How to ignore files in Git

How to ignore files in Git

tl;dr: We can tell git to ignore files using .gitignore and exclude.

In the home directory, we can set the global .gitignore
From within the project repository, there's the project .gitignore andpersonal exclude file (found within the local .git folder).
Rules in the subdirectories override the rules in the parent directories.

On .gitignore and exclude files

core.excludesfile
- Global .gitignore
- Ignore files across all git repositories of the current user in the system.
- Example: Files related to the OS and code editor
  - macOS.gitignore,
  - VisualStudioCode.gitignore
- Configure using --global option
  - Below it's named .gitignore but it can be any file name (e.g. .gitignore_global).
  - By convention, this is saved in the same location as the global gitconfig (in the home directory) but it can be in another location.
```
  nano ~/.gitignore
```
  - Specify the path to the .gitignore file
```
  git config --global core.excludesfile ~/.gitignore
```
  - Additional patterns can be appended using:
```
  echo .DS_Store >> ~/.gitignore
```
  - ⏩ Set global .gitignore
  - It's also possible to set values using --system and the --local options
.gitignore
- Project .gitignore
- Ignore files common across all copies of the current project repository.
- Example: File patterns related to the project and the programming language
  - Node.gitignore
  - config.json (because this contains the token)
```
  echo config.json >> .gitconfig
```
- Version-controlled, committed and shared with anyone who clones the repository.
- There can be multiple .gitignore in a repository but the convention is to place one in the top level directory. Same level as the local .git folder
.git/info/exclude
- Personal exclude
- Ignore files within the current copy of the project repository.
- Example: File patterns related to personal workflow and development tools
  - Personal commit.template saved in .gitmessage.txt
```
echo .gitmessage.txt >> .git/info/exclude
```
- exclude is a file located in the local .git folder. This file is not committed to the repository.
- ⏩ Display .git folder on Visual Studio Code

More .gitignore templates

Github maintains a collection of .gitignore templates.
Toptotal gitignore.io can be used to generate .gitignore files.