1gitattributes(5) 2================ 3 4NAME 5---- 6gitattributes - defining attributes per path 7 8SYNOPSIS 9-------- 10$GIT_DIR/info/attributes, .gitattributes 11 12 13DESCRIPTION 14----------- 15 16A `gitattributes` file is a simple text file that gives 17`attributes` to pathnames. 18 19Each line in `gitattributes` file is of form: 20 21 pattern attr1 attr2 ... 22 23That is, a pattern followed by an attributes list, 24separated by whitespaces. When the pattern matches the 25path in question, the attributes listed on the line are given to 26the path. 27 28Each attribute can be in one of these states for a given path: 29 30Set:: 31 32 The path has the attribute with special value "true"; 33 this is specified by listing only the name of the 34 attribute in the attribute list. 35 36Unset:: 37 38 The path has the attribute with special value "false"; 39 this is specified by listing the name of the attribute 40 prefixed with a dash `-` in the attribute list. 41 42Set to a value:: 43 44 The path has the attribute with specified string value; 45 this is specified by listing the name of the attribute 46 followed by an equal sign `=` and its value in the 47 attribute list. 48 49Unspecified:: 50 51 No pattern matches the path, and nothing says if 52 the path has or does not have the attribute, the 53 attribute for the path is said to be Unspecified. 54 55When more than one pattern matches the path, a later line 56overrides an earlier line. This overriding is done per 57attribute. The rules how the pattern matches paths are the 58same as in `.gitignore` files; see linkgit:gitignore[5]. 59 60When deciding what attributes are assigned to a path, git 61consults `$GIT_DIR/info/attributes` file (which has the highest 62precedence), `.gitattributes` file in the same directory as the 63path in question, and its parent directories up to the toplevel of the 64work tree (the further the directory that contains `.gitattributes` 65is from the path in question, the lower its precedence). Finally 66global and system-wide files are considered (they have the lowest 67precedence). 68 69If you wish to affect only a single repository (i.e., to assign 70attributes to files that are particular to 71one user's workflow for that repository), then 72attributes should be placed in the `$GIT_DIR/info/attributes` file. 73Attributes which should be version-controlled and distributed to other 74repositories (i.e., attributes of interest to all users) should go into 75`.gitattributes` files. Attributes that should affect all repositories 76for a single user should be placed in a file specified by the 77`core.attributesfile` configuration option (see linkgit:git-config[1]). 78Attributes for all users on a system should be placed in the 79`$(prefix)/etc/gitattributes` file. 80 81Sometimes you would need to override an setting of an attribute 82for a path to `Unspecified` state. This can be done by listing 83the name of the attribute prefixed with an exclamation point `!`. 84 85 86EFFECTS 87------- 88 89Certain operations by git can be influenced by assigning 90particular attributes to a path. Currently, the following 91operations are attributes-aware. 92 93Checking-out and checking-in 94~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 95 96These attributes affect how the contents stored in the 97repository are copied to the working tree files when commands 98such as 'git checkout' and 'git merge' run. They also affect how 99git stores the contents you prepare in the working tree in the 100repository upon 'git add' and 'git commit'. 101 102`text` 103^^^^^^ 104 105This attribute enables and controls end-of-line normalization. When a 106text file is normalized, its line endings are converted to LF in the 107repository. To control what line ending style is used in the working 108directory, use the `eol` attribute for a single file and the 109`core.eol` configuration variable for all text files. 110 111Set:: 112 113 Setting the `text` attribute on a path enables end-of-line 114 normalization and marks the path as a text file. End-of-line 115 conversion takes place without guessing the content type. 116 117Unset:: 118 119 Unsetting the `text` attribute on a path tells git not to 120 attempt any end-of-line conversion upon checkin or checkout. 121 122Set to string value "auto":: 123 124 When `text` is set to "auto", the path is marked for automatic 125 end-of-line normalization. If git decides that the content is 126 text, its line endings are normalized to LF on checkin. 127 128Unspecified:: 129 130 If the `text` attribute is unspecified, git uses the 131 `core.autocrlf` configuration variable to determine if the 132 file should be converted. 133 134Any other value causes git to act as if `text` has been left 135unspecified. 136 137`eol` 138^^^^^ 139 140This attribute sets a specific line-ending style to be used in the 141working directory. It enables end-of-line normalization without any 142content checks, effectively setting the `text` attribute. 