# git-diff-index

## NAME



           git-diff-index - Compare a tree to the working tree or index
    


## SYNOPSIS



           _git diff-index_ [-m] [--cached] [--merge-base] [<common-diff-options>] <tree-ish> [<path>...]
    


## DESCRIPTION



           Compare the content and mode of the blobs found in a tree object
           with the corresponding tracked files in the working tree, or with
           the corresponding paths in the index. When <path> arguments are
           present, compare only paths matching those patterns. Otherwise all
           tracked files are compared.
    


## OPTIONS



           **-p** , **-u** , **--patch**
               Generate patch (see the section called “GENERATING PATCH TEXT
               WITH -P”).
    
           **-s** , **--no-patch**
               Suppress all output from the diff machinery. Useful for
               commands like **git show** that show the patch by default to
               squelch their output, or to cancel the effect of options like
               **--patch** , **--stat** earlier on the command line in an alias.
    
           **-U** _< n>_, **--unified=**_< n>_
               Generate diffs with _< n>_ lines of context instead of the usual
               three. Implies **--patch**.
    
           **--output=**_< file>_
               Output to a specific file instead of stdout.
    
           **--output-indicator-new=**_< char>_, **--output-indicator-old=**_< char>_,
           **--output-indicator-context=**_< char>_
               Specify the character used to indicate new, old or context
               lines in the generated patch. Normally they are **+** , **-** and ' '
               respectively.
    
           **--raw**
               Generate the diff in raw format. This is the default.
    
           **--patch-with-raw**
               Synonym for **-p --raw**.
    
           **--indent-heuristic**
               Enable the heuristic that shifts diff hunk boundaries to make
               patches easier to read. This is the default.
    
           **--no-indent-heuristic**
               Disable the indent heuristic.
    
           **--minimal**
               Spend extra time to make sure the smallest possible diff is
               produced.
    
           **--patience**
               Generate a diff using the "patience diff" algorithm.
    
           **--histogram**
               Generate a diff using the "histogram diff" algorithm.
    
           **--anchored=**_< text>_
               Generate a diff using the "anchored diff" algorithm.
    
               This option may be specified more than once.
    
               If a line exists in both the source and destination, exists
               only once, and starts with _< text>_, this algorithm attempts to
               prevent it from appearing as a deletion or addition in the
               output. It uses the "patience diff" algorithm internally.
    
           **--diff-algorithm=**(**patience** |**minimal** |**histogram** |**myers**)
               Choose a diff algorithm. The variants are as follows:
    
               **default** , **myers**
                   The basic greedy diff algorithm. Currently, this is the
                   default.
    
               **minimal**
                   Spend extra time to make sure the smallest possible diff
                   is produced.
    
               **patience**
                   Use "patience diff" algorithm when generating patches.
    
               **histogram**
                   This algorithm extends the patience algorithm to "support
                   low-occurrence common elements".
    
               For instance, if you configured the **diff.algorithm** variable to
               a non-default value and want to use the default one, then you
               have to use **--diff-algorithm=default** option.
    
           **--stat**[**=**_< width>_[**,**_< name-width>_[**,**_< count>_]]]
               Generate a diffstat. By default, as much space as necessary
               will be used for the filename part, and the rest for the graph
               part. Maximum width defaults to terminal width, or 80 columns
               if not connected to a terminal, and can be overridden by
               _< width>_. The width of the filename part can be limited by
               giving another width _< name-width>_ after a comma or by setting
               **diff.statNameWidth=**_< name-width>_. The width of the graph part
               can be limited by using **--stat-graph-width=**_< graph-width>_ or by
               setting **diff.statGraphWidth=**_< graph-width>_. Using **--stat** or
               **--stat-graph-width** affects all commands generating a stat
               graph, while setting **diff.statNameWidth** or **diff.statGraphWidth**
               does not affect **git format-patch**. By giving a third parameter
               _< count>_, you can limit the output to the first _< count>_ lines,
               followed by ... if there are more.
    
               These parameters can also be set individually with
               **--stat-width=**_< width>_, **--stat-name-width=**_< name-width>_ and
               **--stat-count=**_< count>_.
    
           **--compact-summary**
               Output a condensed summary of extended header information such
               as file creations or deletions ("new" or "gone", optionally **+l**
               if it’s a symlink) and mode changes (**+x** or **-x** for adding or
               removing executable bit respectively) in diffstat. The
               information is put between the filename part and the graph
               part. Implies **--stat**.
    
           **--numstat**
               Similar to **--stat** , but shows number of added and deleted lines
               in decimal notation and pathname without abbreviation, to make
               it more machine friendly. For binary files, outputs two **-**
               instead of saying **0 0**.
    
           **--shortstat**
               Output only the last line of the **--stat** format containing
               total number of modified files, as well as number of added and
               deleted lines.
    
           **-X**[_< param>_**,**...], **--dirstat**[**=**_< param>_**,**...]
               Output the distribution of relative amount of changes for each
               sub-directory. The behavior of **--dirstat** can be customized by
               passing it a comma separated list of parameters. The defaults
               are controlled by the **diff.dirstat** configuration variable (see
               git-config(1)). The following parameters are available:
    
               **changes**
                   Compute the dirstat numbers by counting the lines that
                   have been removed from the source, or added to the
                   destination. This ignores the amount of pure code
                   movements within a file. In other words, rearranging lines
                   in a file is not counted as much as other changes. This is
                   the default behavior when no parameter is given.
    
