GITATTRIBUTES(5)GITATTRIBUTES(5)NAMEgitattributes - 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 whites-
paces. 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 over-
rides an earlier line. This overriding is done per attribute.
The rules how the pattern matches paths are the same as in .git-
ignore files; see gitignore(5).
When deciding what attributes are assigned to a path, git
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GITATTRIBUTES(5)GITATTRIBUTES(5)
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).
If you wish to affect only a single repository (i.e., to assign
attributes to files that are particular to one user’s
workflow), then attributes should be placed in the
$GIT_DIR/info/attributes file. Attributes which should be ver-
sion-controlled and distributed to other repositories (i.e.,
attributes of interest to all users) should go into .gitat-
tributes files.
Sometimes you would need to override an setting of an attribute
for a path to unspecified state. This can be done by listing the
name of the attribute prefixed with an exclamation point !.
EFFECTS
Certain operations by git can be influenced by assigning particular
attributes to a path. Currently, the following operations are
attributes-aware.
Checking-out and checking-in
These attributes affect how the contents stored in the repository are
copied to the working tree files when commands such as git checkout and
git merge run. They also affect how git stores the contents you prepare
in the working tree in the repository upon git add and git commit.
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 normal-
ization and marks the path as a text file. End-of-line conver-
sion 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
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GITATTRIBUTES(5)GITATTRIBUTES(5)
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 con-
verted.
Any other value causes git to act as if text has been left
unspecified.
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.
For backwards compatibility, the crlf attribute is interpreted
as follows:
.ft C
crlf text
-crlf-text
crlf=input eol=lf
.ft
While git normally leaves file contents alone, it can be config-
ured 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.
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.ft C
*.txt text
*.vcproj eol=crlf
*.sh eol=lf
*.jpg -text
.ft
Other source code management systems normalize all text files in
their repositories, and there are two ways to enable similar
automatic normalization in git.
If you simply want to have CRLF line endings in your working
directory regardless of the repository you are working with, you
can set the config variable "core.autocrlf" without changing any
attributes.
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[core]
autocrlf = true
.ft
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.
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* text=auto
.ft
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
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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 reposi-
tory, 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:
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$ 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"
.ft
If any files that should not be normalized show up in git status, unset
their text attribute before running git add -u.
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manual.pdf -text
.ft
Conversely, text files that git does not detect can have normalization
enabled manually.
.ft C
weirdchars.txt text
.ft
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If core.safecrlf is set to "true" or "warn", git verifies if the con-
version 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...
o git add itself does not touch the files in the work tree, the next
checkout would, so the safety triggers;
o 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 does not trigger;
o git diff itself does not touch the files in the work tree, it is
often run to inspect the changes you intend to next git add. To
catch potential problems early, safety triggers.
When the attribute ident is set for a path, git replaces $Id$ in the
blob object with $Id:, followed by the 40-character hexadecimal blob
object name, followed by a dollar sign $ upon checkout. Any byte
sequence that begins with $Id: and ends with $ in the worktree file is
replaced with $Id$ upon check-in.
A filter attribute can be set to a string value that names a filter
driver specified in the configuration.
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 stan-
dard 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.
A missing filter driver definition in the config is not an error but
makes the filter a no-op passthru.
The content filtering is done to massage the content into a shape that
is more convenient for the platform, filesystem, and the user to use.
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.
For example, in .gitattributes, you would assign the filter attribute
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for paths.
.ft C
*.c filter=indent
.ft
Then you would define a "filter.indent.clean" and "fil-
ter.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").
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[filter "indent"]
clean = indent
smudge = cat
.ft
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.
In the check-in codepath, the worktree file is first converted with
filter driver (if specified and corresponding driver defined), then the
result is processed with ident (if specified), and then finally 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.
If you have added attributes to a file that cause the canonical reposi-
tory format for that file to change, such as adding a clean/smudge fil-
ter or text/eol/ident attributes, merging anything where the attribute
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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 configura-
tion 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
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 sec-
tion. The options for the diff driver "foo" are defined by the
configuration variables in the "diff.foo" section of the git
config file.
The definition of a diff driver is done in gitconfig, not gitat-
tributes file, so strictly speaking this manual page is a wrong
place to talk about it. However...
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To define an external diff driver jcdiff, add a section to your
$GIT_DIR/config file (or $HOME/.gitconfig file) like this:
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[diff "jcdiff"]
command = j-c-diff
.ft
When git needs to show you a diff for the path with diff
attribute set to jcdiff, it calls the command you specified with
the above configuration, i.e. j-c-diff, with 7 parameters, just
like GIT_EXTERNAL_DIFF program is called. See git(1) for
details.
Each group of changes (called a "hunk") in the textual diff out-
put is prefixed with a line of the form:
@@ -k,l +n,m @@ TEXT
This is called a hunk header. The "TEXT" portion is by default a
line that begins with an alphabet, an underscore or a dollar
sign; this matches what GNU diff -p output uses. This default
selection however is not suited for some contents, and you can
use a customized pattern to make a selection.
First, in .gitattributes, you would assign the diff attribute
for paths.
