Documentation / diff-options.txton commit for_each_string_list_item: avoid undefined behavior for empty list (ac7da78)
   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[]
  29
  30-s::
  31--no-patch::
  32        Suppress diff output. Useful for commands like `git show` that
  33        show the patch by default, or to cancel the effect of `--patch`.
  34endif::git-format-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
  66include::diff-heuristic-options.txt[]
  67
  68--minimal::
  69        Spend extra time to make sure the smallest possible
  70        diff is produced.
  71
  72--patience::
  73        Generate a diff using the "patience diff" algorithm.
  74
  75--histogram::
  76        Generate a diff using the "histogram diff" algorithm.
  77
  78--diff-algorithm={patience|minimal|histogram|myers}::
  79        Choose a diff algorithm. The variants are as follows:
  80+
  81--
  82`default`, `myers`;;
  83        The basic greedy diff algorithm. Currently, this is the default.
  84`minimal`;;
  85        Spend extra time to make sure the smallest possible diff is
  86        produced.
  87`patience`;;
  88        Use "patience diff" algorithm when generating patches.
  89`histogram`;;
  90        This algorithm extends the patience algorithm to "support
  91        low-occurrence common elements".
  92--
  93+
  94For instance, if you configured diff.algorithm variable to a
  95non-default value and want to use the default one, then you
  96have to use `--diff-algorithm=default` option.
  97
  98--stat[=<width>[,<name-width>[,<count>]]]::
  99        Generate a diffstat. By default, as much space as necessary
 100        will be used for the filename part, and the rest for the graph
 101        part. Maximum width defaults to terminal width, or 80 columns
 102        if not connected to a terminal, and can be overridden by
 103        `<width>`. The width of the filename part can be limited by
 104        giving another width `<name-width>` after a comma. The width
 105        of the graph part can be limited by using
 106        `--stat-graph-width=<width>` (affects all commands generating
 107        a stat graph) or by setting `diff.statGraphWidth=<width>`
 108        (does not affect `git format-patch`).
 109        By giving a third parameter `<count>`, you can limit the
 110        output to the first `<count>` lines, followed by `...` if
 111        there are more.
 112+
 113These parameters can also be set individually with `--stat-width=<width>`,
 114`--stat-name-width=<name-width>` and `--stat-count=<count>`.
 115
 116--numstat::
 117        Similar to `--stat`, but shows number of added and
 118        deleted lines in decimal notation and pathname without
 119        abbreviation, to make it more machine friendly.  For
 120        binary files, outputs two `-` instead of saying
 121        `0 0`.
 122
 123--shortstat::
 124        Output only the last line of the `--stat` format containing total
 125        number of modified files, as well as number of added and deleted
 126        lines.
 127
 128--dirstat[=<param1,param2,...>]::
 129        Output the distribution of relative amount of changes for each
 130        sub-directory. The behavior of `--dirstat` can be customized by
 131        passing it a comma separated list of parameters.
 132        The defaults are controlled by the `diff.dirstat` configuration
 133        variable (see linkgit:git-config[1]).
 134        The following parameters are available:
 135+
 136--
 137`changes`;;
 138        Compute the dirstat numbers by counting the lines that have been
 139        removed from the source, or added to the destination. This ignores
 140        the amount of pure code movements within a file.  In other words,
 141        rearranging lines in a file is not counted as much as other changes.
 142        This is the default behavior when no parameter is given.
 143`lines`;;
 144        Compute the dirstat numbers by doing the regular line-based diff
 145        analysis, and summing the removed/added line counts. (For binary
 146        files, count 64-byte chunks instead, since binary files have no
 147        natural concept of lines). This is a more expensive `--dirstat`
 148        behavior than the `changes` behavior, but it does count rearranged
 149        lines within a file as much as other changes. The resulting output
 150        is consistent with what you get from the other `--*stat` options.
 151`files`;;
 152        Compute the dirstat numbers by counting the number of files changed.
 153        Each changed file counts equally in the dirstat analysis. This is
 154        the computationally cheapest `--dirstat` behavior, since it does
 155        not have to look at the file contents at all.
 156`cumulative`;;
 157        Count changes in a child directory for the parent directory as well.
 158        Note that when using `cumulative`, the sum of the percentages
 159        reported may exceed 100%. The default (non-cumulative) behavior can
 160        be specified with the `noncumulative` parameter.