               **lines**
                   Compute the dirstat numbers by doing the regular
                   line-based diff analysis, and summing the removed/added
                   line counts. (For binary files, count 64-byte chunks
                   instead, since binary files have no natural concept of
                   lines). This is a more expensive **--dirstat** behavior than
                   the **changes** behavior, but it does count rearranged lines
                   within a file as much as other changes. The resulting
                   output is consistent with what you get from the other
                   **--*stat** options.
    
               **files**
                   Compute the dirstat numbers by counting the number of
                   files changed. Each changed file counts equally in the
                   dirstat analysis. This is the computationally cheapest
                   **--dirstat** behavior, since it does not have to look at the
                   file contents at all.
    
               **cumulative**
                   Count changes in a child directory for the parent
                   directory as well. Note that when using **cumulative** , the
                   sum of the percentages reported may exceed 100%. The
                   default (non-cumulative) behavior can be specified with
                   the **noncumulative** parameter.
    
               _< limit>_
                   An integer parameter specifies a cut-off percent (3% by
                   default). Directories contributing less than this
                   percentage of the changes are not shown in the output.
    
               Example: The following will count changed files, while
               ignoring directories with less than 10% of the total amount of
               changed files, and accumulating child directory counts in the
               parent directories: **--dirstat=files** ,10,cumulative.
    
           **--cumulative**
               Synonym for **--dirstat=cumulative**.
    
           **--dirstat-by-file**[**=**_< param>_**,**...]
               Synonym for **--dirstat=files** ,_< param>_**,**....
    
           **--summary**
               Output a condensed summary of extended header information such
               as creations, renames and mode changes.
    
           **--patch-with-stat**
               Synonym for **-p --stat**.
    
           **-z**
               When **--raw** , **--numstat** , **--name-only** or **--name-status** has been
               given, do not munge pathnames and use NULs as output field
               terminators.
    
               Without this option, pathnames with "unusual" characters are
               quoted as explained for the configuration variable
               **core.quotePath**(see git-config(1)).
    
           **--name-only**
               Show only the name of each changed file in the post-image
               tree. The file names are often encoded in UTF-8. For more
               information see the discussion about encoding in the
               git-log(1) manual page.
    
           **--name-status**
               Show only the name(s) and status of each changed file. See the
               description of the **--diff-filter** option on what the status
               letters mean. Just like **--name-only** the file names are often
               encoded in UTF-8.
    
           **--submodule**[**=**_< format>_]
               Specify how differences in submodules are shown. When
               specifying **--submodule=short** the **short** format is used. This
               format just shows the names of the commits at the beginning
               and end of the range. When **--submodule** or **--submodule=log** is
               specified, the **log** format is used. This format lists the
               commits in the range like git-submodule(1) **summary** does. When
               **--submodule=diff** is specified, the **diff** format is used. This
               format shows an inline diff of the changes in the submodule
               contents between the commit range. Defaults to **diff.submodule**
               or the **short** format if the config option is unset.
    
           **--color**[**=**_< when>_]
               Show colored diff.  **--color**(i.e. without **=**_< when>_) is the same
               as **--color=always**.  _< when>_ can be one of **always** , **never** , or
               **auto**.
    
           **--no-color**
               Turn off colored diff. It is the same as **--color=never**.
    
           **--color-moved**[**=**_< mode>_]
               Moved lines of code are colored differently. The _< mode>_
               defaults to **no** if the option is not given and to **zebra** if the
               option with no mode is given. The mode must be one of:
    
               **no**
                   Moved lines are not highlighted.
    
               **default**
                   Is a synonym for **zebra**. This may change to a more sensible
                   mode in the future.
    
               **plain**
                   Any line that is added in one location and was removed in
                   another location will be colored with **color.diff.newMoved**.
                   Similarly **color.diff.oldMoved** will be used for removed
                   lines that are added somewhere else in the diff. This mode
                   picks up any moved line, but it is not very useful in a
                   review to determine if a block of code was moved without
                   permutation.
    
               **blocks**
                   Blocks of moved text of at least 20 alphanumeric
                   characters are detected greedily. The detected blocks are
                   painted using either the **color.diff.**(**old** |**new**)**Moved** color.
                   Adjacent blocks cannot be told apart.
    
               **zebra**
                   Blocks of moved text are detected as in **blocks** mode. The
                   blocks are painted using either the
                   **color.diff.**(**old** |**new**)**Moved** color or
                   **color.diff.**(**old** |**new**)**MovedAlternative**. The change between
                   the two colors indicates that a new block was detected.
    
               **dimmed-zebra**
                   Similar to **zebra** , but additional dimming of uninteresting
                   parts of moved code is performed. The bordering lines of
                   two adjacent blocks are considered interesting, the rest
                   is uninteresting.  **dimmed_zebra** is a deprecated synonym.
    
           **--no-color-moved**
               Turn off move detection. This can be used to override
               configuration settings. It is the same as **--color-moved=no**.
    
           **--color-moved-ws=**_< mode>_**,**...
               This configures how whitespace is ignored when performing the
               move detection for **--color-moved**. These modes can be given as
               a comma separated list:
    
               **no**
                   Do not ignore whitespace when performing move detection.
    
               **ignore-space-at-eol**
                   Ignore changes in whitespace at EOL.
    
               **ignore-space-change**
                   Ignore changes in amount of whitespace. This ignores
                   whitespace at line end, and considers all other sequences
                   of one or more whitespace characters to be equivalent.
    
               **ignore-all-space**
                   Ignore whitespace when comparing lines. This ignores
                   differences even if one line has whitespace where the
                   other line has none.
    
               **allow-indentation-change**
                   Initially ignore any whitespace in the move detection,
                   then group the moved code blocks only into a block if the
                   change in whitespace is the same per line. This is
                   incompatible with the other modes.
    
