определение атрибутов для каждого пути (Defining attributes per path)
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
switch, 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.
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. Note that setting
core.autocrlf to true or input overrides core.eol (see the
definitions of those options in git-config(1)).
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 conversion. If Git decides that the
content is text, its line endings are converted to LF on
checkin. When the file has been committed with CRLF, no
conversion is done.
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 conversion
without any content checks, effectively setting the text
attribute. Note that setting this attribute on paths which
are in the index with CRLF line endings may make the paths to
be considered dirty. Adding the path to the index again will
normalize the line endings in the index.
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.
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 using
any attributes.
[core]
autocrlf = true
This does not force normalization of 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 ensure that text files that any contributor
introduces to the repository have their line endings
normalized, you can set the text attribute to "auto" for all
files.
* text=auto
The attributes allow a fine-grained control, how the line
endings are converted. 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.
* text=auto
*.txt text
*.vcproj text eol=crlf
*.sh text eol=lf
*.jpg -text
Note
When text=auto conversion is enabled in a cross-platform
project using push and pull to a central repository the
text files containing CRLFs should be normalized.
From a clean working directory:
$ echo "* text=auto" >.gitattributes
$ git add --renormalize .
$ git status # Show files that will be normalized
$ 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 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.
working-tree-encoding
Git recognizes files encoded in ASCII or one of its supersets
(e.g. UTF-8, ISO-8859-1, ...) as text files. Files encoded in
certain other encodings (e.g. UTF-16) are interpreted as
binary and consequently built-in Git text processing tools
(e.g. git diff) as well as most Git web front ends do not
visualize the contents of these files by default.
In these cases you can tell Git the encoding of a file in the
working directory with the working-tree-encoding attribute.
If a file with this attribute is added to Git, then Git
re-encodes the content from the specified encoding to UTF-8.
Finally, Git stores the UTF-8 encoded content in its internal
data structure (called "the index"). On checkout the content
is re-encoded back to the specified encoding.
Please note that using the working-tree-encoding attribute
may have a number of pitfalls:
• Alternative Git implementations (e.g. JGit or libgit2)
and older Git versions (as of March 2018) do not support
the working-tree-encoding attribute. If you decide to use
the working-tree-encoding attribute in your repository,
then it is strongly recommended to ensure that all
clients working with the repository support it.
For example, Microsoft Visual Studio resources files
(*.rc) or PowerShell script files (*.ps1) are sometimes
encoded in UTF-16. If you declare *.ps1 as files as
UTF-16 and you add foo.ps1 with a working-tree-encoding
enabled Git client, then foo.ps1 will be stored as UTF-8
internally. A client without working-tree-encoding
support will checkout foo.ps1 as UTF-8 encoded file. This
will typically cause trouble for the users of this file.
If a Git client that does not support the
working-tree-encoding attribute adds a new file bar.ps1,
then bar.ps1 will be stored "as-is" internally (in this
example probably as UTF-16). A client with
working-tree-encoding support will interpret the internal
contents as UTF-8 and try to convert it to UTF-16 on
checkout. That operation will fail and cause an error.
• Reencoding content to non-UTF encodings can cause errors
as the conversion might not be UTF-8 round trip safe. If
you suspect your encoding to not be round trip safe, then
add it to core.checkRoundtripEncoding to make Git check
the round trip encoding (see git-config(1)). SHIFT-JIS
(Japanese character set) is known to have round trip
issues with UTF-8 and is checked by default.
• Reencoding content requires resources that might slow
down certain Git operations (e.g git checkout or git
add).
Use the working-tree-encoding attribute only if you cannot
store a file in UTF-8 encoding and if you want Git to be able
to process the content as text.
As an example, use the following attributes if your *.ps1
files are UTF-16 encoded with byte order mark (BOM) and you
want Git to perform automatic line ending conversion based on
your platform.
*.ps1 text working-tree-encoding=UTF-16
Use the following attributes if your *.ps1 files are UTF-16
little endian encoded without BOM and you want Git to use
Windows line endings in the working directory (use
UTF-16LE-BOM instead of UTF-16LE if you want UTF-16 little
endian with BOM). Please note, it is highly recommended to
explicitly define the line endings with eol if the
working-tree-encoding attribute is used to avoid ambiguity.
