git ignore

NAME

gitignore - Specifies intentionally untracked files to ignore

SYNOPSIS

$GIT_DIR/info/exclude, .gitignore

DESCRIPTION

A gitignore file specifies intentionally untracked files that git should ignore. Files already tracked by git are not affected; see the NOTES below for details.

Each line in a gitignore file specifies a pattern. When deciding whether to ignore a path, git normally checks gitignore patterns from multiple sources,
with the following order of precedence, from highest to lowest (within one level of precedence, the last matching pattern decides the outcome):

Patterns read from the command line for those commands that support them.

Patterns read from a .gitignore file in the same directory as the path, or in any parent directory, with patterns in the higher level files (up to the toplevel of the work tree) being
overridden by those in lower level files down to the directory containing the file. These patterns match relative to the location of the .gitignore file. A project normally includes such.gitignore files
in its repository, containing patterns for files generated as part of the project build.

Patterns read from $GIT_DIR/info/exclude.

Patterns read from the file specified by the configuration variable core.excludesfile.

Which file to place a pattern in depends on how the pattern is meant to be used. Patterns which should be version-controlled and distributed to other repositories via clone (i.e., files that all developers will
want to ignore) should go into a .gitignore file. Patterns which are specific to a particular repository but which do not need to be shared with other related repositories (e.g., auxiliary files that live inside the repository but
are specific to one user’s workflow) should go into the $GIT_DIR/info/exclude file. Patterns which a user wants git to ignore in all situations (e.g., backup or temporary files generated by the user’s editor of choice) generally
go into a file specified by core.excludesfile in the user’s ~/.gitconfig.

The underlying git plumbing tools, such as git ls-files and git read-tree, read gitignore patterns
specified by command-line options, or from files specified by command-line options. Higher-level git tools, such as git status and git add, use patterns from the sources specified
above.

PATTERN FORMAT

A blank line matches no files, so it can serve as a separator for readability.

A line starting with # serves as a comment.

An optional prefix ! which negates the pattern; any matching file excluded by a previous pattern will become included again. If a negated pattern matches, this will override
lower precedence patterns sources.

If the pattern ends with a slash, it is removed for the purpose of the following description, but it would only find a match with a directory. In other words, foo/ will match a directoryfoo and
paths underneath it, but will not match a regular file or a symbolic link foo (this is consistent with the way how pathspec works in general in git).

If the pattern does not contain a slash /, git treats it as a shell glob pattern and checks for a match against the pathname relative to the location of the .gitignore file
(relative to the toplevel of the work tree if not from a .gitignore file).

Otherwise, git treats the pattern as a shell glob suitable for consumption by fnmatch(3) with the FNM_PATHNAME flag: wildcards in the pattern will not match a / in the pathname. For example, "Documentation/*.html"
matches "Documentation/git.html" but not "Documentation/ppc/ppc.html" or "tools/perf/Documentation/perf.html".

A leading slash matches the beginning of the pathname. For example, "/*.c" matches "cat-file.c" but not "mozilla-sha1/sha1.c".

NOTES

The purpose of gitignore files is to ensure that certain files not tracked by git remain untracked.

To ignore uncommitted changes in a file that is already tracked, use git update-index --assume-unchanged.

To stop tracking a file that is currently tracked, use git rm --cached.

EXAMPLES

$ git status
[...]
# Untracked files:
[...]
#       Documentation/foo.html
#       Documentation/gitignore.html
#       file.o
#       lib.a
#       src/internal.o
[...]
$ cat .git/info/exclude
# ignore objects and archives, anywhere in the tree.
*.[oa]
$ cat Documentation/.gitignore
# ignore generated html files,
*.html
# except foo.html which is maintained by hand
!foo.html
$ git status
[...]
# Untracked files:
[...]
#       Documentation/foo.html
[...]

Another example:

$ cat .gitignore
vmlinux*
$ ls arch/foo/kernel/vm*
arch/foo/kernel/vmlinux.lds.S
$ echo '!/vmlinux*' >arch/foo/kernel/.gitignore

The second .gitignore prevents git from ignoring arch/foo/kernel/vmlinux.lds.S.

We don’t need Git to version everything in our projects, be it compiled source, files with passwords, or temporary files that editors love to create. Usually keeping stuff out of your VCS’ hands is a task that is hard to manage and annoying to set up. Not with
Git! Using the

.gitignore

file
along with some other options, we’re going to learn how to set up per-project and per-user ignores.





The easiest and simplest way is to create a

.gitignore

file
in your project’s root directory. The files you choose to ignore here take affect for all directories in your project, unless if they include their own

.gitignore

file.
This is nice since you have one place to configure ignores unlike SVN’s svn:ignore which must be set on every folder. Also, the file itself can be versioned, which is definitely good.

Here’s a basic

.gitignore

:

$ cat .gitignore

# Can ignore specific files
.DS_Store

# Use wildcards as well
*~
*.swp

# Can also ignore all directories and files in a directory.
tmp/**/*

Of course, this could get a lot more complex. You can also add exceptions to ignore rules by starting the line with

!

.
See an example of this at the GitHub
guide on ignores.

Two things to keep in mind with ignoring files: First, if a file is already being tracked by Git, adding the file to

.gitignore

won’t
stop Git from tracking it. You’ll need to do

git
rm --cached <file>

to keep the file in your tree and then ignore it. Secondly, empty directories do not get tracked by Git. If you want them to be tracked, they need to have something in them. Usually doing a

touch
.gitignore

is enough to keep the folder tracked.

You can also open up

$GIT_DIR/info/exclude

(

$GIT_DIR

is
usually your

.git

folder)
and edit that file for project-only ignores. The problem with this is that those changes aren’t checked in, so use this only if you have some personal files that don’t need to be shared with others on the same project.

Your final option with ignoring folders is adding a per-user ignore by setting up a

core.excludesfiles

option
in your config file. You can set up a

.gitignore

file
in your HOME directory
that will affect all of your repositories by running this command:

git
config --global core.excludesfile ~/.gitignore

Read up on the manpage if
you’d like to learn more about how ignores work. As always, if you have other ignore-related tips let us know in the comments.