           **--no-color-moved-ws**
               Do not ignore whitespace when performing move detection. This
               can be used to override configuration settings. It is the same
               as **--color-moved-ws=no**.
    
           **--word-diff**[**=**_< mode>_]
               By default, words are delimited by whitespace; see
               **--word-diff-regex** below. The _< mode>_ defaults to **plain** , and
               must be one of:
    
               **color**
                   Highlight changed words using only colors. Implies
                   **--color**.
    
               **plain**
                   Show words as **[-removed-]** and **{added**}. Makes no attempts
                   to escape the delimiters if they appear in the input, so
                   the output may be ambiguous.
    
               **porcelain**
                   Use a special line-based format intended for script
                   consumption. Added/removed/unchanged runs are printed in
                   the usual unified diff format, starting with a **+** /**-** /` `
                   character at the beginning of the line and extending to
                   the end of the line. Newlines in the input are represented
                   by a tilde **~** on a line of its own.
    
               **none**
                   Disable word diff again.
    
               Note that despite the name of the first mode, color is used to
               highlight the changed parts in all modes if enabled.
    
           **--word-diff-regex=**_< regex>_
               Use _< regex>_ to decide what a word is, instead of considering
               runs of non-whitespace to be a word. Also implies **--word-diff**
               unless it was already enabled.
    
               Every non-overlapping match of the _< regex>_ is considered a
               word. Anything between these matches is considered whitespace
               and ignored(!) for the purposes of finding differences. You
               may want to append |[**^**[**:space:**]] to your regular expression to
               make sure that it matches all non-whitespace characters. A
               match that contains a newline is silently truncated(!) at the
               newline.
    
               For example, **--word-diff-regex=.** will treat each character as
               a word and, correspondingly, show differences character by
               character.
    
               The regex can also be set via a diff driver or configuration
               option, see gitattributes(5) or git-config(1). Giving it
               explicitly overrides any diff driver or configuration setting.
               Diff drivers override configuration settings.
    
           **--color-words**[**=**_< regex>_]
               Equivalent to **--word-diff=color** plus (if a regex was
               specified) **--word-diff-regex=**_< regex>_.
    
           **--no-renames**
               Turn off rename detection, even when the configuration file
               gives the default to do so.
    
           **--**[**no-**]**rename-empty**
               Whether to use empty blobs as rename source.
    
           **--check**
               Warn if changes introduce conflict markers or whitespace
               errors. What are considered whitespace errors is controlled by
               **core.whitespace** configuration. By default, trailing
               whitespaces (including lines that consist solely of
               whitespaces) and a space character that is immediately
               followed by a tab character inside the initial indent of the
               line are considered whitespace errors. Exits with non-zero
               status if problems are found. Not compatible with **--exit-code**.
    
           **--ws-error-highlight=**_< kind>_
               Highlight whitespace errors in the **context** , **old** or **new** lines
               of the diff. Multiple values are separated by comma, **none**
               resets previous values, **default** reset the list to **new** and **all**
               is a shorthand for **old** ,new,context. When this option is not
               given, and the configuration variable **diff.wsErrorHighlight** is
               not set, only whitespace errors in **new** lines are highlighted.
               The whitespace errors are colored with **color.diff.whitespace**.
    
           **--full-index**
               Instead of the first handful of characters, show the full pre-
               and post-image blob object names on the "index" line when
               generating patch format output.
    
           **--binary**
               In addition to **--full-index** , output a binary diff that can be
               applied with **git-apply**. Implies **--patch**.
    
           **--abbrev**[**=**_< n>_]
               Instead of showing the full 40-byte hexadecimal object name in
               diff-raw format output and diff-tree header lines, show the
               shortest prefix that is at least _< n>_ hexdigits long that
               uniquely refers the object. In diff-patch output format,
               **--full-index** takes higher precedence, i.e. if **--full-index** is
               specified, full blob names will be shown regardless of
               **--abbrev**. Non default number of digits can be specified with
               **--abbrev=**_< n>_.
    
           **-B**[_< n>_][**/**_< m>_], **--break-rewrites**[**=**[_< n>_][**/**_< m>_]]
               Break complete rewrite changes into pairs of delete and
               create. This serves two purposes:
    
               It affects the way a change that amounts to a total rewrite of
               a file not as a series of deletion and insertion mixed
               together with a very few lines that happen to match textually
               as the context, but as a single deletion of everything old
               followed by a single insertion of everything new, and the
               number _< m>_ controls this aspect of the **-B** option (defaults to
               60%).  **-B/70%** specifies that less than 30% of the original
               should remain in the result for Git to consider it a total
               rewrite (i.e. otherwise the resulting patch will be a series
               of deletion and insertion mixed together with context lines).
    
               When used with **-M** , a totally-rewritten file is also considered
               as the source of a rename (usually **-M** only considers a file
               that disappeared as the source of a rename), and the number
               _< n>_ controls this aspect of the **-B** option (defaults to 50%).
               **-B20%** specifies that a change with addition and deletion
               compared to 20% or more of the file’s size are eligible for
               being picked up as a possible source of a rename to another
               file.
    
           **-M**[_< n>_], **--find-renames**[**=**_< n>_]
               Detect renames. If _< n>_ is specified, it is a threshold on the
               similarity index (i.e. amount of addition/deletions compared
               to the file’s size). For example, **-M90%** means Git should
               consider a delete/add pair to be a rename if more than 90% of
               the file hasn’t changed. Without a **%** sign, the number is to be
               read as a fraction, with a decimal point before it. I.e., **-M5**
               becomes 0.5, and is thus the same as **-M50%**. Similarly, **-M05** is
               the same as **-M5%**. To limit detection to exact renames, use
               **-M100%**. The default similarity index is 50%.
    
