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diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt index 46f9d591aa..80120ea14f 100644 --- a/Documentation/gitattributes.txt +++ b/Documentation/gitattributes.txt @@ -7,7 +7,7 @@ gitattributes - defining attributes per path SYNOPSIS -------- -$GIT_DIR/info/attributes, gitattributes +$GIT_DIR/info/attributes, .gitattributes DESCRIPTION @@ -18,10 +18,10 @@ A `gitattributes` file is a simple text file that gives 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. @@ -48,23 +48,38 @@ Set to a value:: 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 `$GIT_DIR/info/attributes` file (which has the highest precedence), `.gitattributes` file in the same directory as the -path in question, and its parent directories (the further the -directory that contains `.gitattributes` is from the path in -question, the lower its precedence). +path in question, and its parent directories up to the toplevel of the +work tree (the further the directory that contains `.gitattributes` +is from the path in question, the lower its precedence). Finally +global and system-wide files are considered (they have the lowest +precedence). + +If you wish to affect only a single repository (i.e., to assign +attributes to files that are particular to +one user's workflow for that repository), then +attributes should be placed in the `$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]). +Attributes for all users on a system should be placed in the +`$(prefix)/etc/gitattributes` file. Sometimes you would need to override an setting of an attribute -for a path to `unspecified` state. This can be done by listing +for a path to `Unspecified` state. This can be done by listing the name of the attribute prefixed with an exclamation point `!`. @@ -80,106 +95,276 @@ 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` +`text` ^^^^^^ -This attribute controls the line-ending convention. +This attribute enables and controls end-of-line normalization. When a +text file is normalized, its line endings are converted to LF in the +repository. To control what line ending style is used in the working +directory, use the `eol` attribute for a single file and the +`core.eol` configuration variable for all text files. Set:: - Setting the `crlf` attribute on a path is meant to mark - the path as a "text" file. 'core.autocrlf' conversion - takes place without guessing the content type by - inspection. + 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 `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 `text` attribute on a path tells git not to + attempt any end-of-line conversion upon checkin or checkout. + +Set to string value "auto":: + + When `text` is set to "auto", the path is marked for automatic + end-of-line normalization. If git decides that the content is + text, its line endings are normalized to LF on checkin. Unspecified:: - Unspecified `crlf` attribute tells git to apply the - `core.autocrlf` conversion when the file content looks - like text. + If the `text` attribute is unspecified, git uses the + `core.autocrlf` configuration variable to determine if the + file should be converted. -Set to string value "input":: +Any other value causes git to act as if `text` has been left +unspecified. - This is similar to setting the attribute to `true`, but - also forces git to act as if `core.autocrlf` is set to - `input` for the path. +`eol` +^^^^^ -Any other value set to `crlf` attribute is ignored and git acts -as if the attribute is left unspecified. +This attribute sets a specific line-ending style to be used in the +working directory. It enables end-of-line normalization without any +content checks, effectively setting the `text` attribute. +Set to string value "crlf":: -The `core.autocrlf` conversion -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + 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 the configuration variable `core.autocrlf` is false, no -conversion is done. +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. -When `core.autocrlf` is true, it means that the platform wants -CRLF line endings for files in the working tree, and you want to -convert them back to the normal LF line endings when checking -in to the repository. +------------------------ +*.txt text +*.vcproj eol=crlf +*.sh eol=lf +*.jpg -text +------------------------ + +Other source code management systems normalize all text files in their +repositories, and there are two ways to enable similar automatic +normalization in git. + +If you simply want to have CRLF line endings in your working directory +regardless of the repository you are working with, you can set the +config variable "core.autocrlf" without changing any attributes. + +------------------------ +[core] + autocrlf = true +------------------------ + +This does not force normalization of all text files, but does ensure +that text files that you introduce to the repository have their line +endings normalized to LF when they are added, and that files that are +already normalized in the repository stay normalized. + +If you want to interoperate with a source code management system that +enforces end-of-line normalization, or you simply want all text files +in your repository to be normalized, you should instead set the `text` +attribute to "auto" for _all_ files. -When `core.autocrlf` is set to "input", line endings are -converted to LF upon checkin, but there is no conversion done -upon checkout. +------------------------ +* text=auto +------------------------ + +This ensures that all files that git considers to be text will have +normalized (LF) line endings in the repository. The `core.eol` +configuration variable controls which line endings git will use for +normalized files in your working directory; the default is to use the +native