Documentation / diff-options.txton commit diff: disable compaction heuristic for now (5580b27)
   1// Please don't remove this comment as asciidoc behaves badly when
   2// the first non-empty line is ifdef/ifndef. The symptom is that
   3// without this comment the <git-diff-core> attribute conditionally
   4// defined below ends up being defined unconditionally.
   5// Last checked with asciidoc 7.0.2.
   6
   7ifndef::git-format-patch[]
   8ifndef::git-diff[]
   9ifndef::git-log[]
  10:git-diff-core: 1
  11endif::git-log[]
  12endif::git-diff[]
  13endif::git-format-patch[]
  14
  15ifdef::git-format-patch[]
  16-p::
  17--no-stat::
  18        Generate plain patches without any diffstats.
  19endif::git-format-patch[]
  20
  21ifndef::git-format-patch[]
  22-p::
  23-u::
  24--patch::
  25        Generate patch (see section on generating patches).
  26ifdef::git-diff[]
  27        This is the default.
  28endif::git-diff[]
  29endif::git-format-patch[]
  30
  31-s::
  32--no-patch::
  33        Suppress diff output. Useful for commands like `git show` that
  34        show the patch by default, or to cancel the effect of `--patch`.
  35
  36-U<n>::
  37--unified=<n>::
  38        Generate diffs with <n> lines of context instead of
  39        the usual three.
  40ifndef::git-format-patch[]
  41        Implies `-p`.
  42endif::git-format-patch[]
  43
  44ifndef::git-format-patch[]
  45--raw::
  46ifndef::git-log[]
  47        Generate the diff in raw format.
  48ifdef::git-diff-core[]
  49        This is the default.
  50endif::git-diff-core[]
  51endif::git-log[]
  52ifdef::git-log[]
  53        For each commit, show a summary of changes using the raw diff
  54        format. See the "RAW OUTPUT FORMAT" section of
  55        linkgit:git-diff[1]. This is different from showing the log
  56        itself in raw format, which you can achieve with
  57        `--format=raw`.
  58endif::git-log[]
  59endif::git-format-patch[]
  60
  61ifndef::git-format-patch[]
  62--patch-with-raw::
  63        Synonym for `-p --raw`.
  64endif::git-format-patch[]
  65
  66--compaction-heuristic::
  67--no-compaction-heuristic::
  68        These are to help debugging and tuning an experimental
  69        heuristic (which is off by default) that shifts the hunk
  70        boundary in an attempt to make the resulting patch easier
  71        to read.
  72
  73--minimal::
  74        Spend extra time to make sure the smallest possible
  75        diff is produced.
  76
  77--patience::
  78        Generate a diff using the "patience diff" algorithm.
  79
  80--histogram::
  81        Generate a diff using the "histogram diff" algorithm.
  82
  83--diff-algorithm={patience|minimal|histogram|myers}::
  84        Choose a diff algorithm. The variants are as follows:
  85+
  86--
  87`default`, `myers`;;
  88        The basic greedy diff algorithm. Currently, this is the default.
  89`minimal`;;
  90        Spend extra time to make sure the smallest possible diff is
  91        produced.
  92`patience`;;
  93        Use "patience diff" algorithm when generating patches.
  94`histogram`;;
  95        This algorithm extends the patience algorithm to "support
  96        low-occurrence common elements".
  97--
  98+
  99For instance, if you configured diff.algorithm variable to a
 100non-default value and want to use the default one, then you
 101have to use `--diff-algorithm=default` option.
 102
 103--stat[=<width>[,<name-width>[,<count>]]]::
 104        Generate a diffstat. By default, as much space as necessary
 105        will be used for the filename part, and the rest for the graph
 106        part. Maximum width defaults to terminal width, or 80 columns
 107        if not connected to a terminal, and can be overridden by
 108        `<width>`. The width of the filename part can be limited by
 109        giving another width `<name-width>` after a comma. The width
 110        of the graph part can be limited by using
 111        `--stat-graph-width=<width>` (affects all commands generating
 112        a stat graph) or by setting `diff.statGraphWidth=<width>`
 113        (does not affect `git format-patch`).
 114        By giving a third parameter `<count>`, you can limit the
 115        output to the first `<count>` lines, followed by `...` if
 116        there are more.
 117+
 118These parameters can also be set individually with `--stat-width=<width>`,
 119`--stat-name-width=<name-width>` and `--stat-count=<count>`.