           **-C**[_< n>_], **--find-copies**[**=**_< n>_]
               Detect copies as well as renames. See also
               **--find-copies-harder**. If _< n>_ is specified, it has the same
               meaning as for **-M** _< n>_.
    
           **--find-copies-harder**
               For performance reasons, by default, **-C** option finds copies
               only if the original file of the copy was modified in the same
               changeset. This flag makes the command inspect unmodified
               files as candidates for the source of copy. This is a very
               expensive operation for large projects, so use it with
               caution. Giving more than one **-C** option has the same effect.
    
           **-D** , **--irreversible-delete**
               Omit the preimage for deletes, i.e. print only the header but
               not the diff between the preimage and **/dev/null**. The resulting
               patch is not meant to be applied with **patch** or **git apply** ; this
               is solely for people who want to just concentrate on reviewing
               the text after the change. In addition, the output obviously
               lacks enough information to apply such a patch in reverse,
               even manually, hence the name of the option.
    
               When used together with **-B** , omit also the preimage in the
               deletion part of a delete/create pair.
    
           **-l** _< num>_
               The **-M** and **-C** options involve some preliminary steps that can
               detect subsets of renames/copies cheaply, followed by an
               exhaustive fallback portion that compares all remaining
               unpaired destinations to all relevant sources. (For renames,
               only remaining unpaired sources are relevant; for copies, all
               original sources are relevant.) For N sources and
               destinations, this exhaustive check is O(N^2). This option
               prevents the exhaustive portion of rename/copy detection from
               running if the number of source/destination files involved
               exceeds the specified number. Defaults to **diff.renameLimit**.
               Note that a value of 0 is treated as unlimited.
    
           **--diff-filter=**[(**A** |**C** |**D** |**M** |**R** |**T** |**U** |**X** |**B**)**...**[*****]]
               Select only files that are Added (**A**), Copied (**C**), Deleted (**D**),
               Modified (**M**), Renamed (**R**), have their type (i.e. regular file,
               symlink, submodule, ...) changed (**T**), are Unmerged (**U**), are
               Unknown (**X**), or have had their pairing Broken (**B**). Any
               combination of the filter characters (including none) can be
               used. When *****(All-or-none) is added to the combination, all
               paths are selected if there is any file that matches other
               criteria in the comparison; if there is no file that matches
               other criteria, nothing is selected.
    
               Also, these upper-case letters can be downcased to exclude.
               E.g.  **--diff-filter=ad** excludes added and deleted paths.
    
               Note that not all diffs can feature all types. For instance,
               copied and renamed entries cannot appear if detection for
               those types is disabled.
    
           **-S** _< string>_
               Look for differences that change the number of occurrences of
               the specified _< string>_ (i.e. addition/deletion) in a file.
               Intended for the scripter’s use.
    
               It is useful when you’re looking for an exact block of code
               (like a struct), and want to know the history of that block
               since it first came into being: use the feature iteratively to
               feed the interesting block in the preimage back into **-S** , and
               keep going until you get the very first version of the block.
    
               Binary files are searched as well.
    
           **-G** _< regex>_
               Look for differences whose patch text contains added/removed
               lines that match _< regex>_.
    
               To illustrate the difference between **-S** _< regex>_ **--pickaxe-regex**
               and **-G** _< regex>_, consider a commit with the following diff in
               the same file:
    
                   +    return frotz(nitfol, two->ptr, 1, 0);
                   ...
                   -    hit = frotz(nitfol, mf2.ptr, 1, 0);
    
               While **git log -G** "frotz\(**nitfol** " will show this commit, **git log**
               **-S** "frotz\(**nitfol** " **--pickaxe-regex** will not (because the number
               of occurrences of that string did not change).
    
               Unless **--text** is supplied patches of binary files without a
               textconv filter will be ignored.
    
               See the _pickaxe_ entry in gitdiffcore(7) for more information.
    
           **--find-object=**_< object-id>_
               Look for differences that change the number of occurrences of
               the specified object. Similar to **-S** , just the argument is
               different in that it doesn’t search for a specific string but
               for a specific object id.
    
               The object can be a blob or a submodule commit. It implies the
               **-t** option in **git-log** to also find trees.
    
           **--pickaxe-all**
               When **-S** or **-G** finds a change, show all the changes in that
               changeset, not just the files that contain the change in
               _< string>_.
    
           **--pickaxe-regex**
               Treat the _< string>_ given to **-S** as an extended POSIX regular
               expression to match.
    
           **-O** _< orderfile>_
               Control the order in which files appear in the output. This
               overrides the **diff.orderFile** configuration variable (see
               git-config(1)). To cancel **diff.orderFile** , use **-O/dev/null**.
    
               The output order is determined by the order of glob patterns
               in _< orderfile>_. All files with pathnames that match the first
               pattern are output first, all files with pathnames that match
               the second pattern (but not the first) are output next, and so
               on. All files with pathnames that do not match any pattern are
               output last, as if there was an implicit match-all pattern at
               the end of the file. If multiple pathnames have the same rank
               (they match the same pattern but no earlier patterns), their
               output order relative to each other is the normal order.
    
               _< orderfile>_ is parsed as follows:
    
               •   Blank lines are ignored, so they can be used as separators
                   for readability.
    
               •   Lines starting with a hash ("#") are ignored, so they can
                   be used for comments. Add a backslash ("**\** ") to the
                   beginning of the pattern if it starts with a hash.
    
               •   Each other line contains a single pattern.
    