line ending for your platform, or CRLF if `core.autocrlf` is +set. + +NOTE: When `text=auto` normalization is enabled in an existing +repository, any text files containing CRLFs should be normalized. If +they are not they will be normalized the next time someone tries to +change them, causing unfortunate misattribution. From a clean working +directory: + +------------------------------------------------- +$ echo "* text=auto" >>.gitattributes +$ rm .git/index # Remove the index to force git to +$ git reset # re-scan the working directory +$ git status # Show files that will be normalized +$ git add -u +$ git add .gitattributes +$ git commit -m "Introduce end-of-line normalization" +------------------------------------------------- + +If any files that should not be normalized show up in 'git status', +unset their `text` attribute before running 'git add -u'. + +------------------------ +manual.pdf -text +------------------------ + +Conversely, text files that git does not detect can have normalization +enabled manually. + +------------------------ +weirdchars.txt text +------------------------ + +If `core.safecrlf` is set to "true" or "warn", git verifies if +the conversion is reversible for the current setting of +`core.autocrlf`. For "true", git rejects irreversible +conversions; for "warn", git only prints a warning but accepts +an irreversible conversion. The safety triggers to prevent such +a conversion done to the files in the work tree, but there are a +few exceptions. Even though... + +- 'git add' itself does not touch the files in the work tree, the + next checkout would, so the safety triggers; + +- 'git apply' to update a text file with a patch does touch the files + in the work tree, but the operation is about text files and CRLF + conversion is about fixing the line ending inconsistencies, so the + safety 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. `ident` ^^^^^^^ -When the attribute `ident` is set to a path, git replaces -`$Id$` in the blob object with `$Id:`, followed by +When the attribute `ident` is set for a path, git replaces +`$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. -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). - -In the check-out codepath, the blob content is first converted -with `crlf`, and then `ident`. - - `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. + +One use of the content filtering is to massage the content into a shape +that is more convenient for the platform, filesystem, and the user to use. +For this mode of operation, the key phrase here is "more convenient" and +not "turning something unusable into usable". In other words, the intent +is that if someone unsets the filter driver definition, or does not have +the appropriate filter program, the project should still be usable. + +Another use of the content filtering is to store the content that cannot +be directly used in the repository (e.g. a UUID that refers to the true +content stored outside git, or an encrypted content) and turn it into a +usable form upon checkout (e.g. download the external content, or decrypt +the encrypted content). + +These two filters behave differently, and by default, a filter is taken as +the former, massaging the contents into more convenient shape. A missing +filter driver definition in the config, or a filter driver that exits with +a non-zero status, is not an error but makes the filter a no-op passthru. + +You can declare that a filter turns a content that by itself is unusable +into a usable content by setting the filter.<driver>.required configuration +variable to `true`. + +For example, in .gitattributes, you would assign the `filter` +attribute for paths. + +------------------------ +*.c filter=indent +------------------------ + +Then you would define a "filter.indent.clean" and "filter.indent.smudge" +configuration in your .git/config to specify a pair of commands to +modify the contents of C programs when the source files are checked +in ("clean" is run) and checked out (no change is made because the +command is "cat"). -Missing filter driver definition in the config is not an error -but makes the filter a no-op passthru. +------------------------ +[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: -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. +------------------------ +[filter "p4"] + clean = git-p4-filter --clean %f + smudge = git-p4-filter --smudge %f +------------------------ Interaction between checkin/checkout attributes @@ -188,20 +373,48 @@ 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 `crlf` (again, if specified +specified), and then finally with `text` (again, if specified and applicable). In the check-out codepath, the blob content is first converted -with `crlf`, and then `ident` and fed to `filter`. +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 ~~~~~~~~~~~~~~~~~~~~ -The attribute `diff` affects if `git diff` generates textual -patch for the path or just says `Binary files differ`. It also -can affect what line is shown on the hunk header `@@ -k,l +n,m @@` -line. +`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:: @@ -212,7 +425,8 @@ 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:: @@ -223,21 +437,21 @@ 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. This name is also used for custom hunk header - selection. + 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 `$HOME/.gitconfig` file) like this: ---------------------------------------------------------------- @@ -249,37 +463,38 @@ When git needs to show you a diff for the path with `diff` attribute set to `jcdiff`, it calls the command you specified with the above configuration, i.e. `j-c-diff`, with 7 parameters, just like `GIT_EXTERNAL_DIFF` program is called. -See gitlink:git[7] for details. +See linkgit:git[1] for