Understanding the .gitignore file¶

Introduction¶

When you make commits in a git repository, you choose which files to stage and commit by using git add FILENAME and then git commit. But what if there are some files that you never want to commit? It's too easy to accidentally commit them (especially if you use git add . to stage all files in the current directory). That's where a .gitignore file comes in handy. It lets Git know that it should ignore certain files and not track them.

How .gitignore works¶

Here's how it works. A .gitignore file is a plain text file where each line contains a pattern for files/directories to ignore. Generally, this is placed in the root folder of the repository.

Literal File Names¶

The easiest pattern is a literal file name, for example:

.DS_Store

This will ignore any files named .DS_Store, which is a common file on macOS.

Directories¶

You can ignore entire directories, just by including their paths and putting a / on the end:

node_modules/
logs/

If you leave the slash off of the end, it will match both files and directories with that name.

Wildcard¶

The * matches 0 or more characters (except the /). So, for example, *.log matches any file ending with the .log extension.

Another example is *~, which matches any file ending with ~, such as index.html~

You can also use the ?, which matches any one character except for the /.

Negation¶

You can use a prefix of ! to negate a file that would be ignored.

*.log
!example.log

In this example, example.log is not ignored, even though all other files ending with .log are ignored.

But be aware, you can't negate a file inside of an ignored directory:

logs/
!logs/example.log

Due to performance reasons, git will still ignore logs/example.log here because the entire logs directory is ignored.

Double Asterisk¶

** can be used to match any number of directories.

• **/logs matches all files or directories named logs (same as the pattern logs)

• **/logs/*.log matches all files ending with .log in a logs directory

• logs/**/*.log matches all files ending with .log in the logs directory and any of its subdirectories

** can also be used to match all files inside of a directory, so for example logs/** matches all files inside of logs.

Comments¶

Any lines that start with # are comments:

1# macOS Files
2.DS_Store

Automatically create .gitignore file from VS Code¶

The gitignore VS Code extension included in the list of recommended extensions for this repository automates the creation of .gitignore files.

Usage¶

Start command palette (with Ctrl+Shiftt+P or F1) and start typingAdd gitignore. Then select a programming language from the list.

It is possible to append multiple programming languages like Python and R. Add first Python and then, if you try to add R you will see these options:

Append Append to existing .gitignore file
Overwrite Overwrite existing .gitignore file

Choose append and you will see the following message:

Appended Python.gitignore to the existing .gitignore in the project root