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GITATTRIBUTES(5) Git Manual GITATTRIBUTES(5)

NAME
gitattributes - defining attributes per path

SYNOPSIS
$GIT_DIR/info/attributes, .gitattributes

DESCRIPTION
A gitattributes file is a simple text file that gives attributes to pathnames.

Each line in gitattributes file is of form:

pattern attr1 attr2 ...

That is, a pattern followed by an attributes list, separated by whitespaces. When the pattern matches the path
in question, the attributes listed on the line are given to the path.

Each attribute can be in one of these states for a given path:

Set
The path has the attribute with special value "true"; this is specified by listing only the name of the
attribute in the attribute list.

Unset
The path has the attribute with special value "false"; this is specified by listing the name of the
attribute prefixed with a dash - in the attribute list.

Set to a value
The path has the attribute with specified string value; this is specified by listing the name of the
attribute followed by an equal sign = and its value in the attribute list.

Unspecified
No pattern matches the path, and nothing says if the path has or does not have the attribute, the
attribute for the path is said to be Unspecified.

When more than one pattern matches the path, a later line overrides an earlier line. This overriding is done
per attribute. The rules how the pattern matches paths are the same as in .gitignore files; see gitignore(5).
Unlike .gitignore, negative patterns are forbidden.

When deciding what attributes are assigned to a path, Git consults $GIT_DIR/info/attributes file (which has
the highest precedence), .gitattributes file in the same directory as the path in question, and its parent
directories up to the toplevel of the work tree (the further the directory that contains .gitattributes is
from the path in question, the lower its precedence). Finally global and system-wide files are considered
(they have the lowest precedence).

When the .gitattributes file is missing from the work tree, the path in the index is used as a fall-back.
During checkout process, .gitattributes in the index is used and then the file in the working tree is used as
a fall-back.

If you wish to affect only a single repository (i.e., to assign attributes to files that are particular to one
user’s workflow for that repository), then attributes should be placed in the $GIT_DIR/info/attributes file.
Attributes which should be version-controlled and distributed to other repositories (i.e., attributes of
interest to all users) should go into .gitattributes files. Attributes that should affect all repositories for
a single user should be placed in a file specified by the core.attributesfile configuration option (see git-
config(1)). Its default value is $XDG_CONFIG_HOME/git/attributes. If $XDG_CONFIG_HOME is either not set or
empty, $HOME/.config/git/attributes is used instead. Attributes for all users on a system should be placed in
the $(prefix)/etc/gitattributes file.

text
This attribute enables and controls end-of-line normalization. When a text file is normalized, its line
endings are converted to LF in the repository. To control what line ending style is used in the working
directory, use the eol attribute for a single file and the core.eol configuration variable for all text
files.

Set
Setting the text attribute on a path enables end-of-line normalization and marks the path as a text
file. End-of-line conversion takes place without guessing the content type.

Unset
Unsetting the text attribute on a path tells Git not to attempt any end-of-line conversion upon
checkin or checkout.

Set to string value "auto"
When text is set to "auto", the path is marked for automatic end-of-line normalization. If Git decides
that the content is text, its line endings are normalized to LF on checkin.

Unspecified
If the text attribute is unspecified, Git uses the core.autocrlf configuration variable to determine
if the file should be converted.

Any other value causes Git to act as if text has been left unspecified.

eol
This attribute sets a specific line-ending style to be used in the working directory. It enables
end-of-line normalization without any content checks, effectively setting the text attribute.

Set to string value "crlf"
This setting forces Git to normalize line endings for this file on checkin and convert them to CRLF
when the file is checked out.

Set to string value "lf"
This setting forces Git to normalize line endings to LF on checkin and prevents conversion to CRLF
when the file is checked out.

Backwards compatibility with crlf attribute
For backwards compatibility, the crlf attribute is interpreted as follows:

crlf text
-crlf -text
crlf=input eol=lf

End-of-line conversion
While Git normally leaves file contents alone, it can be configured to normalize line endings to LF in the
repository and, optionally, to convert them to CRLF when files are checked out.