details. Defining a custom hunk-header ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -Each group of changes (called "hunk") in the textual diff output +Each group of changes (called a "hunk") in the textual diff output is prefixed with a line of the form: @@ -k,l +n,m @@ TEXT -The text is called 'hunk header', and by default a line that -begins with an alphabet, an underscore or a dollar sign is used, -which matches what GNU `diff -p` output uses. This default -selection however is not suited for some contents, and you can -use customized pattern to make a selection. +This is called a 'hunk header'. The "TEXT" portion is by default a line +that begins with an alphabet, an underscore or a dollar sign; this +matches what GNU 'diff -p' output uses. This default selection however +is not suited for some contents, and you can use a customized pattern +to make a selection. -First in .gitattributes, you would assign the `diff` attribute +First, in .gitattributes, you would assign the `diff` attribute for paths. ------------------------ *.tex diff=tex ------------------------ -Then, you would define "diff.tex.funcname" configuration to +Then, you would define a "diff.tex.xfuncname" configuration to specify a regular expression that matches a line that you would -want to appear as the hunk header, like this: +want to appear as the hunk header "TEXT". Add a section to your +`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: ------------------------ [diff "tex"] - funcname = "^\\(\\\\\\(sub\\)*section{.*\\)$" + xfuncname = "^(\\\\(sub)*section\\{.*)$" ------------------------ Note. A single level of backslashes are eaten by the @@ -291,37 +506,209 @@ backslash, and zero or more occurrences of `sub` followed by There are a few built-in patterns to make this easier, and `tex` is one of them, so you do not have to write the above in your configuration file (you still need to enable this with the -attribute mechanism, via `.gitattributes`). Another built-in -pattern is defined for `java` that defines a pattern suitable -for program text in Java language. +attribute mechanism, via `.gitattributes`). The following built in +patterns are available: + +- `bibtex` suitable for files with BibTeX coded references. + +- `cpp` suitable for source code in the C and C++ languages. + +- `csharp` suitable for source code in the C# language. + +- `fortran` suitable for source code in the Fortran language. + +- `html` suitable for HTML/XHTML documents. + +- `java` suitable for source code in the Java language. + +- `matlab` suitable for source code in the MATLAB language. + +- `objc` suitable for source code in the Objective-C language. + +- `pascal` suitable for source code in the Pascal/Delphi language. + +- `perl` suitable for source code in the Perl language. + +- `php` suitable for source code in the PHP language. + +- `python` suitable for source code in the Python language. + +- `ruby` suitable for source code in the Ruby language. + +- `tex` suitable for source code for LaTeX documents. + + +Customizing word diff +^^^^^^^^^^^^^^^^^^^^^ + +You can customize the rules that `git diff --word-diff` uses to +split words in a line, by specifying an appropriate regular expression +in the "diff.*.wordRegex" configuration variable. For example, in TeX +a backslash followed by a sequence of letters forms a command, but +several such commands can be run together without intervening +whitespace. To separate them, use a regular expression in your +`$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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -The attribute `merge` affects how three versions of a file is +`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 programs such as `git revert` and `git cherry-pick`. +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` + 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 does + 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 the `merge` attribute is set. - However, `merge.default` configuration variable can name - different merge driver to be used for paths to which the + 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:: @@ -333,12 +720,43 @@ String:: 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: @@ -358,7 +776,8 @@ 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. +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 @@ -372,6 +791,144 @@ When left unspecified, the driver itself is used for both internal merge and the final merge. +`conflict-marker-size` +^^^^^^^^^^^^^^^^^^^^^^ + +This attribute controls the length of conflict markers left in +the work tree file during a conflicted merge. Only setting to +the value to a positive integer has any meaningful effect. + +For example, this line in `.gitattributes` can be used to tell the merge +machinery to leave much longer (instead of the usual 7-character-long) +conflict markers when merging the file `Documentation/git-merge.txt` +results in a conflict. + +------------------------ +Documentation/git-merge.txt conflict-marker-size=32 +------------------------ + + +Checking whitespace errors +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +`whitespace` +^^^^^^^^^^^^ + +The `core.whitespace` configuration variable allows you to define what +'diff' and 'apply' should consider whitespace errors for all paths in +the project (See 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 the `.gitattributes` +file at the toplevel (i.e. not in any subdirectory). The built-in +macro attribute "binary" is equivalent to: + +------------ +[attr]binary -diff -text +------------ + + EXAMPLE ------- @@ -421,6 +978,10 @@ frotz unspecified ---------------------------------------------------------------- +SEE ALSO +-------- +linkgit:git-check-attr[1]. + GIT --- -Part of the gitlink:git[7] suite +Part of the linkgit:git[1] suite |