*.ps1 text working-tree-encoding=UTF-16LE eol=CRLF
You can get a list of all available encodings on your
platform with the following command:
iconv --list
If you do not know the encoding of a file, then you can use
the file command to guess the encoding:
file foo.ps1
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 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 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. By default these commands
process only a single blob and terminate. If a long running
process filter is used in place of clean and/or smudge
filters, then Git can process all blobs with a single filter
command invocation for the entire life of a single Git
command, for example git add --all. If a long running process
filter is configured then it always takes precedence over a
configured single blob filter. See section below for the
description of the protocol used to communicate with a
process filter.
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.
Note: Whenever the clean filter is changed, the repo should
be renormalized: $ git add --renormalize .
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
Sequence "%f" on the filter command line is replaced with the
name of the file the filter is working on. A filter might use
this in keyword substitution. For example:
[filter "p4"]
clean = git-p4-filter --clean %f
smudge = git-p4-filter --smudge %f
Note that "%f" is the name of the path that is being worked
on. Depending on the version that is being filtered, the
corresponding file on disk may not exist, or may have
different contents. So, smudge and clean commands should not
try to access the file on disk, but only act as filters on
the content provided to them on standard input.
Long Running Filter Process
If the filter command (a string value) is defined via
filter.<driver>.process then Git can process all blobs with a
single filter invocation for the entire life of a single Git
command. This is achieved by using the long-running process
protocol (described in
technical/long-running-process-protocol.txt).
When Git encounters the first file that needs to be cleaned
or smudged, it starts the filter and performs the handshake.
In the handshake, the welcome message sent by Git is
"git-filter-client", only version 2 is supported, and the
supported capabilities are "clean", "smudge", and "delay".
Afterwards Git sends a list of "key=value" pairs terminated
with a flush packet. The list will contain at least the
filter command (based on the supported capabilities) and the
pathname of the file to filter relative to the repository
root. Right after the flush packet Git sends the content
split in zero or more pkt-line packets and a flush packet to
terminate content. Please note, that the filter must not send
any response before it received the content and the final
flush packet. Also note that the "value" of a "key=value"
pair can contain the "=" character whereas the key would
never contain that character.
packet: git> command=smudge
packet: git> pathname=path/testfile.dat
packet: git> 0000
packet: git> CONTENT
packet: git> 0000
The filter is expected to respond with a list of "key=value"
pairs terminated with a flush packet. If the filter does not
experience problems then the list must contain a "success"
status. Right after these packets the filter is expected to
send the content in zero or more pkt-line packets and a flush
packet at the end. Finally, a second list of "key=value"
pairs terminated with a flush packet is expected. The filter
can change the status in the second list or keep the status
as is with an empty list. Please note that the empty list
must be terminated with a flush packet regardless.
packet: git< status=success
packet: git< 0000
packet: git< SMUDGED_CONTENT
packet: git< 0000
packet: git< 0000 # empty list, keep "status=success" unchanged!
If the result content is empty then the filter is expected to
respond with a "success" status and a flush packet to signal
the empty content.
packet: git< status=success
packet: git< 0000
packet: git< 0000 # empty content!
packet: git< 0000 # empty list, keep "status=success" unchanged!
In case the filter cannot or does not want to process the
content, it is expected to respond with an "error" status.
packet: git< status=error
packet: git< 0000
If the filter experiences an error during processing, then it
can send the status "error" after the content was (partially
or completely) sent.
packet: git< status=success
packet: git< 0000
packet: git< HALF_WRITTEN_ERRONEOUS_CONTENT
packet: git< 0000
packet: git< status=error
packet: git< 0000
In case the filter cannot or does not want to process the
content as well as any future content for the lifetime of the
Git process, then it is expected to respond with an "abort"
status at any point in the protocol.
packet: git< status=abort
packet: git< 0000
Git neither stops nor restarts the filter process in case the
"error"/"abort" status is set. However, Git sets its exit
code according to the filter.<driver>.required flag,
mimicking the behavior of the filter.<driver>.clean /
filter.<driver>.smudge mechanism.