 161<limit>;;
 162        An integer parameter specifies a cut-off percent (3% by default).
 163        Directories contributing less than this percentage of the changes
 164        are not shown in the output.
 165--
 166+
 167Example: The following will count changed files, while ignoring
 168directories with less than 10% of the total amount of changed files,
 169and accumulating child directory counts in the parent directories:
 170`--dirstat=files,10,cumulative`.
 171
 172--summary::
 173        Output a condensed summary of extended header information
 174        such as creations, renames and mode changes.
 175
 176ifndef::git-format-patch[]
 177--patch-with-stat::
 178        Synonym for `-p --stat`.
 179endif::git-format-patch[]
 180
 181ifndef::git-format-patch[]
 182
 183-z::
 184ifdef::git-log[]
 185        Separate the commits with NULs instead of with new newlines.
 186+
 187Also, when `--raw` or `--numstat` has been given, do not munge
 188pathnames and use NULs as output field terminators.
 189endif::git-log[]
 190ifndef::git-log[]
 191        When `--raw`, `--numstat`, `--name-only` or `--name-status` has been
 192        given, do not munge pathnames and use NULs as output field terminators.
 193endif::git-log[]
 194+
 195Without this option, pathnames with "unusual" characters are quoted as
 196explained for the configuration variable `core.quotePath` (see
 197linkgit:git-config[1]).
 198
 199--name-only::
 200        Show only names of changed files.
 201
 202--name-status::
 203        Show only names and status of changed files. See the description
 204        of the `--diff-filter` option on what the status letters mean.
 205
 206--submodule[=<format>]::
 207        Specify how differences in submodules are shown.  When specifying
 208        `--submodule=short` the 'short' format is used.  This format just
 209        shows the names of the commits at the beginning and end of the range.
 210        When `--submodule` or `--submodule=log` is specified, the 'log'
 211        format is used.  This format lists the commits in the range like
 212        linkgit:git-submodule[1] `summary` does.  When `--submodule=diff`
 213        is specified, the 'diff' format is used.  This format shows an
 214        inline diff of the changes in the submodule contents between the
 215        commit range.  Defaults to `diff.submodule` or the 'short' format
 216        if the config option is unset.
 217
 218--color[=<when>]::
 219        Show colored diff.
 220        `--color` (i.e. without '=<when>') is the same as `--color=always`.
 221        '<when>' can be one of `always`, `never`, or `auto`.
 222ifdef::git-diff[]
 223        It can be changed by the `color.ui` and `color.diff`
 224        configuration settings.
 225endif::git-diff[]
 226
 227--no-color::
 228        Turn off colored diff.
 229ifdef::git-diff[]
 230        This can be used to override configuration settings.
 231endif::git-diff[]
 232        It is the same as `--color=never`.
 233
 234--word-diff[=<mode>]::
 235        Show a word diff, using the <mode> to delimit changed words.
 236        By default, words are delimited by whitespace; see
 237        `--word-diff-regex` below.  The <mode> defaults to 'plain', and
 238        must be one of:
 239+
 240--
 241color::
 242        Highlight changed words using only colors.  Implies `--color`.
 243plain::
 244        Show words as `[-removed-]` and `{+added+}`.  Makes no
 245        attempts to escape the delimiters if they appear in the input,
 246        so the output may be ambiguous.
 247porcelain::
 248        Use a special line-based format intended for script
 249        consumption.  Added/removed/unchanged runs are printed in the
 250        usual unified diff format, starting with a `+`/`-`/` `
 251        character at the beginning of the line and extending to the
 252        end of the line.  Newlines in the input are represented by a
 253        tilde `~` on a line of its own.
 254none::
 255        Disable word diff again.
 256--
 257+
 258Note that despite the name of the first mode, color is used to
 259highlight the changed parts in all modes if enabled.
 260
 261--word-diff-regex=<regex>::
 262        Use <regex> to decide what a word is, instead of considering
 263        runs of non-whitespace to be a word.  Also implies
 264        `--word-diff` unless it was already enabled.
 265+
 266Every non-overlapping match of the
 267<regex> is considered a word.  Anything between these matches is
 268considered whitespace and ignored(!) for the purposes of finding
 269differences.  You may want to append `|[^[:space:]]` to your regular
 270expression to make sure that it matches all non-whitespace characters.
 271A match that contains a newline is silently truncated(!) at the
 272newline.