143 144Set to string value "crlf":: 145 146 This setting forces git to normalize line endings for this 147 file on checkin and convert them to CRLF when the file is 148 checked out. 149 150Set to string value "lf":: 151 152 This setting forces git to normalize line endings to LF on 153 checkin and prevents conversion to CRLF when the file is 154 checked out. 155 156Backwards compatibility with `crlf` attribute 157^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 158 159For backwards compatibility, the `crlf` attribute is interpreted as 160follows: 161 162------------------------ 163crlf text 164-crlf -text 165crlf=input eol=lf 166------------------------ 167 168End-of-line conversion 169^^^^^^^^^^^^^^^^^^^^^^ 170 171While git normally leaves file contents alone, it can be configured to 172normalize line endings to LF in the repository and, optionally, to 173convert them to CRLF when files are checked out. 174 175Here is an example that will make git normalize .txt, .vcproj and .sh 176files, ensure that .vcproj files have CRLF and .sh files have LF in 177the working directory, and prevent .jpg files from being normalized 178regardless of their content. 179 180------------------------ 181*.txt text 182*.vcproj eol=crlf 183*.sh eol=lf 184*.jpg -text 185------------------------ 186 187Other source code management systems normalize all text files in their 188repositories, and there are two ways to enable similar automatic 189normalization in git. 190 191If you simply want to have CRLF line endings in your working directory 192regardless of the repository you are working with, you can set the 193config variable "core.autocrlf" without changing any attributes. 194 195------------------------ 196[core] 197 autocrlf = true 198------------------------ 199 200This does not force normalization of all text files, but does ensure 201that text files that you introduce to the repository have their line 202endings normalized to LF when they are added, and that files that are 203already normalized in the repository stay normalized. 204 205If you want to interoperate with a source code management system that 206enforces end-of-line normalization, or you simply want all text files 207in your repository to be normalized, you should instead set the `text` 208attribute to "auto" for _all_ files. 209 210------------------------ 211* text=auto 212------------------------ 213 214This ensures that all files that git considers to be text will have 215normalized (LF) line endings in the repository. The `core.eol` 216configuration variable controls which line endings git will use for 217normalized files in your working directory; the default is to use the 218native line ending for your platform, or CRLF if `core.autocrlf` is 219set. 220 221NOTE: When `text=auto` normalization is enabled in an existing 222repository, any text files containing CRLFs should be normalized. If 223they are not they will be normalized the next time someone tries to 224change them, causing unfortunate misattribution. From a clean working 225directory: 226 227------------------------------------------------- 228$ echo "* text=auto" >>.gitattributes 229$ rm .git/index # Remove the index to force git to 230$ git reset # re-scan the working directory 231$ git status # Show files that will be normalized 232$ git add -u 233$ git add .gitattributes 234$ git commit -m "Introduce end-of-line normalization" 235------------------------------------------------- 236 237If any files that should not be normalized show up in 'git status', 238unset their `text` attribute before running 'git add -u'. 239 240------------------------ 241manual.pdf -text 242------------------------ 243 244Conversely, text files that git does not detect can have normalization 245enabled manually. 246 247------------------------ 248weirdchars.txt text 249------------------------ 250 251If `core.safecrlf` is set to "true" or "warn", git verifies if 252the conversion is reversible for the current setting of 253`core.autocrlf`. For "true", git rejects irreversible 254conversions; for "warn", git only prints a warning but accepts 255an irreversible conversion. The safety triggers to prevent such 256a conversion done to the files in the work tree, but there are a 257few exceptions. Even though... 258 259- 'git add' itself does not touch the files in the work tree, the 260 next checkout would, so the safety triggers; 261 262- 'git apply' to update a text file with a patch does touch the files 263 in the work tree, but the operation is about text files and CRLF 264 conversion is about fixing the line ending inconsistencies, so the 265 safety does not trigger; 266 267- 'git diff' itself does not touch the files in the work tree, it is 268 often run to inspect the changes you intend to next 'git add'. To 269 catch potential problems early, safety triggers. 270 271 272`ident` 273^^^^^^^ 274 275When the attribute `ident` is set for a path, git replaces 276`$Id$` in the blob object with `$Id:`, followed by the 27740-character hexadecimal blob object name, followed by a dollar 278sign `$` upon checkout. Any byte sequence that begins with 279`$Id:` and ends with `$` in the worktree file is replaced 280with `$Id$` upon check-in. 281 282 283`filter` 284^^^^^^^^ 285 286A `filter` attribute can be set to a string value that names a 287filter driver specified in the configuration. 