If the filter dies during the communication or does not
adhere to the protocol then Git will stop the filter process
and restart it with the next file that needs to be processed.
Depending on the filter.<driver>.required flag Git will
interpret that as error.
Delay
If the filter supports the "delay" capability, then Git can
send the flag "can-delay" after the filter command and
pathname. This flag denotes that the filter can delay
filtering the current blob (e.g. to compensate network
latencies) by responding with no content but with the status
"delayed" and a flush packet.
packet: git> command=smudge
packet: git> pathname=path/testfile.dat
packet: git> can-delay=1
packet: git> 0000
packet: git> CONTENT
packet: git> 0000
packet: git< status=delayed
packet: git< 0000
If the filter supports the "delay" capability then it must
support the "list_available_blobs" command. If Git sends this
command, then the filter is expected to return a list of
pathnames representing blobs that have been delayed earlier
and are now available. The list must be terminated with a
flush packet followed by a "success" status that is also
terminated with a flush packet. If no blobs for the delayed
paths are available, yet, then the filter is expected to
block the response until at least one blob becomes available.
The filter can tell Git that it has no more delayed blobs by
sending an empty list. As soon as the filter responds with an
empty list, Git stops asking. All blobs that Git has not
received at this point are considered missing and will result
in an error.
packet: git> command=list_available_blobs
packet: git> 0000
packet: git< pathname=path/testfile.dat
packet: git< pathname=path/otherfile.dat
packet: git< 0000
packet: git< status=success
packet: git< 0000
After Git received the pathnames, it will request the
corresponding blobs again. These requests contain a pathname
and an empty content section. The filter is expected to
respond with the smudged content in the usual way as
explained above.
packet: git> command=smudge
packet: git> pathname=path/testfile.dat
packet: git> 0000
packet: git> 0000 # empty content!
packet: git< status=success
packet: git< 0000
packet: git< SMUDGED_CONTENT
packet: git< 0000
packet: git< 0000 # empty list, keep "status=success" unchanged!
Example
A long running filter demo implementation can be found in
contrib/long-running-filter/example.pl located in the Git
core repository. If you develop your own long running filter
process then the GIT_TRACE_PACKET environment variables can
be very helpful for debugging (see git(1)).
Please note that you cannot use an existing
filter.<driver>.clean or filter.<driver>.smudge command with
filter.<driver>.process because the former two use a
different inter process communication protocol than the
latter one.
Interaction between checkin/checkout attributes
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.
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
and is smaller than core.bigFileThreshold, 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
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.
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:
• ada suitable for source code in the Ada language.
• bash suitable for source code in the Bourne-Again SHell
language. Covers a superset of POSIX shell function
definitions.
• 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.
• css suitable for cascading style sheets.
• dts suitable for devicetree (DTS) files.
• elixir suitable for source code in the Elixir language.
• fortran suitable for source code in the Fortran language.
• fountain suitable for Fountain documents.
• golang suitable for source code in the Go language.
• html suitable for HTML/XHTML documents.
• java suitable for source code in the Java language.
• markdown suitable for Markdown documents.
• matlab suitable for source code in the MATLAB and Octave
languages.
• 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.
• rust suitable for source code in the Rust language.
• scheme suitable for source code in the Scheme 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 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.
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 your own
diff. In many cases, existing programs can be used as
textconv filters (e.g., exif, odt2txt).
2. Git diff features. By performing only the transformation
step yourself, you can still utilize many of Git's diff
features, including colorization, word-diff, and combined
diffs for merges.
3. Caching. Textconv caching can speed up repeated diffs,
such as those you might trigger by running git log -p.
Marking files as binary
Git usually guesses correctly whether a blob contains text or
binary data by examining the beginning of the contents.
However, sometimes you may want to override its decision,
either because a blob contains binary data later in the file,
or because the content, while technically composed of text
characters, is 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 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 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:
[merge "filfre"]
name = feel-free merge driver
driver = filfre %O %A %B %L %P
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.
The merge driver can learn the pathname in which the merged
result will be stored via placeholder %P.
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
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 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 $Format:%H$ will be replaced by the commit hash.
However, only one %(describe) placeholder is expanded per
archive to avoid denial-of-service attacks.
Packing objects
delta
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)).