Here is an example that will make Git normalize .txt, .vcproj and .sh files, ensure that .vcproj files
have CRLF and .sh files have LF in the working directory, and prevent .jpg files from being normalized
regardless of their content.

*.txt text

autocrlf = true

This does not force normalization of all text files, but does ensure that text files that you introduce to
the repository have their line endings normalized to LF when they are added, and that files that are
already normalized in the repository stay normalized.

If you want to interoperate with a source code management system that enforces end-of-line normalization,
or you simply want all text files in your repository to be normalized, you should instead set the text
attribute to "auto" for all files.

* text=auto

This ensures that all files that Git considers to be text will have normalized (LF) line endings in the
repository. The core.eol configuration variable controls which line endings Git will use for normalized
files in your working directory; the default is to use the native line ending for your platform, or CRLF
if core.autocrlf is set.

Note
When text=auto normalization is enabled in an existing repository, any text files containing CRLFs
should be normalized. If they are not they will be normalized the next time someone tries to change
them, causing unfortunate misattribution. From a clean working directory:

$ echo "* text=auto" >>.gitattributes
$ rm .git/index # Remove the index to force Git to
$ git reset # re-scan the working directory
$ git status # Show files that will be normalized
$ git add -u
$ git add .gitattributes
$ git commit -m "Introduce end-of-line normalization"

If any files that should not be normalized show up in git status, unset their text attribute before
running git add -u.

manual.pdf -text

Conversely, text files that Git does not detect can have normalization enabled manually.

weirdchars.txt text

If core.safecrlf is set to "true" or "warn", Git verifies if the conversion is reversible for the current
setting of core.autocrlf. For "true", Git rejects irreversible conversions; for "warn", Git only prints a
warning but accepts an irreversible conversion. The safety triggers to prevent such a conversion done to
the files in the work tree, but there are a few exceptions. Even though...

· git add itself does not touch the files in the work tree, the next checkout would, so the safety
triggers;

· git apply to update a text file with a patch does touch the files in the work tree, but the operation
is about text files and CRLF conversion is about fixing the line ending inconsistencies, so the safety

A filter driver consists of a clean command and a smudge command, either of which can be left unspecified.
Upon checkout, when the smudge command is specified, the command is fed the blob object from its standard
input, and its standard output is used to update the worktree file. Similarly, the clean command is used
to convert the contents of worktree file upon checkin.

One use of the content filtering is to massage the content into a shape that is more convenient for the
platform, filesystem, and the user to use. For this mode of operation, the key phrase here is "more
convenient" and not "turning something unusable into usable". In other words, the intent is that if
someone unsets the filter driver definition, or does not have the appropriate filter program, the project
should still be usable.

Another use of the content filtering is to store the content that cannot be directly used in the
repository (e.g. a UUID that refers to the true content stored outside Git, or an encrypted content) and
turn it into a usable form upon checkout (e.g. download the external content, or decrypt the encrypted
content).

These two filters behave differently, and by default, a filter is taken as the former, massaging the
contents into more convenient shape. A missing filter driver definition in the config, or a filter driver
that exits with a non-zero status, is not an error but makes the filter a no-op passthru.

You can declare that a filter turns a content that by itself is unusable into a usable content by setting
the filter.<driver>.required configuration variable to true.

For example, in .gitattributes, you would assign the filter attribute for paths.

*.c filter=indent

Then you would define a "filter.indent.clean" and "filter.indent.smudge" configuration in your .git/config
to specify a pair of commands to modify the contents of C programs when the source files are checked in
("clean" is run) and checked out (no change is made because the command is "cat").

[filter "indent"]
clean = indent
smudge = cat

For best results, clean should not alter its output further if it is run twice ("clean→clean" should be
equivalent to "clean"), and multiple smudge commands should not alter clean's output
("smudge→smudge→clean" should be equivalent to "clean"). See the section on merging below.

The "indent" filter is well-behaved in this regard: it will not modify input that is already correctly
indented. In this case, the lack of a smudge filter means that the clean filter must accept its own output
without modifying it.