288 289A filter driver consists of a `clean` command and a `smudge` 290command, either of which can be left unspecified. Upon 291checkout, when the `smudge` command is specified, the command is 292fed the blob object from its standard input, and its standard 293output is used to update the worktree file. Similarly, the 294`clean` command is used to convert the contents of worktree file 295upon checkin. 296 297A missing filter driver definition in the config is not an error 298but makes the filter a no-op passthru. 299 300The content filtering is done to massage the content into a 301shape that is more convenient for the platform, filesystem, and 302the user to use. The key phrase here is "more convenient" and not 303"turning something unusable into usable". In other words, the 304intent is that if someone unsets the filter driver definition, 305or does not have the appropriate filter program, the project 306should still be usable. 307 308For example, in .gitattributes, you would assign the `filter` 309attribute for paths. 310 311------------------------ 312*.c filter=indent 313------------------------ 314 315Then you would define a "filter.indent.clean" and "filter.indent.smudge" 316configuration in your .git/config to specify a pair of commands to 317modify the contents of C programs when the source files are checked 318in ("clean" is run) and checked out (no change is made because the 319command is "cat"). 320 321------------------------ 322[filter "indent"] 323 clean = indent 324 smudge = cat 325------------------------ 326 327For best results, `clean` should not alter its output further if it is 328run twice ("clean->clean" should be equivalent to "clean"), and 329multiple `smudge` commands should not alter `clean`'s output 330("smudge->smudge->clean" should be equivalent to "clean"). See the 331section on merging below. 332 333The "indent" filter is well-behaved in this regard: it will not modify 334input that is already correctly indented. In this case, the lack of a 335smudge filter means that the clean filter _must_ accept its own output 336without modifying it. 337 338Sequence "%f" on the filter command line is replaced with the name of 339the file the filter is working on. A filter might use this in keyword 340substitution. For example: 341 342------------------------ 343[filter "p4"] 344 clean = git-p4-filter --clean %f 345 smudge = git-p4-filter --smudge %f 346------------------------ 347 348 349Interaction between checkin/checkout attributes 350^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 351 352In the check-in codepath, the worktree file is first converted 353with `filter` driver (if specified and corresponding driver 354defined), then the result is processed with `ident` (if 355specified), and then finally with `text` (again, if specified 356and applicable). 357 358In the check-out codepath, the blob content is first converted 359with `text`, and then `ident` and fed to `filter`. 360 361 362Merging branches with differing checkin/checkout attributes 363^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 364 365If you have added attributes to a file that cause the canonical 366repository format for that file to change, such as adding a 367clean/smudge filter or text/eol/ident attributes, merging anything 368where the attribute is not in place would normally cause merge 369conflicts. 370 371To prevent these unnecessary merge conflicts, git can be told to run a 372virtual check-out and check-in of all three stages of a file when 373resolving a three-way merge by setting the `merge.renormalize` 374configuration variable. This prevents changes caused by check-in 375conversion from causing spurious merge conflicts when a converted file 376is merged with an unconverted file. 377 378As long as a "smudge->clean" results in the same output as a "clean" 379even on files that are already smudged, this strategy will 380automatically resolve all filter-related conflicts. Filters that do 381not act in this way may cause additional merge conflicts that must be 382resolved manually. 383 384 385Generating diff text 386~~~~~~~~~~~~~~~~~~~~ 387 388`diff` 389^^^^^^ 390 391The attribute `diff` affects how 'git' generates diffs for particular 392files. It can tell git whether to generate a textual patch for the path 393or to treat the path as a binary file. It can also affect what line is 394shown on the hunk header `@@ -k,l +n,m @@` line, tell git to use an 395external command to generate the diff, or ask git to convert binary 396files to a text format before generating the diff. 397 398Set:: 399 400 A path to which the `diff` attribute is set is treated 401 as text, even when they contain byte values that 402 normally never appear in text files, such as NUL. 403 404Unset:: 405 406 A path to which the `diff` attribute is unset will 407 generate `Binary files differ` (or a binary patch, if 408 binary patches are enabled). 