SYNOPSIS
--------
-$GIT_DIR/info/attributes, gitattributes
+$GIT_DIR/info/attributes, .gitattributes
DESCRIPTION
Each line in `gitattributes` file is of form:
- glob attr1 attr2 ...
+ pattern attr1 attr2 ...
-That is, a glob pattern followed by an attributes list,
-separated by whitespaces. When the glob pattern matches the
+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.
Unspecified::
- No glob pattern matches the path, and nothing says if
+ 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 glob pattern matches the path, a later line
+When more than one pattern matches the path, a later line
overrides an earlier line. This overriding is done per
-attribute.
+attribute. The rules how the pattern matches paths are the
+same as in `.gitignore` files; see linkgit:gitignore[5].
When deciding what attributes are assigned to a path, git
consults `$GIT_DIR/info/attributes` file (which has the highest
precedence), `.gitattributes` file in the same directory as the
-path in question, and its parent directories (the further the
-directory that contains `.gitattributes` is from the path in
-question, the lower its precedence).
+path in question, and its parent directories up to the toplevel of the
+work tree (the further the directory that contains `.gitattributes`
+is from the path in question, the lower its precedence).
+
+If you wish to affect only a single repository (i.e., to assign
+attributes to files that are particular to one user's workflow), then
+attributes should be placed in the `$GIT_DIR/info/attributes` file.
+Attributes which should be version-controlled and distributed to other
+repositories (i.e., attributes of interest to all users) should go into
+`.gitattributes` files.
Sometimes you would need to override an setting of an attribute
for a path to `unspecified` state. This can be done by listing
-------
Certain operations by git can be influenced by assigning
-particular attributes to a path. Currently, three operations
-are attributes-aware.
+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
+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`.
+repository upon 'git-add' and 'git-commit'.
`crlf`
^^^^^^
Unset::
- Unsetting the `crlf` attribute on a path is meant to
- mark the path as a "binary" file. The path never goes
- through line endings conversion upon checkin/checkout.
+ Unsetting the `crlf` attribute on a path tells git not to
+ attempt any end-of-line conversion upon checkin or checkout.
Unspecified::
converted to LF upon checkin, but there is no conversion done
upon checkout.
+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...
-`ident`
-^^^^^^^
+- 'git-add' itself does not touch the files in the work tree, the
+ next checkout would, so the safety triggers;
-When the attribute `ident` is set to a path, git replaces
-`$ident$` in the blob object with `$ident:`, followed by
-40-character hexadecimal blob object name, followed by a dollar
-sign `$` upon checkout. Any byte sequence that begins with
-`$ident:` and ends with `$` in the worktree file is replaced
-with `$ident$` upon check-in.
+- '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;
+- '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.
-Interaction between checkin/checkout attributes
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-In the check-in codepath, the worktree file is first converted
-with `ident` (if specified), and then with `crlf` (again, if
-specified and applicable).
+`ident`
+^^^^^^^
-In the check-out codepath, the blob content is first converted
-with `crlf`, and then `ident`.
+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.
`filter`
^^^^^^^^
-A `filter` attribute can be set to a string value. This names
+A `filter` attribute can be set to a string value that names a
filter driver specified in the configuration.
-A filter driver consists of `clean` command and `smudge`
+A filter driver consists of a `clean` command and a `smudge`
command, either of which can be left unspecified. Upon
-checkout, when `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, `clean` command
-is used to convert the contents of worktree file upon checkin.
+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.
-Missing filter driver definition in the config is not an error
+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 keyword here is "more convenient" and not
-"turning something unusable into usable". In other words, it is
-"hanging yourself because we gave you a long rope" if your
-project uses filtering mechanism in such a way that it makes
-your project unusable unless the checkout is done with a
-specific filter in effect.
+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.
Interaction between checkin/checkout attributes
Generating diff text
~~~~~~~~~~~~~~~~~~~~
-The attribute `diff` affects if `git diff` generates textual
-patch for the path or just says `Binary files differ`.
+`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::
Unset::
A path to which the `diff` attribute is unset will
- generate `Binary files differ`.
+ generate `Binary files differ` (or a binary patch, if
+ binary patches are enabled).
Unspecified::
String::
- Diff is shown using the specified custom diff driver.
- The driver program is given its input using the same
- calling convention as used for GIT_EXTERNAL_DIFF
- program.
+ 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 a custom diff driver
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+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 a custom diff driver `jcdiff`, add a section to your
+To define an external diff driver `jcdiff`, add a section to your
`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
----------------------------------------------------------------
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 gitlink:git[7] for details.
+See linkgit:git[1] for details.
+
+
+Defining a custom hunk-header
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Each group of changes (called a "hunk") in the textual diff output
+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.
+
+------------------------
+*.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\\{.*)$"
+------------------------
+
+Note. A single level of backslashes are eaten by the
+configuration file parser, so you would need to double the
+backslashes; the pattern above picks a line that begins with a
+backslash, and zero or more occurrences of `sub` followed by
+`section` followed by open brace, to the end of line.
+
+There are a few built-in patterns to make this easier, and `tex`
+is one of them, so you do not have to write the above in your
+configuration file (you still need to enable this with the
+attribute mechanism, via `.gitattributes`). The following built in
+patterns are available:
+
+- `bibtex` suitable for files with BibTeX coded references.