If a filter must succeed in order to make the stored contents usable, you can declare that the filter is
required, in the configuration:

[filter "crypt"]
clean = openssl enc ...
smudge = openssl enc -d ...
required

with text (again, if specified and applicable).

In the check-out codepath, the blob content is first converted with text, and then ident and fed to
filter.

Merging branches with differing checkin/checkout attributes
If you have added attributes to a file that cause the canonical repository format for that file to change,
such as adding a clean/smudge filter or text/eol/ident attributes, merging anything where the attribute is
not in place would normally cause merge conflicts.

To prevent these unnecessary merge conflicts, Git can be told to run a virtual check-out and check-in of
all three stages of a file when resolving a three-way merge by setting the merge.renormalize configuration
variable. This prevents changes caused by check-in conversion from causing spurious merge conflicts when a
converted file is merged with an unconverted file.

As long as a "smudge→clean" results in the same output as a "clean" even on files that are already
smudged, this strategy will automatically resolve all filter-related conflicts. Filters that do not act in
this way may cause additional merge conflicts that must be resolved manually.

Generating diff text
diff
The attribute diff affects how Git generates diffs for particular files. It can tell Git whether to
generate a textual patch for the path or to treat the path as a binary file. It can also affect what line
is shown on the hunk header @@ -k,l +n,m @@ line, tell Git to use an external command to generate the
diff, or ask Git to convert binary files to a text format before generating the diff.

Set
A path to which the diff attribute is set is treated as text, even when they contain byte values that
normally never appear in text files, such as NUL.

Unset
A path to which the diff attribute is unset will generate Binary files differ (or a binary patch, if
binary patches are enabled).

Unspecified
A path to which the diff attribute is unspecified first gets its contents inspected, and if it looks
like text, it is treated as text. Otherwise it would generate Binary files differ.

String
Diff is shown using the specified diff driver. Each driver may specify one or more options, as
described in the following section. The options for the diff driver "foo" are defined by the
configuration variables in the "diff.foo" section of the Git config file.

Defining an external diff driver
The definition of a diff driver is done in gitconfig, not gitattributes file, so strictly speaking this
manual page is a wrong place to talk about it. However...

To define an external diff driver jcdiff, add a section to your $GIT_DIR/config file (or $HOME/.gitconfig
file) like this:

[diff "jcdiff"]
command = j-c-diff

First, in .gitattributes, you would assign the diff attribute for paths.

*.tex diff=tex

Then, you would define a "diff.tex.xfuncname" configuration to specify a regular expression that matches a
line that you would want to appear as the hunk header "TEXT". Add a section to your $GIT_DIR/config file
(or $HOME/.gitconfig file) like this:

[diff "tex"]
xfuncname = "^(\\\\(sub)*section\\{.*)$"

Note. A single level of backslashes are eaten by the configuration file parser, so you would need to
double the backslashes; the pattern above picks a line that begins with a backslash, and zero or more
occurrences of sub followed by section followed by open brace, to the end of line.

There are a few built-in patterns to make this easier, and tex is one of them, so you do not have to write
the above in your configuration file (you still need to enable this with the attribute mechanism, via
.gitattributes). The following built in patterns are available:

· ada suitable for source code in the Ada language.

· bibtex suitable for files with BibTeX coded references.

· cpp suitable for source code in the C and C++ languages.

· csharp suitable for source code in the C# language.

· fortran suitable for source code in the Fortran language.

· html suitable for HTML/XHTML documents.

· java suitable for source code in the Java language.

· matlab suitable for source code in the MATLAB language.

· objc suitable for source code in the Objective-C language.

· pascal suitable for source code in the Pascal/Delphi language.

· perl suitable for source code in the Perl language.

· php suitable for source code in the PHP language.

· python suitable for source code in the Python language.

· ruby suitable for source code in the Ruby language.

· tex suitable for source code for LaTeX documents.