409 410Unspecified:: 411 412 A path to which the `diff` attribute is unspecified 413 first gets its contents inspected, and if it looks like 414 text, it is treated as text. Otherwise it would 415 generate `Binary files differ`. 416 417String:: 418 419 Diff is shown using the specified diff driver. Each driver may 420 specify one or more options, as described in the following 421 section. The options for the diff driver "foo" are defined 422 by the configuration variables in the "diff.foo" section of the 423 git config file. 424 425 426Defining an external diff driver 427^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 428 429The definition of a diff driver is done in `gitconfig`, not 430`gitattributes` file, so strictly speaking this manual page is a 431wrong place to talk about it. However... 432 433To define an external diff driver `jcdiff`, add a section to your 434`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: 435 436---------------------------------------------------------------- 437[diff "jcdiff"] 438 command = j-c-diff 439---------------------------------------------------------------- 440 441When git needs to show you a diff for the path with `diff` 442attribute set to `jcdiff`, it calls the command you specified 443with the above configuration, i.e. `j-c-diff`, with 7 444parameters, just like `GIT_EXTERNAL_DIFF` program is called. 445See linkgit:git[1] for details. 446 447 448Defining a custom hunk-header 449^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 450 451Each group of changes (called a "hunk") in the textual diff output 452is prefixed with a line of the form: 453 454 @@ -k,l +n,m @@ TEXT 455 456This is called a 'hunk header'. The "TEXT" portion is by default a line 457that begins with an alphabet, an underscore or a dollar sign; this 458matches what GNU 'diff -p' output uses. This default selection however 459is not suited for some contents, and you can use a customized pattern 460to make a selection. 461 462First, in .gitattributes, you would assign the `diff` attribute 463for paths. 464 465------------------------ 466*.tex diff=tex 467------------------------ 468 469Then, you would define a "diff.tex.xfuncname" configuration to 470specify a regular expression that matches a line that you would 471want to appear as the hunk header "TEXT". Add a section to your 472`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: 473 474------------------------ 475[diff "tex"] 476 xfuncname = "^(\\\\(sub)*section\\{.*)$" 477------------------------ 478 479Note. A single level of backslashes are eaten by the 480configuration file parser, so you would need to double the 481backslashes; the pattern above picks a line that begins with a 482backslash, and zero or more occurrences of `sub` followed by 483`section` followed by open brace, to the end of line. 484 485There are a few built-in patterns to make this easier, and `tex` 486is one of them, so you do not have to write the above in your 487configuration file (you still need to enable this with the 488attribute mechanism, via `.gitattributes`). The following built in 489patterns are available: 490 491- `bibtex` suitable for files with BibTeX coded references. 492 493- `cpp` suitable for source code in the C and C++ languages. 494 495- `csharp` suitable for source code in the C# language. 496 497- `fortran` suitable for source code in the Fortran language. 498 499- `html` suitable for HTML/XHTML documents. 500 501- `java` suitable for source code in the Java language. 502 503- `matlab` suitable for source code in the MATLAB language. 504 505- `objc` suitable for source code in the Objective-C language. 506 507- `pascal` suitable for source code in the Pascal/Delphi language. 508 509- `perl` suitable for source code in the Perl language. 510 511- `php` suitable for source code in the PHP language. 512 513- `python` suitable for source code in the Python language. 514 515- `ruby` suitable for source code in the Ruby language. 516 517- `tex` suitable for source code for LaTeX documents. 518 519 520Customizing word diff 521^^^^^^^^^^^^^^^^^^^^^ 522 523You can customize the rules that `git diff --word-diff` uses to 524split words in a line, by specifying an appropriate regular expression 525in the "diff.*.wordRegex" configuration variable. For example, in TeX 526a backslash followed by a sequence of letters forms a command, but 527several such commands can be run together without intervening 528whitespace. To separate them, use a regular expression in your 529`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: 530 531------------------------ 532[diff "tex"] 533 wordRegex = "\\\\[a-zA-Z]+|[{}]|\\\\.|[^\\{}[:space:]]+" 534------------------------ 535 536A built-in pattern is provided for all languages listed in the 537previous section. 538 539 540Performing text diffs of binary files 541^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 542 543Sometimes it is desirable to see the diff of a text-converted 544version of some binary files. For example, a word processor 545document can be converted to an ASCII text representation, and 546the diff of the text shown. Even though this conversion loses 547some information, the resulting diff is useful for human 548viewing (but cannot be applied directly). 