 273+
 274For example, `--word-diff-regex=.` will treat each character as a word
 275and, correspondingly, show differences character by character.
 276+
 277The regex can also be set via a diff driver or configuration option, see
 278linkgit:gitattributes[5] 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 conflict markers or whitespace errors.
 294        What are 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.
 301
 302--ws-error-highlight=<kind>::
 303        Highlight whitespace errors in the `context`, `old` or `new`
 304        lines of the diff.  Multiple values are separated by comma,
 305        `none` resets previous values, `default` reset the list to
 306        `new` and `all` is a shorthand for `old,new,context`.  When
 307        this option is not given, and the configuration variable
 308        `diff.wsErrorHighlight` is not set, only whitespace errors in
 309        `new` lines are highlighted. The whitespace errors are colored
 310        whith `color.diff.whitespace`.
 311
 312endif::git-format-patch[]
 313
 314--full-index::
 315        Instead of the first handful of characters, show the full
 316        pre- and post-image blob object names on the "index"
 317        line when generating patch format output.
 318
 319--binary::
 320        In addition to `--full-index`, output a binary diff that
 321        can be applied with `git-apply`.
 322
 323--abbrev[=<n>]::
 324        Instead of showing the full 40-byte hexadecimal object
 325        name in diff-raw format output and diff-tree header
 326        lines, show only a partial prefix.  This is
 327        independent of the `--full-index` option above, which controls
 328        the diff-patch output format.  Non default number of
 329        digits can be specified with `--abbrev=<n>`.
 330
 331-B[<n>][/<m>]::
 332--break-rewrites[=[<n>][/<m>]]::
 333        Break complete rewrite changes into pairs of delete and
 334        create. This serves two purposes:
 335+
 336It affects the way a change that amounts to a total rewrite of a file
 337not as a series of deletion and insertion mixed together with a very
 338few lines that happen to match textually as the context, but as a
 339single deletion of everything old followed by a single insertion of
 340everything new, and the number `m` controls this aspect of the -B
 341option (defaults to 60%). `-B/70%` specifies that less than 30% of the
 342original should remain in the result for Git to consider it a total
 343rewrite (i.e. otherwise the resulting patch will be a series of
 344deletion and insertion mixed together with context lines).
 345+
 346When used with -M, a totally-rewritten file is also considered as the
 347source of a rename (usually -M only considers a file that disappeared
 348as the source of a rename), and the number `n` controls this aspect of
 349the -B option (defaults to 50%). `-B20%` specifies that a change with
 350addition and deletion compared to 20% or more of the file's size are
 351eligible for being picked up as a possible source of a rename to
 352another file.
 353
 354-M[<n>]::
 355--find-renames[=<n>]::
 356ifndef::git-log[]
 357        Detect renames.
 358endif::git-log[]
 359ifdef::git-log[]
 360        If generating diffs, detect and report renames for each commit.
 361        For following files across renames while traversing history, see
 362        `--follow`.
 363endif::git-log[]
 364        If `n` is specified, it is a threshold on the similarity
 365        index (i.e. amount of addition/deletions compared to the
 366        file's size). For example, `-M90%` means Git should consider a
 367        delete/add pair to be a rename if more than 90% of the file
 368        hasn't changed.  Without a `%` sign, the number is to be read as
 369        a fraction, with a decimal point before it.  I.e., `-M5` becomes
 370        0.5, and is thus the same as `-M50%`.  Similarly, `-M05` is
 371        the same as `-M5%`.  To limit detection to exact renames, use
 372        `-M100%`.  The default similarity index is 50%.
 373
 374-C[<n>]::
 375--find-copies[=<n>]::
 376        Detect copies as well as renames.  See also `--find-copies-harder`.
 377        If `n` is specified, it has the same meaning as for `-M<n>`.
 378
 379--find-copies-harder::
 380        For performance reasons, by default, `-C` option finds copies only
 381        if the original file of the copy was modified in the same
 382        changeset.  This flag makes the command
 383        inspect unmodified files as candidates for the source of
 384        copy.  This is a very expensive operation for large
 385        projects, so use it with caution.  Giving more than one
 386        `-C` option has the same effect.