 120
 121--numstat::
 122        Similar to `--stat`, but shows number of added and
 123        deleted lines in decimal notation and pathname without
 124        abbreviation, to make it more machine friendly.  For
 125        binary files, outputs two `-` instead of saying
 126        `0 0`.
 127
 128--shortstat::
 129        Output only the last line of the `--stat` format containing total
 130        number of modified files, as well as number of added and deleted
 131        lines.
 132
 133--dirstat[=<param1,param2,...>]::
 134        Output the distribution of relative amount of changes for each
 135        sub-directory. The behavior of `--dirstat` can be customized by
 136        passing it a comma separated list of parameters.
 137        The defaults are controlled by the `diff.dirstat` configuration
 138        variable (see linkgit:git-config[1]).
 139        The following parameters are available:
 140+
 141--
 142`changes`;;
 143        Compute the dirstat numbers by counting the lines that have been
 144        removed from the source, or added to the destination. This ignores
 145        the amount of pure code movements within a file.  In other words,
 146        rearranging lines in a file is not counted as much as other changes.
 147        This is the default behavior when no parameter is given.
 148`lines`;;
 149        Compute the dirstat numbers by doing the regular line-based diff
 150        analysis, and summing the removed/added line counts. (For binary
 151        files, count 64-byte chunks instead, since binary files have no
 152        natural concept of lines). This is a more expensive `--dirstat`
 153        behavior than the `changes` behavior, but it does count rearranged
 154        lines within a file as much as other changes. The resulting output
 155        is consistent with what you get from the other `--*stat` options.
 156`files`;;
 157        Compute the dirstat numbers by counting the number of files changed.
 158        Each changed file counts equally in the dirstat analysis. This is
 159        the computationally cheapest `--dirstat` behavior, since it does
 160        not have to look at the file contents at all.
 161`cumulative`;;
 162        Count changes in a child directory for the parent directory as well.
 163        Note that when using `cumulative`, the sum of the percentages
 164        reported may exceed 100%. The default (non-cumulative) behavior can
 165        be specified with the `noncumulative` parameter.
 166<limit>;;
 167        An integer parameter specifies a cut-off percent (3% by default).
 168        Directories contributing less than this percentage of the changes
 169        are not shown in the output.
 170--
 171+
 172Example: The following will count changed files, while ignoring
 173directories with less than 10% of the total amount of changed files,
 174and accumulating child directory counts in the parent directories:
 175`--dirstat=files,10,cumulative`.
 176
 177--summary::
 178        Output a condensed summary of extended header information
 179        such as creations, renames and mode changes.
 180
 181ifndef::git-format-patch[]
 182--patch-with-stat::
 183        Synonym for `-p --stat`.
 184endif::git-format-patch[]
 185
 186ifndef::git-format-patch[]
 187
 188-z::
 189ifdef::git-log[]
 190        Separate the commits with NULs instead of with new newlines.
 191+
 192Also, when `--raw` or `--numstat` has been given, do not munge
 193pathnames and use NULs as output field terminators.
 194endif::git-log[]
 195ifndef::git-log[]
 196        When `--raw`, `--numstat`, `--name-only` or `--name-status` has been
 197        given, do not munge pathnames and use NULs as output field terminators.
 198endif::git-log[]
 199+
 200Without this option, each pathname output will have TAB, LF, double quotes,
 201and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
 202respectively, and the pathname will be enclosed in double quotes if
 203any of those replacements occurred.
 204
 205--name-only::
 206        Show only names of changed files.
 207
 208--name-status::
 209        Show only names and status of changed files. See the description
 210        of the `--diff-filter` option on what the status letters mean.
 211
 212--submodule[=<format>]::
 213        Specify how differences in submodules are shown.  When `--submodule`
 214        or `--submodule=log` is given, the 'log' format is used.  This format lists
 215        the commits in the range like linkgit:git-submodule[1] `summary` does.
 216        Omitting the `--submodule` option or specifying `--submodule=short`,
 217        uses the 'short' format. This format just shows the names of the commits
 218        at the beginning and end of the range.  Can be tweaked via the
 219        `diff.submodule` configuration variable.
 220
 221--color[=<when>]::
 222        Show colored diff.
 223        `--color` (i.e. without '=<when>') is the same as `--color=always`.
 224        '<when>' can be one of `always`, `never`, or `auto`.
 225ifdef::git-diff[]
 226        It can be changed by the `color.ui` and `color.diff`
 227        configuration settings.