549 550The `textconv` config option is used to define a program for 551performing such a conversion. The program should take a single 552argument, the name of a file to convert, and produce the 553resulting text on stdout. 554 555For example, to show the diff of the exif information of a 556file instead of the binary information (assuming you have the 557exif tool installed), add the following section to your 558`$GIT_DIR/config` file (or `$HOME/.gitconfig` file): 559 560------------------------ 561[diff "jpg"] 562 textconv = exif 563------------------------ 564 565NOTE: The text conversion is generally a one-way conversion; 566in this example, we lose the actual image contents and focus 567just on the text data. This means that diffs generated by 568textconv are _not_ suitable for applying. For this reason, 569only `git diff` and the `git log` family of commands (i.e., 570log, whatchanged, show) will perform text conversion. `git 571format-patch` will never generate this output. If you want to 572send somebody a text-converted diff of a binary file (e.g., 573because it quickly conveys the changes you have made), you 574should generate it separately and send it as a comment _in 575addition to_ the usual binary diff that you might send. 576 577Because text conversion can be slow, especially when doing a 578large number of them with `git log -p`, git provides a mechanism 579to cache the output and use it in future diffs. To enable 580caching, set the "cachetextconv" variable in your diff driver's 581config. For example: 582 583------------------------ 584[diff "jpg"] 585 textconv = exif 586 cachetextconv = true 587------------------------ 588 589This will cache the result of running "exif" on each blob 590indefinitely. If you change the textconv config variable for a 591diff driver, git will automatically invalidate the cache entries 592and re-run the textconv filter. If you want to invalidate the 593cache manually (e.g., because your version of "exif" was updated 594and now produces better output), you can remove the cache 595manually with `git update-ref -d refs/notes/textconv/jpg` (where 596"jpg" is the name of the diff driver, as in the example above). 597 598Choosing textconv versus external diff 599^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 600 601If you want to show differences between binary or specially-formatted 602blobs in your repository, you can choose to use either an external diff 603command, or to use textconv to convert them to a diff-able text format. 604Which method you choose depends on your exact situation. 605 606The advantage of using an external diff command is flexibility. You are 607not bound to find line-oriented changes, nor is it necessary for the 608output to resemble unified diff. You are free to locate and report 609changes in the most appropriate way for your data format. 610 611A textconv, by comparison, is much more limiting. You provide a 612transformation of the data into a line-oriented text format, and git 613uses its regular diff tools to generate the output. There are several 614advantages to choosing this method: 615 6161. Ease of use. It is often much simpler to write a binary to text 617 transformation than it is to perform your own diff. In many cases, 618 existing programs can be used as textconv filters (e.g., exif, 619 odt2txt). 620 6212. Git diff features. By performing only the transformation step 622 yourself, you can still utilize many of git's diff features, 623 including colorization, word-diff, and combined diffs for merges. 624 6253. Caching. Textconv caching can speed up repeated diffs, such as those 626 you might trigger by running `git log -p`. 627 628 629Marking files as binary 630^^^^^^^^^^^^^^^^^^^^^^^ 631 632Git usually guesses correctly whether a blob contains text or binary 633data by examining the beginning of the contents. However, sometimes you 634may want to override its decision, either because a blob contains binary 635data later in the file, or because the content, while technically 636composed of text characters, is opaque to a human reader. For example, 637many postscript files contain only ascii characters, but produce noisy 638and meaningless diffs. 639 640The simplest way to mark a file as binary is to unset the diff 641attribute in the `.gitattributes` file: 642 643------------------------ 644*.ps -diff 645------------------------ 646 647This will cause git to generate `Binary files differ` (or a binary 648patch, if binary patches are enabled) instead of a regular diff. 649 650However, one may also want to specify other diff driver attributes. For 651example, you might want to use `textconv` to convert postscript files to 652an ascii representation for human viewing, but otherwise treat them as 653binary files. You cannot specify both `-diff` and `diff=ps` attributes. 654The solution is to use the `diff.