Customizing word diff
You can customize the rules that git diff --word-diff uses to split words in a line, by specifying an
Sometimes it is desirable to see the diff of a text-converted version of some binary files. For example, a
word processor document can be converted to an ASCII text representation, and the diff of the text shown.
Even though this conversion loses some information, the resulting diff is useful for human viewing (but
cannot be applied directly).

The textconv config option is used to define a program for performing such a conversion. The program
should take a single argument, the name of a file to convert, and produce the resulting text on stdout.

For example, to show the diff of the exif information of a file instead of the binary information
(assuming you have the exif tool installed), add the following section to your $GIT_DIR/config file (or
$HOME/.gitconfig file):

[diff "jpg"]
textconv = exif

Note
The text conversion is generally a one-way conversion; in this example, we lose the actual image
contents and focus just on the text data. This means that diffs generated by textconv are not suitable
for applying. For this reason, only git diff and the git log family of commands (i.e., log,
whatchanged, show) will perform text conversion. git format-patch will never generate this output. If
you want to send somebody a text-converted diff of a binary file (e.g., because it quickly conveys the
changes you have made), you should generate it separately and send it as a comment in addition to the
usual binary diff that you might send.

Because text conversion can be slow, especially when doing a large number of them with git log -p, Git
provides a mechanism to cache the output and use it in future diffs. To enable caching, set the
"cachetextconv" variable in your diff driver’s config. For example:

[diff "jpg"]
textconv = exif
cachetextconv = true

This will cache the result of running "exif" on each blob indefinitely. If you change the textconv config
variable for a diff driver, Git will automatically invalidate the cache entries and re-run the textconv
filter. If you want to invalidate the cache manually (e.g., because your version of "exif" was updated and
now produces better output), you can remove the cache manually with git update-ref -d
refs/notes/textconv/jpg (where "jpg" is the name of the diff driver, as in the example above).

Choosing textconv versus external diff
If you want to show differences between binary or specially-formatted blobs in your repository, you can
choose to use either an external diff command, or to use textconv to convert them to a diff-able text
format. Which method you choose depends on your exact situation.

The advantage of using an external diff command is flexibility. You are not bound to find line-oriented
changes, nor is it necessary for the output to resemble unified diff. You are free to locate and report
changes in the most appropriate way for your data format.

A textconv, by comparison, is much more limiting. You provide a transformation of the data into a
line-oriented text format, and Git uses its regular diff tools to generate the output. There are several
advantages to choosing this method:

1. Ease of use. It is often much simpler to write a binary to text transformation than it is to perform

opaque to a human reader. For example, many postscript files contain only ascii characters, but produce
noisy and meaningless diffs.

The simplest way to mark a file as binary is to unset the diff attribute in the .gitattributes file:

*.ps -diff

This will cause Git to generate Binary files differ (or a binary patch, if binary patches are enabled)
instead of a regular diff.

However, one may also want to specify other diff driver attributes. For example, you might want to use
textconv to convert postscript files to an ascii representation for human viewing, but otherwise treat
them as binary files. You cannot specify both -diff and diff=ps attributes. The solution is to use the
diff.*.binary config option:

[diff "ps"]
textconv = ps2ascii
binary = true

Performing a three-way merge
merge
The attribute merge affects how three versions of a file are merged when a file-level merge is necessary
during git merge, and other commands such as git revert and git cherry-pick.

Set
Built-in 3-way merge driver is used to merge the contents in a way similar to merge command of RCS
suite. This is suitable for ordinary text files.

Unset
Take the version from the current branch as the tentative merge result, and declare that the merge has
conflicts. This is suitable for binary files that do not have a well-defined merge semantics.

Unspecified
By default, this uses the same built-in 3-way merge driver as is the case when the merge attribute is
set. However, the merge.default configuration variable can name different merge driver to be used with
paths for which the merge attribute is unspecified.

String
3-way merge is performed using the specified custom merge driver. The built-in 3-way merge driver can
be explicitly specified by asking for "text" driver; the built-in "take the current branch" driver can
be requested with "binary".