               Patterns have the same syntax and semantics as patterns used
               for fnmatch(3) without the **FNM_PATHNAME** flag, except a
               pathname also matches a pattern if removing any number of the
               final pathname components matches the pattern. For example,
               the pattern "**foo*bar** " matches "**fooasdfbar** " and
               "**foo/bar/baz/asdf** " but not "**foobarx** ".
    
           **--skip-to=**_< file>_, **--rotate-to=**_< file>_
               Discard the files before the named _< file>_ from the output
               (i.e.  _skip to_), or move them to the end of the output (i.e.
               _rotate to_). These options were invented primarily for the use
               of the **git difftool** command, and may not be very useful
               otherwise.
    
           **-R**
               Swap two inputs; that is, show differences from index or
               on-disk file to tree contents.
    
           **--relative**[**=**_< path>_], **--no-relative**
               When run from a subdirectory of the project, it can be told to
               exclude changes outside the directory and show pathnames
               relative to it with this option. When you are not in a
               subdirectory (e.g. in a bare repository), you can name which
               subdirectory to make the output relative to by giving a _< path>_
               as an argument.  **--no-relative** can be used to countermand both
               **diff.relative** config option and previous **--relative**.
    
           **-a** , **--text**
               Treat all files as text.
    
           **--ignore-cr-at-eol**
               Ignore carriage-return at the end of line when doing a
               comparison.
    
           **--ignore-space-at-eol**
               Ignore changes in whitespace at EOL.
    
           **-b** , **--ignore-space-change**
               Ignore changes in amount of whitespace. This ignores
               whitespace at line end, and considers all other sequences of
               one or more whitespace characters to be equivalent.
    
           **-w** , **--ignore-all-space**
               Ignore whitespace when comparing lines. This ignores
               differences even if one line has whitespace where the other
               line has none.
    
           **--ignore-blank-lines**
               Ignore changes whose lines are all blank.
    
           **-I** _< regex>_, **--ignore-matching-lines=**_< regex>_
               Ignore changes whose all lines match _< regex>_. This option may
               be specified more than once.
    
           **--inter-hunk-context=**_< number>_
               Show the context between diff hunks, up to the specified
               _< number>_ of lines, thereby fusing hunks that are close to each
               other. Defaults to **diff.interHunkContext** or 0 if the config
               option is unset.
    
           **-W** , **--function-context**
               Show whole function as context lines for each change. The
               function names are determined in the same way as **git diff**
               works out patch hunk headers (see "Defining a custom
               hunk-header" in gitattributes(5)).
    
           **--exit-code**
               Make the program exit with codes similar to diff(1). That is,
               it exits with 1 if there were differences and 0 means no
               differences.
    
           **--quiet**
               Disable all output of the program. Implies **--exit-code**.
               Disables execution of external diff helpers whose exit code is
               not trusted, i.e. their respective configuration option
               **diff.trustExitCode** or **diff.**_< driver>_**.trustExitCode** or
               environment variable **GIT_EXTERNAL_DIFF_TRUST_EXIT_CODE** is
               false.
    
           **--ext-diff**
               Allow an external diff helper to be executed. If you set an
               external diff driver with gitattributes(5), you need to use
               this option with git-log(1) and friends.
    
           **--no-ext-diff**
               Disallow external diff drivers.
    
           **--textconv** , **--no-textconv**
               Allow (or disallow) external text conversion filters to be run
               when comparing binary files. See gitattributes(5) for details.
               Because textconv filters are typically a one-way conversion,
               the resulting diff is suitable for human consumption, but
               cannot be applied. For this reason, textconv filters are
               enabled by default only for git-diff(1) and git-log(1), but
               not for git-format-patch(1) or diff plumbing commands.
    
           **--ignore-submodules**[**=**(**none** |**untracked** |**dirty** |**all**)]
               Ignore changes to submodules in the diff generation.  **all** is
               the default. Using **none** will consider the submodule modified
               when it either contains untracked or modified files or its
               **HEAD** differs from the commit recorded in the superproject and
               can be used to override any settings of the **ignore** option in
               git-config(1) or gitmodules(5). When **untracked** is used
               submodules are not considered dirty when they only contain
               untracked content (but they are still scanned for modified
               content). Using **dirty** ignores all changes to the work tree of
               submodules, only changes to the commits stored in the
               superproject are shown (this was the behavior until 1.7.0).
               Using **all** hides all changes to submodules.
    
           **--src-prefix=**_< prefix>_
               Show the given source _< prefix>_ instead of "a/".
    
           **--dst-prefix=**_< prefix>_
               Show the given destination _< prefix>_ instead of "b/".
    
           **--no-prefix**
               Do not show any source or destination prefix.
    
           **--default-prefix**
               Use the default source and destination prefixes ("a/" and
               "b/"). This overrides configuration variables such as
               **diff.noprefix** , **diff.srcPrefix** , **diff.dstPrefix** , and
               **diff.mnemonicPrefix**(see git-config(1)).
    
           **--line-prefix=**_< prefix>_
               Prepend an additional _< prefix>_ to every line of output.
    
           **--ita-invisible-in-index**
               By default entries added by **git add -N** appear as an existing
               empty file in **git diff** and a new file in **git diff --cached**.
               This option makes the entry appear as a new file in **git diff**
               and non-existent in **git diff --cached**. This option could be
               reverted with **--ita-visible-in-index**. Both options are
               experimental and could be removed in future.
    
           For more detailed explanation on these common options, see also
           gitdiffcore(7).
    
           <tree-ish>
               The id of a tree object to diff against.
    
           --cached
               Do not consider the on-disk file at all.
    
           --merge-base
               Instead of comparing <tree-ish> directly, use the merge base
               between <tree-ish> and HEAD instead. <tree-ish> must be a
               commit.
    