 228endif::git-diff[]
 229
 230--no-color::
 231        Turn off colored diff.
 232ifdef::git-diff[]
 233        This can be used to override configuration settings.
 234endif::git-diff[]
 235        It is the same as `--color=never`.
 236
 237--word-diff[=<mode>]::
 238        Show a word diff, using the <mode> to delimit changed words.
 239        By default, words are delimited by whitespace; see
 240        `--word-diff-regex` below.  The <mode> defaults to 'plain', and
 241        must be one of:
 242+
 243--
 244color::
 245        Highlight changed words using only colors.  Implies `--color`.
 246plain::
 247        Show words as `[-removed-]` and `{+added+}`.  Makes no
 248        attempts to escape the delimiters if they appear in the input,
 249        so the output may be ambiguous.
 250porcelain::
 251        Use a special line-based format intended for script
 252        consumption.  Added/removed/unchanged runs are printed in the
 253        usual unified diff format, starting with a `+`/`-`/` `
 254        character at the beginning of the line and extending to the
 255        end of the line.  Newlines in the input are represented by a
 256        tilde `~` on a line of its own.
 257none::
 258        Disable word diff again.
 259--
 260+
 261Note that despite the name of the first mode, color is used to
 262highlight the changed parts in all modes if enabled.
 263
 264--word-diff-regex=<regex>::
 265        Use <regex> to decide what a word is, instead of considering
 266        runs of non-whitespace to be a word.  Also implies
 267        `--word-diff` unless it was already enabled.
 268+
 269Every non-overlapping match of the
 270<regex> is considered a word.  Anything between these matches is
 271considered whitespace and ignored(!) for the purposes of finding
 272differences.  You may want to append `|[^[:space:]]` to your regular
 273expression to make sure that it matches all non-whitespace characters.
 274A match that contains a newline is silently truncated(!) at the
 275newline.
 276+
 277The regex can also be set via a diff driver or configuration option, see
 278linkgit:gitattributes[1] or linkgit:git-config[1].  Giving it explicitly
 279overrides any diff driver or configuration setting.  Diff drivers
 280override configuration settings.
 281
 282--color-words[=<regex>]::
 283        Equivalent to `--word-diff=color` plus (if a regex was
 284        specified) `--word-diff-regex=<regex>`.
 285endif::git-format-patch[]
 286
 287--no-renames::
 288        Turn off rename detection, even when the configuration
 289        file gives the default to do so.
 290
 291ifndef::git-format-patch[]
 292--check::
 293        Warn if changes introduce whitespace errors.  What are
 294        considered whitespace errors is controlled by `core.whitespace`
 295        configuration.  By default, trailing whitespaces (including
 296        lines that solely consist of whitespaces) and a space character
 297        that is immediately followed by a tab character inside the
 298        initial indent of the line are considered whitespace errors.
 299        Exits with non-zero status if problems are found. Not compatible
 300        with --exit-code.
 301endif::git-format-patch[]
 302
 303--full-index::
 304        Instead of the first handful of characters, show the full
 305        pre- and post-image blob object names on the "index"
 306        line when generating patch format output.
 307
 308--binary::
 309        In addition to `--full-index`, output a binary diff that
 310        can be applied with `git-apply`.
 311
 312--abbrev[=<n>]::
 313        Instead of showing the full 40-byte hexadecimal object
 314        name in diff-raw format output and diff-tree header
 315        lines, show only a partial prefix.  This is
 316        independent of the `--full-index` option above, which controls
 317        the diff-patch output format.  Non default number of
 318        digits can be specified with `--abbrev=<n>`.
 319
 320-B[<n>][/<m>]::
 321--break-rewrites[=[<n>][/<m>]]::
 322        Break complete rewrite changes into pairs of delete and
 323        create. This serves two purposes:
 324+
 325It affects the way a change that amounts to a total rewrite of a file
 326not as a series of deletion and insertion mixed together with a very
 327few lines that happen to match textually as the context, but as a
 328single deletion of everything old followed by a single insertion of
 329everything new, and the number `m` controls this aspect of the -B
 330option (defaults to 60%). `-B/70%` specifies that less than 30% of the
 331original should remain in the result for Git to consider it a total
 332rewrite (i.e. otherwise the resulting patch will be a series of
 333deletion and insertion mixed together with context lines).
