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diff --git a/third_party/git/Documentation/gitattributes.txt b/third_party/git/Documentation/gitattributes.txt deleted file mode 100644 index 2d0a03715be6..000000000000 --- a/third_party/git/Documentation/gitattributes.txt +++ /dev/null @@ -1,1300 +0,0 @@ -gitattributes(5) -================ - -NAME ----- -gitattributes - Defining attributes per path - -SYNOPSIS --------- -$GIT_DIR/info/attributes, .gitattributes - - -DESCRIPTION ------------ - -A `gitattributes` file is a simple text file that gives -`attributes` to pathnames. - -Each line in `gitattributes` file is of form: - - pattern attr1 attr2 ... - -That is, a pattern followed by an attributes list, -separated by whitespaces. Leading and trailing whitespaces are -ignored. Lines that begin with '#' are ignored. Patterns -that begin with a double quote are quoted in C style. -When the pattern matches the path in question, the attributes -listed on the line are given to the path. - -Each attribute can be in one of these states for a given path: - -Set:: - - The path has the attribute with special value "true"; - this is specified by listing only the name of the - attribute in the attribute list. - -Unset:: - - The path has the attribute with special value "false"; - this is specified by listing the name of the attribute - prefixed with a dash `-` in the attribute list. - -Set to a value:: - - The path has the attribute with specified string value; - this is specified by listing the name of the attribute - followed by an equal sign `=` and its value in the - attribute list. - -Unspecified:: - - No pattern matches the path, and nothing says if - the path has or does not have the attribute, the - attribute for the path is said to be Unspecified. - -When more than one pattern matches the path, a later line -overrides an earlier line. This overriding is done per -attribute. - -The rules by which the pattern matches paths are the same as in -`.gitignore` files (see linkgit:gitignore[5]), with a few exceptions: - - - negative patterns are forbidden - - - patterns that match a directory do not recursively match paths - inside that directory (so using the trailing-slash `path/` syntax is - pointless in an attributes file; use `path/**` instead) - -When deciding what attributes are assigned to a path, Git -consults `$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 linkgit: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. - -Sometimes you would need to override a 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 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 -linkgit: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 linkgit: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 linkgit: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 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: - -- `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. - -- `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. - -- `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 linkgit: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 -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$` will be replaced by the -commit hash. - - -Packing objects -~~~~~~~~~~~~~~~ - -`delta` -^^^^^^^ - -Delta compression will not be attempted for blobs for paths with the -attribute `delta` set to false. - - -Viewing files in GUI tools -~~~~~~~~~~~~~~~~~~~~~~~~~~ - -`encoding` -^^^^^^^^^^ - -The value of this attribute specifies the character encoding that should -be used by GUI tools (e.g. linkgit:gitk[1] and linkgit:git-gui[1]) to -display the contents of the relevant file. Note that due to performance -considerations linkgit:gitk[1] does not use this attribute unless you -manually enable per-file encodings in its options. - -If this attribute is not set or has an invalid value, the value of the -`gui.encoding` configuration variable is used instead -(See linkgit:git-config[1]). - - -USING MACRO ATTRIBUTES ----------------------- - -You do not want any end-of-line conversions applied to, nor textual diffs -produced for, any binary file you track. You would need to specify e.g. - ------------- -*.jpg -text -diff ------------- - -but that may become cumbersome, when you have many attributes. Using -macro attributes, you can define an attribute that, when set, also -sets or unsets a number of other attributes at the same time. The -system knows a built-in macro attribute, `binary`: - ------------- -*.jpg binary ------------- - -Setting the "binary" attribute also unsets the "text" and "diff" -attributes as above. Note that macro attributes can only be "Set", -though setting one might have the effect of setting or unsetting other -attributes or even returning other attributes to the "Unspecified" -state. - - -DEFINING MACRO ATTRIBUTES -------------------------- - -Custom macro attributes can be defined only in top-level gitattributes -files (`$GIT_DIR/info/attributes`, the `.gitattributes` file at the -top level of the working tree, or the global or system-wide -gitattributes files), not in `.gitattributes` files in working tree -subdirectories. The built-in macro attribute "binary" is equivalent -to: - ------------- -[attr]binary -diff -merge -text ------------- - - -EXAMPLES --------- - -If you have these three `gitattributes` file: - ----------------------------------------------------------------- -(in $GIT_DIR/info/attributes) - -a* foo !bar -baz - -(in .gitattributes) -abc foo bar baz - -(in t/.gitattributes) -ab* merge=filfre -abc -foo -bar -*.c frotz ----------------------------------------------------------------- - -the attributes given to path `t/abc` are computed as follows: - -1. By examining `t/.gitattributes` (which is in the same - directory as the path in question), Git finds that the first - line matches. `merge` attribute is set. It also finds that - the second line matches, and attributes `foo` and `bar` - are unset. - -2. Then it examines `.gitattributes` (which is in the parent - directory), and finds that the first line matches, but - `t/.gitattributes` file already decided how `merge`, `foo` - and `bar` attributes should be given to this path, so it - leaves `foo` and `bar` unset. Attribute `baz` is set. - -3. Finally it examines `$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: - ----------------------------------------------------------------- -foo set to true -bar unspecified -baz set to false -merge set to string value "filfre" -frotz unspecified ----------------------------------------------------------------- - - -SEE ALSO --------- -linkgit:git-check-attr[1]. - -GIT ---- -Part of the linkgit:git[1] suite |