           -m
               By default, files recorded in the index but not checked out
               are reported as deleted. This flag makes _git diff-index_ say
               that all non-checked-out files are up to date.
    


## RAW OUTPUT FORMAT



           The raw output format from **git-diff-index** , **git-diff-tree** ,
           **git-diff-files** and **git diff --raw** are very similar.
    
           These commands all compare two sets of things; what is compared
           differs:
    
           **git-diff-index** _< tree-ish>_
               compares the _< tree-ish>_ and the files on the filesystem.
    
           **git-diff-index --cached** _< tree-ish>_
               compares the _< tree-ish>_ and the index.
    
           **git-diff-tree**[**-r**] _< tree-ish-1> <tree-ish-2>_ [_< pattern>_...]
               compares the trees named by the two arguments.
    
           **git-diff-files**[_< pattern>_...]
               compares the index and the files on the filesystem.
    
           The **git-diff-tree** command begins its output by printing the hash
           of what is being compared. After that, all the commands print one
           output line per changed file.
    
           An output line is formatted this way:
    
               in-place edit  :100644 100644 bcd1234 0123456 M file0
               copy-edit      :100644 100644 abcd123 1234567 C68 file1 file2
               rename-edit    :100644 100644 abcd123 1234567 R86 file1 file3
               create         :000000 100644 0000000 1234567 A file4
               delete         :100644 000000 1234567 0000000 D file5
               unmerged       :000000 000000 0000000 0000000 U file6
    
           That is, from the left to the right:
    
            1. a colon.
    
            2. mode for "src"; 000000 if creation or unmerged.
    
            3. a space.
    
            4. mode for "dst"; 000000 if deletion or unmerged.
    
            5. a space.
    
            6. sha1 for "src"; 0{40} if creation or unmerged.
    
            7. a space.
    
            8. sha1 for "dst"; 0{40} if deletion, unmerged or "work tree out
               of sync with the index".
    
            9. a space.
    
           10. status, followed by optional "score" number.
    
           11. a tab or a NUL when **-z** option is used.
    
           12. path for "src"
    
           13. a tab or a NUL when **-z** option is used; only exists for C or R.
    
           14. path for "dst"; only exists for C or R.
    
           15. an LF or a NUL when **-z** option is used, to terminate the
               record.
    
           Possible status letters are:
    
           •   **A** : addition of a file
    
           •   **C** : copy of a file into a new one
    
           •   **D** : deletion of a file
    
           •   **M** : modification of the contents or mode of a file
    
           •   **R** : renaming of a file
    
           •   **T** : change in the type of the file (regular file, symbolic link
               or submodule)
    
           •   **U** : file is unmerged (you must complete the merge before it can
               be committed)
    
           •   **X** : "unknown" change type (most probably a bug, please report
               it)
    
           Status letters **C** and **R** are always followed by a score (denoting
           the percentage of similarity between the source and target of the
           move or copy). Status letter **M** may be followed by a score
           (denoting the percentage of dissimilarity) for file rewrites.
    
           The sha1 for "dst" is shown as all 0’s if a file on the filesystem
           is out of sync with the index.
    
           Example:
    
               :100644 100644 5be4a4a 0000000 M file.c
    
           Without the **-z** option, pathnames with "unusual" characters are
           quoted as explained for the configuration variable **core.quotePath**
           (see git-config(1)). Using **-z** the filename is output verbatim and
           the line is terminated by a NUL byte.
    


## DIFF FORMAT FOR MERGES



           **git-diff-tree** , **git-diff-files** and **git-diff --raw** can take **-c** or
           **--cc** option to generate diff output also for merge commits. The
           output differs from the format described above in the following
           way:
    
            1. there is a colon for each parent
    
            2. there are more "src" modes and "src" sha1
    
            3. status is concatenated status characters for each parent
    
            4. no optional "score" number
    
            5. tab-separated pathname(s) of the file
    
           For **-c** and **--cc** , only the destination or final path is shown even
           if the file was renamed on any side of history. With
           **--combined-all-paths** , the name of the path in each parent is shown
           followed by the name of the path in the merge commit.
    
           Examples for **-c** and **--cc** without **--combined-all-paths** :
    
               ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM       desc.c
               ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM       bar.sh
               ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR       phooey.c
    
           Examples when **--combined-all-paths** added to either **-c** or **--cc** :
    
               ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM       desc.c  desc.c  desc.c
               ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM       foo.sh  bar.sh  bar.sh
               ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR       fooey.c fuey.c  phooey.c
    
           Note that _combined diff_ lists only files which were modified from
           all parents.
    


## GENERATING PATCH TEXT WITH -P



           Running git-diff(1), git-log(1), git-show(1), git-diff-index(1),
           git-diff-tree(1), or git-diff-files(1) with the **-p** option produces
           patch text. You can customize the creation of patch text via the
           **GIT_EXTERNAL_DIFF** and the **GIT_DIFF_OPTS** environment variables (see
           git(1)), and the **diff** attribute (see gitattributes(5)).
    
           What the **-p** option produces is slightly different from the
           traditional diff format:
    
            1. It is preceded by a "git diff" header that looks like this:
    
                   diff --git a/file1 b/file2
    
               The **a/** and **b/** filenames are the same unless rename/copy is
               involved. Especially, even for a creation or a deletion,
               **/dev/null** is _not_ used in place of the **a/** or **b/** filenames.
    
               When a rename/copy is involved, **file1** and **file2** show the name
               of the source file of the rename/copy and the name of the file
               that the rename/copy produces, respectively.
    