+
+- `cpp` suitable for source code in the C and C++ languages.
+
+- `html` suitable for HTML/XHTML documents.
+
+- `java` suitable for source code in the Java language.
+
+- `objc` suitable for source code in the Objective-C language.
+
+- `pascal` suitable for source code in the Pascal/Delphi language.
+
+- `php` suitable for source code in the PHP language.
+
+- `python` suitable for source code in the Python language.
+
+- `ruby` suitable for source code in the Ruby language.
+
+- `tex` suitable for source code for LaTeX documents.
+
+
+Customizing word diff
+^^^^^^^^^^^^^^^^^^^^^
+
+You can customize the rules that `git diff --color-words` uses to
+split words in a line, by specifying an appropriate regular expression
+in the "diff.*.wordRegex" configuration variable. For example, in TeX
+a backslash followed by a sequence of letters forms a command, but
+several such commands can be run together without intervening
+whitespace. To separate them, use a regular expression in your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+------------------------
+[diff "tex"]
+ wordRegex = "\\\\[a-zA-Z]+|[{}]|\\\\.|[^\\{}[:space:]]+"
+------------------------
+
+A built-in pattern is provided for all languages listed in the
+previous section.
+
+
+Performing text diffs of binary files
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes it is desirable to see the diff of a text-converted
+version of some binary files. For example, a word processor
+document can be converted to an ASCII text representation, and
+the diff of the text shown. Even though this conversion loses
+some information, the resulting diff is useful for human
+viewing (but cannot be applied directly).
+
+The `textconv` config option is used to define a program for
+performing such a conversion. The program should take a single
+argument, the name of a file to convert, and produce the
+resulting text on stdout.
+
+For example, to show the diff of the exif information of a
+file instead of the binary information (assuming you have the
+exif tool installed), add the following section to your
+`$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.
Performing a three-way merge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+`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 programs 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`
+ contents in a way similar to 'merge' command of `RCS`
suite. This is suitable for ordinary text files.
Unset::
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 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.
+
+
Defining a custom merge driver
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The definition of a merge driver is done in `gitconfig` not
-`gitattributes` file, so strictly speaking this manual page is a
-wrong place to talk about it. However...
+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 `$HOME/.gitconfig` file) like this:
internal merge and the final merge.
+Checking whitespace errors
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+`whitespace`
+^^^^^^^^^^^^
+
+The `core.whitespace` configuration variable allows you to define what
+'diff' and 'apply' should consider whitespace errors for all paths in
+the project (See linkgit:git-config[1]). This attribute gives you finer
+control per path.
+
+Set::
+
+ Notice all types of potential whitespace errors known to git.
+
+Unset::
+
+ Do not notice anything as error.
+
+Unspecified::
+
+ Use the value of `core.whitespace` configuration variable to
+ decide what to notice as error.
+
+String::
+
+ Specify a comma separate list of common whitespace problems to
+ notice in the same format as `core.whitespace` configuration
+ variable.
+
+
+Creating an archive
+~~~~~~~~~~~~~~~~~~~
+
+`export-ignore`
+^^^^^^^^^^^^^^^
+
+Files and directories with the attribute `export-ignore` won't be added to
+archive files.
+
+`export-subst`
+^^^^^^^^^^^^^^
+
+If the attribute `export-subst` is set for a file then git will expand
+several placeholders when adding this file to an archive. The
+expansion depends on the availability of a commit ID, i.e., if
+linkgit:git-archive[1] has been given a tree instead of a commit or a
+tag then no replacement will be done. The placeholders are the same
+as those for the option `--pretty=format:` of linkgit:git-log[1],
+except that they need to be wrapped like this: `$Format:PLACEHOLDERS$`
+in the file. E.g. the string `$Format:%H$` will be replaced by the
+commit hash.
+
+
+Viewing files in GUI tools
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+`encoding`
+^^^^^^^^^^
+
+The value of this attribute specifies the character encoding that should
+be used by GUI tools (e.g. linkgit:gitk[1] and linkgit:git-gui[1]) to
+display the contents of the relevant file. Note that due to performance
+considerations linkgit: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 linkgit:git-config[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 specify e.g.
+
+------------
+*.jpg -crlf -diff
+------------
+
+but that may become cumbersome, when you have many attributes. Using
+attribute macros, you can specify groups of attributes set or unset at
+the same time. The system knows a built-in attribute macro, `binary`:
+
+------------
+*.jpg binary
+------------
+
+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 "crlf" 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:
+
+------------
+[attr]binary -diff -crlf
+------------
+
+
EXAMPLE
-------
the attributes given to path `t/abc` are computed as follows:
1. By examining `t/.gitattributes` (which is in the same
- diretory as the path in question), git finds that the first
+ 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.
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/gitattributes`. This file
+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 assignement to `t/abc` becomes:
+As the result, the attributes assignment to `t/abc` becomes:
----------------------------------------------------------------
foo set to true
----------------------------------------------------------------
+
GIT
---
-Part of the gitlink:git[7] suite
+Part of the linkgit:git[1] suite