 334+
 335When used with -M, a totally-rewritten file is also considered as the
 336source of a rename (usually -M only considers a file that disappeared
 337as the source of a rename), and the number `n` controls this aspect of
 338the -B option (defaults to 50%). `-B20%` specifies that a change with
 339addition and deletion compared to 20% or more of the file's size are
 340eligible for being picked up as a possible source of a rename to
 341another file.
 342
 343-M[<n>]::
 344--find-renames[=<n>]::
 345ifndef::git-log[]
 346        Detect renames.
 347endif::git-log[]
 348ifdef::git-log[]
 349        If generating diffs, detect and report renames for each commit.
 350        For following files across renames while traversing history, see
 351        `--follow`.
 352endif::git-log[]
 353        If `n` is specified, it is a threshold on the similarity
 354        index (i.e. amount of addition/deletions compared to the
 355        file's size). For example, `-M90%` means Git should consider a
 356        delete/add pair to be a rename if more than 90% of the file
 357        hasn't changed.  Without a `%` sign, the number is to be read as
 358        a fraction, with a decimal point before it.  I.e., `-M5` becomes
 359        0.5, and is thus the same as `-M50%`.  Similarly, `-M05` is
 360        the same as `-M5%`.  To limit detection to exact renames, use
 361        `-M100%`.  The default similarity index is 50%.
 362
 363-C[<n>]::
 364--find-copies[=<n>]::
 365        Detect copies as well as renames.  See also `--find-copies-harder`.
 366        If `n` is specified, it has the same meaning as for `-M<n>`.
 367
 368--find-copies-harder::
 369        For performance reasons, by default, `-C` option finds copies only
 370        if the original file of the copy was modified in the same
 371        changeset.  This flag makes the command
 372        inspect unmodified files as candidates for the source of
 373        copy.  This is a very expensive operation for large
 374        projects, so use it with caution.  Giving more than one
 375        `-C` option has the same effect.
 376
 377-D::
 378--irreversible-delete::
 379        Omit the preimage for deletes, i.e. print only the header but not
 380        the diff between the preimage and `/dev/null`. The resulting patch
 381        is not meant to be applied with `patch` or `git apply`; this is
 382        solely for people who want to just concentrate on reviewing the
 383        text after the change. In addition, the output obviously lack
 384        enough information to apply such a patch in reverse, even manually,
 385        hence the name of the option.
 386+
 387When used together with `-B`, omit also the preimage in the deletion part
 388of a delete/create pair.
 389
 390-l<num>::
 391        The `-M` and `-C` options require O(n^2) processing time where n
 392        is the number of potential rename/copy targets.  This
 393        option prevents rename/copy detection from running if
 394        the number of rename/copy targets exceeds the specified
 395        number.
 396
 397ifndef::git-format-patch[]
 398--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]::
 399        Select only files that are Added (`A`), Copied (`C`),
 400        Deleted (`D`), Modified (`M`), Renamed (`R`), have their
 401        type (i.e. regular file, symlink, submodule, ...) changed (`T`),
 402        are Unmerged (`U`), are
 403        Unknown (`X`), or have had their pairing Broken (`B`).
 404        Any combination of the filter characters (including none) can be used.
 405        When `*` (All-or-none) is added to the combination, all
 406        paths are selected if there is any file that matches
 407        other criteria in the comparison; if there is no file
 408        that matches other criteria, nothing is selected.
 409
 410-S<string>::
 411        Look for differences that change the number of occurrences of
 412        the specified string (i.e. addition/deletion) in a file.
 413        Intended for the scripter's use.
 414+
 415It is useful when you're looking for an exact block of code (like a
 416struct), and want to know the history of that block since it first
 417came into being: use the feature iteratively to feed the interesting
 418block in the preimage back into `-S`, and keep going until you get the
 419very first version of the block.
 420
 421-G<regex>::
 422        Look for differences whose patch text contains added/removed
 423        lines that match <regex>.
 424+
 425To illustrate the difference between `-S<regex> --pickaxe-regex` and
 426`-G<regex>`, consider a commit with the following diff in the same
 427file:
 428+
 429----
 430+    return !regexec(regexp, two->ptr, 1, &regmatch, 0);
 431...
 432-    hit = !regexec(regexp, mf2.ptr, 1, &regmatch, 0);
 433----
 434+
 435While `git log -G"regexec\(regexp"` will show this commit, `git log
 436-S"regexec\(regexp" --pickaxe-regex` will not (because the number of
 437occurrences of that string did not change).
 438+
 439See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more
 440information.