 387
 388-D::
 389--irreversible-delete::
 390        Omit the preimage for deletes, i.e. print only the header but not
 391        the diff between the preimage and `/dev/null`. The resulting patch
 392        is not meant to be applied with `patch` or `git apply`; this is
 393        solely for people who want to just concentrate on reviewing the
 394        text after the change. In addition, the output obviously lacks
 395        enough information to apply such a patch in reverse, even manually,
 396        hence the name of the option.
 397+
 398When used together with `-B`, omit also the preimage in the deletion part
 399of a delete/create pair.
 400
 401-l<num>::
 402        The `-M` and `-C` options require O(n^2) processing time where n
 403        is the number of potential rename/copy targets.  This
 404        option prevents rename/copy detection from running if
 405        the number of rename/copy targets exceeds the specified
 406        number.
 407
 408ifndef::git-format-patch[]
 409--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]::
 410        Select only files that are Added (`A`), Copied (`C`),
 411        Deleted (`D`), Modified (`M`), Renamed (`R`), have their
 412        type (i.e. regular file, symlink, submodule, ...) changed (`T`),
 413        are Unmerged (`U`), are
 414        Unknown (`X`), or have had their pairing Broken (`B`).
 415        Any combination of the filter characters (including none) can be used.
 416        When `*` (All-or-none) is added to the combination, all
 417        paths are selected if there is any file that matches
 418        other criteria in the comparison; if there is no file
 419        that matches other criteria, nothing is selected.
 420+
 421Also, these upper-case letters can be downcased to exclude.  E.g.
 422`--diff-filter=ad` excludes added and deleted paths.
 423
 424-S<string>::
 425        Look for differences that change the number of occurrences of
 426        the specified string (i.e. addition/deletion) in a file.
 427        Intended for the scripter's use.
 428+
 429It is useful when you're looking for an exact block of code (like a
 430struct), and want to know the history of that block since it first
 431came into being: use the feature iteratively to feed the interesting
 432block in the preimage back into `-S`, and keep going until you get the
 433very first version of the block.
 434
 435-G<regex>::
 436        Look for differences whose patch text contains added/removed
 437        lines that match <regex>.
 438+
 439To illustrate the difference between `-S<regex> --pickaxe-regex` and
 440`-G<regex>`, consider a commit with the following diff in the same
 441file:
 442+
 443----
 444+    return !regexec(regexp, two->ptr, 1, &regmatch, 0);
 445...
 446-    hit = !regexec(regexp, mf2.ptr, 1, &regmatch, 0);
 447----
 448+
 449While `git log -G"regexec\(regexp"` will show this commit, `git log
 450-S"regexec\(regexp" --pickaxe-regex` will not (because the number of
 451occurrences of that string did not change).
 452+
 453See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more
 454information.
 455
 456--pickaxe-all::
 457        When `-S` or `-G` finds a change, show all the changes in that
 458        changeset, not just the files that contain the change
 459        in <string>.
 460
 461--pickaxe-regex::
 462        Treat the <string> given to `-S` as an extended POSIX regular
 463        expression to match.
 464endif::git-format-patch[]
 465
 466-O<orderfile>::
 467        Control the order in which files appear in the output.
 468        This overrides the `diff.orderFile` configuration variable
 469        (see linkgit:git-config[1]).  To cancel `diff.orderFile`,
 470        use `-O/dev/null`.
 471+
 472The output order is determined by the order of glob patterns in
 473<orderfile>.
 474All files with pathnames that match the first pattern are output
 475first, all files with pathnames that match the second pattern (but not
 476the first) are output next, and so on.
 477All files with pathnames that do not match any pattern are output
 478last, as if there was an implicit match-all pattern at the end of the
 479file.
 480If multiple pathnames have the same rank (they match the same pattern
 481but no earlier patterns), their output order relative to each other is
 482the normal order.
 483+
 484<orderfile> is parsed as follows:
 485+
 486--
 487 - Blank lines are ignored, so they can be used as separators for
 488   readability.
 489
 490 - Lines starting with a hash ("`#`") are ignored, so they can be used
 491   for comments.  Add a backslash ("`\`") to the beginning of the
 492   pattern if it starts with a hash.
 493
 494 - Each other line contains a single pattern.
 495--
 496+
 497Patterns have the same syntax and semantics as patterns used for
 498fnmantch(3) without the FNM_PATHNAME flag, except a pathname also
 499matches a pattern if removing any number of the final pathname
 500components matches the pattern.  For example, the pattern "`foo*bar`"
 501matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
 502
 503ifndef::git-format-patch[]
 504-R::
 505        Swap two inputs; that is, show differences from index or
 506        on-disk file to tree contents.