*.binary` config option: 655 656------------------------ 657[diff "ps"] 658 textconv = ps2ascii 659 binary = true 660------------------------ 661 662Performing a three-way merge 663~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 664 665`merge` 666^^^^^^^ 667 668The attribute `merge` affects how three versions of a file are 669merged when a file-level merge is necessary during `git merge`, 670and other commands such as `git revert` and `git cherry-pick`. 671 672Set:: 673 674 Built-in 3-way merge driver is used to merge the 675 contents in a way similar to 'merge' command of `RCS` 676 suite. This is suitable for ordinary text files. 677 678Unset:: 679 680 Take the version from the current branch as the 681 tentative merge result, and declare that the merge has 682 conflicts. This is suitable for binary files that do 683 not have a well-defined merge semantics. 684 685Unspecified:: 686 687 By default, this uses the same built-in 3-way merge 688 driver as is the case when the `merge` attribute is set. 689 However, the `merge.default` configuration variable can name 690 different merge driver to be used with paths for which the 691 `merge` attribute is unspecified. 692 693String:: 694 695 3-way merge is performed using the specified custom 696 merge driver. The built-in 3-way merge driver can be 697 explicitly specified by asking for "text" driver; the 698 built-in "take the current branch" driver can be 699 requested with "binary". 700 701 702Built-in merge drivers 703^^^^^^^^^^^^^^^^^^^^^^ 704 705There are a few built-in low-level merge drivers defined that 706can be asked for via the `merge` attribute. 707 708text:: 709 710 Usual 3-way file level merge for text files. Conflicted 711 regions are marked with conflict markers `<<<<<<<`, 712 `=======` and `>>>>>>>`. The version from your branch 713 appears before the `=======` marker, and the version 714 from the merged branch appears after the `=======` 715 marker. 716 717binary:: 718 719 Keep the version from your branch in the work tree, but 720 leave the path in the conflicted state for the user to 721 sort out. 722 723union:: 724 725 Run 3-way file level merge for text files, but take 726 lines from both versions, instead of leaving conflict 727 markers. This tends to leave the added lines in the 728 resulting file in random order and the user should 729 verify the result. Do not use this if you do not 730 understand the implications. 731 732 733Defining a custom merge driver 734^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 735 736The definition of a merge driver is done in the `.git/config` 737file, not in the `gitattributes` file, so strictly speaking this 738manual page is a wrong place to talk about it. However... 739 740To define a custom merge driver `filfre`, add a section to your 741`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this: 742 743---------------------------------------------------------------- 744[merge "filfre"] 745 name = feel-free merge driver 746 driver = filfre %O %A %B 747 recursive = binary 748---------------------------------------------------------------- 749 750The `merge.*.name` variable gives the driver a human-readable 751name. 752 753The `merge.*.driver` variable's value is used to construct a 754command to run to merge ancestor's version (`%O`), current 755version (`%A`) and the other branches' version (`%B`). These 756three tokens are replaced with the names of temporary files that 757hold the contents of these versions when the command line is 758built. Additionally, %L will be replaced with the conflict marker 759size (see below). 760 761The merge driver is expected to leave the result of the merge in 762the file named with `%A` by overwriting it, and exit with zero 763status if it managed to merge them cleanly, or non-zero if there 764were conflicts. 765 766The `merge.*.recursive` variable specifies what other merge 767driver to use when the merge driver is called for an internal 768merge between common ancestors, when there are more than one. 769When left unspecified, the driver itself is used for both 770internal merge and the final merge. 771 772 773`conflict-marker-size` 774^^^^^^^^^^^^^^^^^^^^^^ 775 776This attribute controls the length of conflict markers left in 777the work tree file during a conflicted merge. Only setting to 778the value to a positive integer has any meaningful effect. 779 780For example, this line in `.gitattributes` can be used to tell the merge 781machinery to leave much longer (instead of the usual 7-character-long) 782conflict markers when merging the file `Documentation/git-merge.txt` 783results in a conflict. 784 785------------------------ 786Documentation/git-merge.txt conflict-marker-size=32 787------------------------ 788 789 790Checking whitespace errors 791~~~~~~~~~~~~~~~~~~~~~~~~~~ 792 793`whitespace` 794^^^^^^^^^^^^ 795 796The `core.whitespace` configuration variable allows you to define what 797'diff' and 'apply' should consider whitespace errors for all paths in 798the project (See linkgit:git-config[1]). This attribute gives you finer 799control per path. 800 801Set:: 802 803 Notice all types of potential whitespace errors known to git. 804 The tab width is taken from the value of the `core.whitespace` 805 configuration variable. 