git/Documentation/gitignore.txt

gitignore(5)
============

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.
Note that all the `gitignore` files really concern only files
that are not already tracked by git;
in order to ignore uncommitted changes in already tracked files,
please refer to the 'git update-index --assume-unchanged'
documentation.

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.

Patterns have the following 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
   directory `foo` 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/{asterisk}.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, "/{asterisk}.c" matches "cat-file.c" but not
   "mozilla-sha1/sha1.c".

An example:

--------------------------------------------------------------
    $ 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`.

Documentation
-------------
Documentation by David Greaves, Junio C Hamano, Josh Triplett,
Frank Lichtenheld, and the git-list <git@vger.kernel.org>.

GIT
---
Part of the linkgit:git[1] suite