Built-in merge drivers
There are a few built-in low-level merge drivers defined that can be asked for via the merge attribute.

text
Usual 3-way file level merge for text files. Conflicted regions are marked with conflict markers
<<<<<<<, ======= and >>>>>>>. The version from your branch appears before the ======= marker, and the
version from the merged branch appears after the ======= marker.

binary
Keep the version from your branch in the work tree, but leave the path in the conflicted state for the

file) like this:

[merge "filfre"]
name = feel-free merge driver
driver = filfre %O %A %B
recursive = binary

The merge.*.name variable gives the driver a human-readable name.

The ‘merge.*.driver` variable’s value is used to construct a command to run to merge ancestor’s version
(%O), current version (%A) and the other branches’ version (%B). These three tokens are replaced with the
names of temporary files that hold the contents of these versions when the command line is built.
Additionally, %L will be replaced with the conflict marker size (see below).

The merge driver is expected to leave the result of the merge in the file named with %A by overwriting it,
and exit with zero status if it managed to merge them cleanly, or non-zero if there were conflicts.

The merge.*.recursive variable specifies what other merge driver to use when the merge driver is called
for an internal merge between common ancestors, when there are more than one. When left unspecified, the
driver itself is used for both internal merge and the final merge.

conflict-marker-size
This attribute controls the length of conflict markers left in the work tree file during a conflicted
merge. Only setting to the value to a positive integer has any meaningful effect.

For example, this line in .gitattributes can be used to tell the merge machinery to leave much longer
(instead of the usual 7-character-long) conflict markers when merging the file Documentation/git-merge.txt
results in a conflict.

Documentation/git-merge.txt conflict-marker-size=32

Checking whitespace errors
whitespace
The core.whitespace configuration variable allows you to define what diff and apply should consider
whitespace errors for all paths in the project (See git-config(1)). This attribute gives you finer control
per path.

Set
Notice all types of potential whitespace errors known to Git. The tab width is taken from the value of
the core.whitespace configuration variable.

Unset
Do not notice anything as error.

Unspecified
Use the value of the core.whitespace configuration variable to decide what to notice as error.

String
Specify a comma separate list of common whitespace problems to notice in the same format as the
core.whitespace configuration variable.

Creating an archive

Delta compression will not be attempted for blobs for paths with the attribute delta set to false.

Viewing files in GUI tools
encoding
The value of this attribute specifies the character encoding that should be used by GUI tools (e.g.
gitk(1) and git-gui(1)) to display the contents of the relevant file. Note that due to performance
considerations gitk(1) does not use this attribute unless you manually enable per-file encodings in its
options.

If this attribute is not set or has an invalid value, the value of the gui.encoding configuration variable
is used instead (See git-config(1)).

USING MACRO ATTRIBUTES
You do not want any end-of-line conversions applied to, nor textual diffs produced for, any binary file you
track. You would need to specify e.g.

*.jpg -text -diff

but that may become cumbersome, when you have many attributes. Using macro attributes, you can define an
attribute that, when set, also sets or unsets a number of other attributes at the same time. The system knows
a built-in macro attribute, binary:

*.jpg binary

Setting the "binary" attribute also unsets the "text" and "diff" attributes as above. Note that macro
attributes can only be "Set", though setting one might have the effect of setting or unsetting other
attributes or even returning other attributes to the "Unspecified" state.

DEFINING MACRO ATTRIBUTES
Custom macro attributes can be defined only in the .gitattributes file at the toplevel (i.e. not in any
subdirectory). The built-in macro attribute "binary" is equivalent to:

[attr]binary -diff -merge -text

EXAMPLE
If you have these three gitattributes file:

(in $GIT_DIR/info/attributes)

a* foo !bar -baz

(in .gitattributes)
abc foo bar baz

(in t/.gitattributes)
ab* merge=filfre
abc -foo -bar
*.c frotz

the attributes given to path t/abc are computed as follows:
As the result, the attributes assignment to t/abc becomes:

foo set to true
bar unspecified
baz set to false
merge set to string value "filfre"
frotz unspecified