative to the repository root to ignore a single file: /text.txt Ignore a file in a subdirectory: /test/text.txt Ignore all files with a given name anywhere: text.txt Ignore an entire directory (trailing slash required): test/ Use a wildcard to ignore files by prefix or extension:

img*

*.md

Negate a pattern with an exclamation mark to keep a specific file while ignoring the rest:

# ignore all .md files
*.md
# but keep README.md
!README.md

Note: Negation does not work for files inside a directory that is already ignored.

Removing files that were already committed

Git can only ignore files that are not yet tracked. To stop tracking a file that has already been committed, follow these steps:

# add the file to .gitignore
 echo ".env" >> .gitignore
# remove it from the index without deleting the local copy
 git rm --cached .env
# stage the updated .gitignore
 git add .gitignore
# commit the change
 git commit -m "update ignored files"

Using git status will show the file as no longer part of the repository, while it remains on the local filesystem.

Best practices and conclusion

Create a comprehensive .gitignore at the start of a project to list all files and patterns you never want to commit. Remember that Git only ignores untracked files; to retroactively ignore a tracked file you must remove it from the index as shown above. With these techniques you can keep your repository clean and avoid accidentally publishing sensitive or unnecessary files.