 441
 442--pickaxe-all::
 443        When `-S` or `-G` finds a change, show all the changes in that
 444        changeset, not just the files that contain the change
 445        in <string>.
 446
 447--pickaxe-regex::
 448        Treat the <string> given to `-S` as an extended POSIX regular
 449        expression to match.
 450endif::git-format-patch[]
 451
 452-O<orderfile>::
 453        Output the patch in the order specified in the
 454        <orderfile>, which has one shell glob pattern per line.
 455        This overrides the `diff.orderFile` configuration variable
 456        (see linkgit:git-config[1]).  To cancel `diff.orderFile`,
 457        use `-O/dev/null`.
 458
 459ifndef::git-format-patch[]
 460-R::
 461        Swap two inputs; that is, show differences from index or
 462        on-disk file to tree contents.
 463
 464--relative[=<path>]::
 465        When run from a subdirectory of the project, it can be
 466        told to exclude changes outside the directory and show
 467        pathnames relative to it with this option.  When you are
 468        not in a subdirectory (e.g. in a bare repository), you
 469        can name which subdirectory to make the output relative
 470        to by giving a <path> as an argument.
 471endif::git-format-patch[]
 472
 473-a::
 474--text::
 475        Treat all files as text.
 476
 477--ignore-space-at-eol::
 478        Ignore changes in whitespace at EOL.
 479
 480-b::
 481--ignore-space-change::
 482        Ignore changes in amount of whitespace.  This ignores whitespace
 483        at line end, and considers all other sequences of one or
 484        more whitespace characters to be equivalent.
 485
 486-w::
 487--ignore-all-space::
 488        Ignore whitespace when comparing lines.  This ignores
 489        differences even if one line has whitespace where the other
 490        line has none.
 491
 492--ignore-blank-lines::
 493        Ignore changes whose lines are all blank.
 494
 495--inter-hunk-context=<lines>::
 496        Show the context between diff hunks, up to the specified number
 497        of lines, thereby fusing hunks that are close to each other.
 498
 499-W::
 500--function-context::
 501        Show whole surrounding functions of changes.
 502
 503ifndef::git-format-patch[]
 504ifndef::git-log[]
 505--exit-code::
 506        Make the program exit with codes similar to diff(1).
 507        That is, it exits with 1 if there were differences and
 508        0 means no differences.
 509
 510--quiet::
 511        Disable all output of the program. Implies `--exit-code`.
 512endif::git-log[]
 513endif::git-format-patch[]
 514
 515--ext-diff::
 516        Allow an external diff helper to be executed. If you set an
 517        external diff driver with linkgit:gitattributes[5], you need
 518        to use this option with linkgit:git-log[1] and friends.
 519
 520--no-ext-diff::
 521        Disallow external diff drivers.
 522
 523--textconv::
 524--no-textconv::
 525        Allow (or disallow) external text conversion filters to be run
 526        when comparing binary files. See linkgit:gitattributes[5] for
 527        details. Because textconv filters are typically a one-way
 528        conversion, the resulting diff is suitable for human
 529        consumption, but cannot be applied. For this reason, textconv
 530        filters are enabled by default only for linkgit:git-diff[1] and
 531        linkgit:git-log[1], but not for linkgit:git-format-patch[1] or
 532        diff plumbing commands.
 533
 534--ignore-submodules[=<when>]::
 535        Ignore changes to submodules in the diff generation. <when> can be
 536        either "none", "untracked", "dirty" or "all", which is the default.
 537        Using "none" will consider the submodule modified when it either contains
 538        untracked or modified files or its HEAD differs from the commit recorded
 539        in the superproject and can be used to override any settings of the
 540        'ignore' option in linkgit:git-config[1] or linkgit:gitmodules[5]. When
 541        "untracked" is used submodules are not considered dirty when they only
 542        contain untracked content (but they are still scanned for modified
 543        content). Using "dirty" ignores all changes to the work tree of submodules,
 544        only changes to the commits stored in the superproject are shown (this was
 545        the behavior until 1.7.0). Using "all" hides all changes to submodules.
 546
 547--src-prefix=<prefix>::
 548        Show the given source prefix instead of "a/".
 549
 550--dst-prefix=<prefix>::
 551        Show the given destination prefix instead of "b/".
 552
 553--no-prefix::
 554        Do not show any source or destination prefix.
 555
 556For more detailed explanation on these common options, see also
 557linkgit:gitdiffcore[7].