 507
 508--relative[=<path>]::
 509        When run from a subdirectory of the project, it can be
 510        told to exclude changes outside the directory and show
 511        pathnames relative to it with this option.  When you are
 512        not in a subdirectory (e.g. in a bare repository), you
 513        can name which subdirectory to make the output relative
 514        to by giving a <path> as an argument.
 515endif::git-format-patch[]
 516
 517-a::
 518--text::
 519        Treat all files as text.
 520
 521--ignore-space-at-eol::
 522        Ignore changes in whitespace at EOL.
 523
 524-b::
 525--ignore-space-change::
 526        Ignore changes in amount of whitespace.  This ignores whitespace
 527        at line end, and considers all other sequences of one or
 528        more whitespace characters to be equivalent.
 529
 530-w::
 531--ignore-all-space::
 532        Ignore whitespace when comparing lines.  This ignores
 533        differences even if one line has whitespace where the other
 534        line has none.
 535
 536--ignore-blank-lines::
 537        Ignore changes whose lines are all blank.
 538
 539--inter-hunk-context=<lines>::
 540        Show the context between diff hunks, up to the specified number
 541        of lines, thereby fusing hunks that are close to each other.
 542        Defaults to `diff.interHunkContext` or 0 if the config option
 543        is unset.
 544
 545-W::
 546--function-context::
 547        Show whole surrounding functions of changes.
 548
 549ifndef::git-format-patch[]
 550ifndef::git-log[]
 551--exit-code::
 552        Make the program exit with codes similar to diff(1).
 553        That is, it exits with 1 if there were differences and
 554        0 means no differences.
 555
 556--quiet::
 557        Disable all output of the program. Implies `--exit-code`.
 558endif::git-log[]
 559endif::git-format-patch[]
 560
 561--ext-diff::
 562        Allow an external diff helper to be executed. If you set an
 563        external diff driver with linkgit:gitattributes[5], you need
 564        to use this option with linkgit:git-log[1] and friends.
 565
 566--no-ext-diff::
 567        Disallow external diff drivers.
 568
 569--textconv::
 570--no-textconv::
 571        Allow (or disallow) external text conversion filters to be run
 572        when comparing binary files. See linkgit:gitattributes[5] for
 573        details. Because textconv filters are typically a one-way
 574        conversion, the resulting diff is suitable for human
 575        consumption, but cannot be applied. For this reason, textconv
 576        filters are enabled by default only for linkgit:git-diff[1] and
 577        linkgit:git-log[1], but not for linkgit:git-format-patch[1] or
 578        diff plumbing commands.
 579
 580--ignore-submodules[=<when>]::
 581        Ignore changes to submodules in the diff generation. <when> can be
 582        either "none", "untracked", "dirty" or "all", which is the default.
 583        Using "none" will consider the submodule modified when it either contains
 584        untracked or modified files or its HEAD differs from the commit recorded
 585        in the superproject and can be used to override any settings of the
 586        'ignore' option in linkgit:git-config[1] or linkgit:gitmodules[5]. When
 587        "untracked" is used submodules are not considered dirty when they only
 588        contain untracked content (but they are still scanned for modified
 589        content). Using "dirty" ignores all changes to the work tree of submodules,
 590        only changes to the commits stored in the superproject are shown (this was
 591        the behavior until 1.7.0). Using "all" hides all changes to submodules.
 592
 593--src-prefix=<prefix>::
 594        Show the given source prefix instead of "a/".
 595
 596--dst-prefix=<prefix>::
 597        Show the given destination prefix instead of "b/".
 598
 599--no-prefix::
 600        Do not show any source or destination prefix.
 601
 602--line-prefix=<prefix>::
 603        Prepend an additional prefix to every line of output.
 604
 605--ita-invisible-in-index::
 606        By default entries added by "git add -N" appear as an existing
 607        empty file in "git diff" and a new file in "git diff --cached".
 608        This option makes the entry appear as a new file in "git diff"
 609        and non-existent in "git diff --cached". This option could be
 610        reverted with `--ita-visible-in-index`. Both options are
 611        experimental and could be removed in future.
 612
 613For more detailed explanation on these common options, see also
 614linkgit:gitdiffcore[7].