            2. It is followed by one or more extended header lines:
    
                   **old mode** _< mode>_
                   **new mode** _< mode>_
                   **deleted file mode** _< mode>_
                   **new file mode** _< mode>_
                   **copy from** _< path>_
                   **copy to** _< path>_
                   **rename from** _< path>_
                   **rename to** _< path>_
                   **similarity index** _< number>_
                   **dissimilarity index** _< number>_
                   **index** _< hash>_**..**_< hash> <mode>_
    
               File modes _< mode>_ are printed as 6-digit octal numbers
               including the file type and file permission bits.
    
               Path names in extended headers do not include the **a/** and **b/**
               prefixes.
    
               The similarity index is the percentage of unchanged lines, and
               the dissimilarity index is the percentage of changed lines. It
               is a rounded down integer, followed by a percent sign. The
               similarity index value of 100% is thus reserved for two equal
               files, while 100% dissimilarity means that no line from the
               old file made it into the new one.
    
               The index line includes the blob object names before and after
               the change. The _< mode>_ is included if the file mode does not
               change; otherwise, separate lines indicate the old and the new
               mode.
    
            3. Pathnames with "unusual" characters are quoted as explained
               for the configuration variable **core.quotePath**(see
               git-config(1)).
    
            4. All the **file1** files in the output refer to files before the
               commit, and all the **file2** files refer to files after the
               commit. It is incorrect to apply each change to each file
               sequentially. For example, this patch will swap a and b:
    
                   diff --git a/a b/b
                   rename from a
                   rename to b
                   diff --git a/b b/a
                   rename from b
                   rename to a
    
            5. Hunk headers mention the name of the function to which the
               hunk applies. See "Defining a custom hunk-header" in
               gitattributes(5) for details of how to tailor this to specific
               languages.
    


## COMBINED DIFF FORMAT



           Any diff-generating command can take the **-c** or **--cc** option to
           produce a _combined diff_ when showing a merge. This is the default
           format when showing merges with git-diff(1) or git-show(1). Note
           also that you can give suitable **--diff-merges** option to any of
           these commands to force generation of diffs in a specific format.
    
           A "combined diff" format looks like this:
    
               diff --combined describe.c
               index fabadb8,cc95eb0..4866510
               --- a/describe.c
               +++ b/describe.c
               @@@ -98,20 -98,12 +98,20 @@@
                       return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
                 }
    
               - static void describe(char *arg)
                -static void describe(struct commit *cmit, int last_one)
               ++static void describe(char *arg, int last_one)
                 {
                +      unsigned char sha1[20];
                +      struct commit *cmit;
                       struct commit_list *list;
                       static int initialized = 0;
                       struct commit_name *n;
    
                +      if (get_sha1(arg, sha1) < 0)
                +              usage(describe_usage);
                +      cmit = lookup_commit_reference(sha1);
                +      if (!cmit)
                +              usage(describe_usage);
                +
                       if (!initialized) {
                               initialized = 1;
                               for_each_ref(get_name);
    
            1. It is preceded by a "git diff" header, that looks like this
               (when the **-c** option is used):
    
                   diff --combined file
    
               or like this (when the **--cc** option is used):
    
                   diff --cc file
    
            2. It is followed by one or more extended header lines (this
               example shows a merge with two parents):
    
                   **index** _< hash>_**,**_< hash>_**..**_< hash>_
                   **mode** _< mode>_**,**_< mode>_**..**_< mode>_
                   **new file mode** _< mode>_
                   **deleted file mode** _< mode>_**,**_< mode>_
    
               The **mode** _< mode>_**,**_< mode>_**..**_< mode>_ line appears only if at least
               one of the <mode> is different from the rest. Extended headers
               with information about detected content movement (renames and
               copying detection) are designed to work with the diff of two
               _< tree-ish>_ and are not used by combined diff format.
    
            3. It is followed by a two-line from-file/to-file header:
    
                   --- a/file
                   +++ b/file
    
               Similar to the two-line header for the traditional _unified_
               diff format, **/dev/null** is used to signal created or deleted
               files.
    
               However, if the --combined-all-paths option is provided,
               instead of a two-line from-file/to-file, you get an N+1 line
               from-file/to-file header, where N is the number of parents in
               the merge commit:
    
                   --- a/file
                   --- a/file
                   --- a/file
                   +++ b/file
    
               This extended format can be useful if rename or copy detection
               is active, to allow you to see the original name of the file
               in different parents.
    
            4. Chunk header format is modified to prevent people from
               accidentally feeding it to **patch -p1**. Combined diff format was
               created for review of merge commit changes, and was not meant
               to be applied. The change is similar to the change in the
               extended _index_ header:
    
                   @@@ <from-file-range> <from-file-range> <to-file-range> @@@
    
               There are (number of parents + 1) **@** characters in the chunk
               header for combined diff format.
    
           Unlike the traditional _unified_ diff format, which shows two files
           A and B with a single column that has **-**(minus — appears in A but
           removed in B), **+**(plus — missing in A but added to B), or " "
           (space — unchanged) prefix, this format compares two or more files
           file1, file2,... with one file X, and shows how X differs from
           each of fileN. One column for each of fileN is prepended to the
           output line to note how X’s line is different from it.
    
           A **-** character in the column N means that the line appears in fileN
           but it does not appear in the result. A **+** character in the column
           N means that the line appears in the result, and fileN does not
           have that line (in other words, the line was added, from the point
           of view of that parent).
    
           In the above example output, the function signature was changed
           from both files (hence two **-** removals from both file1 and file2,
           plus **++** to mean one line that was added does not appear in either
           file1 or file2). Also, eight other lines are the same from file1
           but do not appear in file2 (hence prefixed with **+**).
    