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*.tex diff=tex
.ft
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 $HOME/.gitconfig file) like this:
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[diff "tex"]
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xfuncname = "^(\\\\(sub)*section\\{.*)$"
.ft
Note. A single level of backslashes are eaten by the configura-
tion 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:
o bibtex suitable for files with BibTeX coded references.
o cpp suitable for source code in the C and C++ languages.
o csharp suitable for source code in the C# language.
o fortran suitable for source code in the Fortran language.
o html suitable for HTML/XHTML documents.
o java suitable for source code in the Java language.
o objc suitable for source code in the Objective-C language.
o pascal suitable for source code in the Pascal/Delphi language.
o php suitable for source code in the PHP language.
o python suitable for source code in the Python language.
o ruby suitable for source code in the Ruby language.
o tex suitable for source code for LaTeX documents.
You can customize the rules that git diff --word-diff uses to split
words in a line, by specifying an appropriate regular expression in the
"diff.*.wordRegex" configuration variable. For example, in TeX a back-
slash followed by a sequence of letters forms a command, but several
such commands can be run together without intervening whitespace. To
separate them, use a regular expression in your $GIT_DIR/config file
(or $HOME/.gitconfig file) like this:
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.ft C
[diff "tex"]
wordRegex = "\\\\[a-zA-Z]+|[{}]|\\\\.|[^\\{}[:space:]]+"
.ft
A built-in pattern is provided for all languages listed in the previous
section.
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 result-
ing 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/.git-
config file):
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[diff "jpg"]
textconv = exif
.ft
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.
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Because text conversion can be slow, especially when doing a large num-
ber of them with git log -p, git provides a mechanism to cache the out-
put and use it in future diffs. To enable caching, set the
"cachetextconv" variable in your diff driver’s config. For exam-
ple:
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[diff "jpg"]
textconv = exif
cachetextconv = true
.ft
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 fil-
ter. 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).
Performing a three-way merge
The attribute merge affects how three versions of a file is 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 suit-
able for binary files that does not have a well-defined merge
semantics.
Unspecified
By default, this uses the same built-in 3-way merge driver as is
the case the merge attribute is set. However, merge.default con-
figuration variable can name different merge driver to be used
for paths to 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 speci-
fied by asking for "text" driver; the built-in "take the current
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branch" driver can be requested with "binary".
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 user to sort out.
union Run 3-way file level merge for text files, but take lines from
both versions, instead of leaving conflict markers. This tends
to leave the added lines in the resulting file in random order
and the user should verify the result. Do not use this if you do
not understand the implications.
The definition of a merge driver is done in the .git/config
file, not in the gitattributes file, so strictly speaking this
manual page is a wrong place to talk about it. However...
To define a custom merge driver filfre, add a section to your
$GIT_DIR/config file (or $HOME/.gitconfig file) like this:
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[merge "filfre"]
name = feel-free merge driver
driver = filfre %O %A %B
recursive = binary
.ft
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 tempo-
rary files that hold the contents of these versions when the
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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.
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 Docu-
mentation/git-merge.txt results in a conflict.
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Documentation/git-merge.txt conflict-marker-size=32
.ft
Checking whitespace errors
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.
Unset Do not notice anything as error.
Unspecified
Use the value of core.whitespace configuration variable to
decide what to notice as error.
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String Specify a comma separate list of common whitespace problems to
notice in the same format as core.whitespace configuration vari-
able.
Creating an archive
Files and directories with the attribute export-ignore won’t be
added to archive files.
If the attribute export-subst is set for a file then git will expand
several placeholders when adding this file to an archive. The expansion
depends on the availability of a commit ID, i.e., if git-archive(1) has
been given a tree instead of a commit or a tag then no replacement will
be done. The placeholders are the same as those for the option
--pretty=format: of git-log(1), except that they need to be wrapped
like this: $Format:PLACEHOLDERS$ in the file. E.g. the string $For-
mat:%H$ will be replaced by the commit hash.
Packing objects
Delta compression will not be attempted for blobs for paths with the
attribute delta set to false.
Viewing files in GUI tools
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 consid-
erations 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-con-
fig(1)).
USING ATTRIBUTE MACROS
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 spec-
ify e.g.
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*.jpg -text -diff
.ft
but that may become cumbersome, when you have many attributes. Using
attribute macros, you can specify groups of attributes set or unset at
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the same time. The system knows a built-in attribute macro, binary:
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*.jpg binary
.ft
which is equivalent to the above. Note that the attribute macros can
only be "Set" (see the above example that sets "binary" macro as if it
were an ordinary attribute --- setting it in turn unsets "text" and
"diff").
DEFINING ATTRIBUTE MACROS
Custom attribute macros can be defined only in the .gitattributes file
at the toplevel (i.e. not in any subdirectory). The built-in attribute
macro "binary" is equivalent to:
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[attr]binary -diff -text
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EXAMPLE
If you have these three gitattributes file:
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(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
.ft
the attributes given to path t/abc are computed as follows:
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1. By examining t/.gitattributes (which is in the same directory as the
path in question), git finds that the first line matches. merge
attribute is set. It also finds that the second line matches, and
attributes foo and bar are unset.
2. Then it examines .gitattributes (which is in the parent directory),
and finds that the first line matches, but t/.gitattributes file
already decided how merge, foo and bar attributes should be given to
this path, so it leaves foo and bar unset. Attribute baz is set.
3. Finally it examines $GIT_DIR/info/attributes. This file is used to
override the in-tree settings. The first line is a match, and foo is
set, bar is reverted to unspecified state, and baz is unset.
As the result, the attributes assignment to t/abc becomes:
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foo set to true
bar unspecified
baz set to false
merge set to string value "filfre"
frotz unspecified
.ft
GIT
Part of the git(1) suite
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