806 807Unset:: 808 809 Do not notice anything as error. 810 811Unspecified:: 812 813 Use the value of the `core.whitespace` configuration variable to 814 decide what to notice as error. 815 816String:: 817 818 Specify a comma separate list of common whitespace problems to 819 notice in the same format as the `core.whitespace` configuration 820 variable. 821 822 823Creating an archive 824~~~~~~~~~~~~~~~~~~~ 825 826`export-ignore` 827^^^^^^^^^^^^^^^ 828 829Files and directories with the attribute `export-ignore` won't be added to 830archive files. 831 832`export-subst` 833^^^^^^^^^^^^^^ 834 835If the attribute `export-subst` is set for a file then git will expand 836several placeholders when adding this file to an archive. The 837expansion depends on the availability of a commit ID, i.e., if 838linkgit:git-archive[1] has been given a tree instead of a commit or a 839tag then no replacement will be done. The placeholders are the same 840as those for the option `--pretty=format:` of linkgit:git-log[1], 841except that they need to be wrapped like this: `$Format:PLACEHOLDERS$` 842in the file. E.g. the string `$Format:%H$` will be replaced by the 843commit hash. 844 845 846Packing objects 847~~~~~~~~~~~~~~~ 848 849`delta` 850^^^^^^^ 851 852Delta compression will not be attempted for blobs for paths with the 853attribute `delta` set to false. 854 855 856Viewing files in GUI tools 857~~~~~~~~~~~~~~~~~~~~~~~~~~ 858 859`encoding` 860^^^^^^^^^^ 861 862The value of this attribute specifies the character encoding that should 863be used by GUI tools (e.g. linkgit:gitk[1] and linkgit:git-gui[1]) to 864display the contents of the relevant file. Note that due to performance 865considerations linkgit:gitk[1] does not use this attribute unless you 866manually enable per-file encodings in its options. 867 868If this attribute is not set or has an invalid value, the value of the 869`gui.encoding` configuration variable is used instead 870(See linkgit:git-config[1]). 871 872 873USING MACRO ATTRIBUTES 874---------------------- 875 876You do not want any end-of-line conversions applied to, nor textual diffs 877produced for, any binary file you track. You would need to specify e.g. 878 879------------ 880*.jpg -text -diff 881------------ 882 883but that may become cumbersome, when you have many attributes. Using 884macro attributes, you can define an attribute that, when set, also 885sets or unsets a number of other attributes at the same time. The 886system knows a built-in macro attribute, `binary`: 887 888------------ 889*.jpg binary 890------------ 891 892Setting the "binary" attribute also unsets the "text" and "diff" 893attributes as above. Note that macro attributes can only be "Set", 894though setting one might have the effect of setting or unsetting other 895attributes or even returning other attributes to the "Unspecified" 896state. 897 898 899DEFINING MACRO ATTRIBUTES 900------------------------- 901 902Custom macro attributes can be defined only in the `.gitattributes` 903file at the toplevel (i.e. not in any subdirectory). The built-in 904macro attribute "binary" is equivalent to: 905 906------------ 907[attr]binary -diff -text 908------------ 909 910 911EXAMPLE 912------- 913 914If you have these three `gitattributes` file: 915 916---------------------------------------------------------------- 917(in $GIT_DIR/info/attributes) 918 919a* foo !bar -baz 920 921(in .gitattributes) 922abc foo bar baz 923 924(in t/.gitattributes) 925ab* merge=filfre 926abc -foo -bar 927*.c frotz 928---------------------------------------------------------------- 929 930the attributes given to path `t/abc` are computed as follows: 931 9321. By examining `t/.gitattributes` (which is in the same 933 directory as the path in question), git finds that the first 934 line matches. `merge` attribute is set. It also finds that 935 the second line matches, and attributes `foo` and `bar` 936 are unset. 937 9382. Then it examines `.gitattributes` (which is in the parent 939 directory), and finds that the first line matches, but 940 `t/.gitattributes` file already decided how `merge`, `foo` 941 and `bar` attributes should be given to this path, so it 942 leaves `foo` and `bar` unset. Attribute `baz` is set. 943 9443. Finally it examines `$GIT_DIR/info/attributes`. This file 945 is used to override the in-tree settings. The first line is 946 a match, and `foo` is set, `bar` is reverted to unspecified 947 state, and `baz` is unset. 948 949As the result, the attributes assignment to `t/abc` becomes: 950 951---------------------------------------------------------------- 952foo set to true 953bar unspecified 954baz set to false 955merge set to string value "filfre" 956frotz unspecified 957---------------------------------------------------------------- 958 959 960SEE ALSO 961-------- 962linkgit:git-check-attr[1]. 963 964GIT 965--- 966Part of the linkgit:git[1] suite