           When shown by **git diff-tree -c** , it compares the parents of a merge
           commit with the merge result (i.e. file1..fileN are the parents).
           When shown by **git diff-files -c** , it compares the two unresolved
           merge parents with the working tree file (i.e. file1 is stage 2
           aka "our version", file2 is stage 3 aka "their version").
    


## OTHER DIFF FORMATS



           The **--summary** option describes newly added, deleted, renamed and
           copied files. The **--stat** option adds **diffstat**(1) graph to the
           output. These options can be combined with other options, such as
           **-p** , and are meant for human consumption.
    
           When showing a change that involves a rename or a copy, **--stat**
           output formats the pathnames compactly by combining common prefix
           and suffix of the pathnames. For example, a change that moves
           **arch/i386/Makefile** to **arch/x86/Makefile** while modifying 4 lines
           will be shown like this:
    
               arch/{i386 => x86}/Makefile    |   4 +--
    
           The **--numstat** option gives the diffstat(1) information but is
           designed for easier machine consumption. An entry in **--numstat**
           output looks like this:
    
               1       2       README
               3       1       arch/{i386 => x86}/Makefile
    
           That is, from left to right:
    
            1. the number of added lines;
    
            2. a tab;
    
            3. the number of deleted lines;
    
            4. a tab;
    
            5. pathname (possibly with rename/copy information);
    
            6. a newline.
    
           When **-z** output option is in effect, the output is formatted this
           way:
    
               1       2       README NUL
               3       1       NUL arch/i386/Makefile NUL arch/x86/Makefile NUL
    
           That is:
    
            1. the number of added lines;
    
            2. a tab;
    
            3. the number of deleted lines;
    
            4. a tab;
    
            5. a NUL (only exists if renamed/copied);
    
            6. pathname in preimage;
    
            7. a NUL (only exists if renamed/copied);
    
            8. pathname in postimage (only exists if renamed/copied);
    
            9. a NUL.
    
           The extra **NUL** before the preimage path in renamed case is to allow
           scripts that read the output to tell if the current record being
           read is a single-path record or a rename/copy record without
           reading ahead. After reading added and deleted lines, reading up
           to **NUL** would yield the pathname, but if that is **NUL** , the record
           will show two paths.
    


## OPERATING MODES



           You can choose whether you want to trust the index file entirely
           (using the **--cached** flag) or ask the diff logic to show any files
           that don’t match the stat state as being "tentatively changed".
           Both of these operations are very useful indeed.
    


## CACHED MODE



           If **--cached** is specified, it allows you to ask:
    
               show me the differences between HEAD and the current index
               contents (the ones I'd write using 'git write-tree')
    
           For example, let’s say that you have worked on your working
           directory, updated some files in the index and are ready to
           commit. You want to see exactly **what** you are going to commit,
           without having to write a new tree object and compare it that way,
           and to do that, you just do
    
               git diff-index --cached HEAD
    
           Example: let’s say I had renamed **commit.c** to **git-commit.c** , and I
           had done an **update-index** to make that effective in the index file.
           **git diff-files** wouldn’t show anything at all, since the index file
           matches my working directory. But doing a _git diff-index_ does:
    
               torvalds@ppc970:~/git> git diff-index --cached HEAD
               :100644 000000 4161aecc6700a2eb579e842af0b7f22b98443f74 0000000000000000000000000000000000000000 D    commit.c
               :000000 100644 0000000000000000000000000000000000000000 4161aecc6700a2eb579e842af0b7f22b98443f74 A    git-commit.c
    
           You can see easily that the above is a rename.
    
           In fact, **git diff-index --cached should** always be entirely
           equivalent to actually doing a _git write-tree_ and comparing that.
           Except this one is much nicer for the case where you just want to
           check where you are.
    
           So doing a **git diff-index --cached** is basically very useful when
           you are asking yourself "what have I already marked for being
           committed, and what’s the difference to a previous tree".
    


## NON-CACHED MODE



           The "non-cached" mode takes a different approach, and is
           potentially the more useful of the two in that what it does can’t
           be emulated with a _git write-tree_ + _git diff-tree_. Thus that’s the
           default mode. The non-cached version asks the question:
    
               show me the differences between HEAD and the currently checked out
               tree - index contents _and_ files that aren't up to date
    
           which is obviously a very useful question too, since that tells
           you what you **could** commit. Again, the output matches the _git_
           _diff-tree -r_ output to a tee, but with a twist.
    
           The twist is that if some file doesn’t match the index, we don’t
           have a backing store thing for it, and we use the magic "all-zero"
           sha1 to show that. So let’s say that you have edited
           **kernel/sched.c** , but have not actually done a _git update-index_ on
           it yet - there is no "object" associated with the new state, and
           you get:
    
               torvalds@ppc970:~/v2.6/linux> git diff-index --abbrev HEAD
               :100644 100644 7476bb5ba 000000000 M  kernel/sched.c
    
           i.e., it shows that the tree has changed, and that **kernel/sched.c**
           is not up to date and may contain new stuff. The all-zero sha1
           means that to get the real diff, you need to look at the object in
           the working directory directly rather than do an object-to-object
           diff.
    
               **Note**
    
               As with other commands of this type, _git diff-index_ does not
               actually look at the contents of the file at all. So maybe
               **kernel/sched.c** hasn’t actually changed, and it’s just that you
               touched it. In either case, it’s a note that you need to _git_
               _update-index_ it to make the index be in sync.
    
               **Note**
    
               You can have a mixture of files show up as "has been updated"
               and "is still dirty in the working directory" together. You
               can always tell which file is in which state, since the "has
               been updated" ones show a valid sha1, and the "not in sync
               with the index" ones will always have the special all-zero
               sha1.
    


## GIT



           Part of the git(1) suite
    


* * *