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GIT-DIFF-INDEX(1)                                     Git Manual                                    GIT-DIFF-INDEX(1)



NAME
       git-diff-index - Compares content and mode of blobs between the index and repository

SYNOPSIS
       git diff-index [-m] [--cached] [<common diff options>] <tree-ish> [<path>...]


DESCRIPTION
       Compares the content and mode of the blobs found via a tree object with the content of the current index and,
       optionally ignoring the stat state of the file on disk. When paths are specified, compares only those named
       paths. Otherwise all entries in the index are compared.

OPTIONS
       -p, -u, --patch
           Generate patch (see section on generating patches).

       -U<n>, --unified=<n>
           Generate diffs with <n> lines of context instead of the usual three. Implies -p.

       --raw
           Generate the raw format. This is the default.

       --patch-with-raw
           Synonym for -p --raw.

       --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.

       --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 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

       --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.

       --dirstat[=<param1,param2,...>]
           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.

       --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, each pathname output will have TAB, LF, double quotes, and backslash characters
           replaced with \t, \n, \", and \\, respectively, and the pathname will be enclosed in double quotes if any
           of those replacements occurred.

           configuration variable.

       --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.

       --word-diff[=<mode>]
           Show a word diff, using the <mode> to delimit changed words. 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.

           The regex can also be set via a diff driver or configuration option, see gitattributes(1) 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.

       --check
           Warn if changes introduce whitespace errors. What are considered whitespace errors is controlled by
           core.whitespace configuration. By default, trailing whitespaces (including lines that solely consist of
           Instead of showing the full 40-byte hexadecimal object name in diff-raw format output and diff-tree header
           lines, show only a partial prefix. This is independent of the --full-index option above, which controls
           the diff-patch output format. 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%.

       -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 nor git apply; this is solely for
           people who want to just concentrate on reviewing the text after the change. In addition, the output
           obviously lack 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 require O(n^2) processing time where n is the number of potential rename/copy
           targets. This option prevents rename/copy detection from running if the number of rename/copy targets
           exceeds the specified number.

       --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 *
           change in <string>.

       --pickaxe-regex
           Make the <string> not a plain string but an extended POSIX regex to match.

       -O<orderfile>
           Output the patch in the order specified in the <orderfile>, which has one shell glob pattern per line.

       -R
           Swap two inputs; that is, show differences from index or on-disk file to tree contents.

       --relative[=<path>]
           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.

       -a, --text
           Treat all files as text.

       --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.

       --inter-hunk-context=<lines>
           Show the context between diff hunks, up to the specified number of lines, thereby fusing hunks that are
           close to each other.

       -W, --function-context
           Show whole surrounding functions of changes.

       --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.

       --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
           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.

       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

       -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


        6. sha1 for "src"; 0{40} if creation or unmerged.

        7. a space.

        8. sha1 for "dst"; 0{40} if creation, unmerged or "look at work tree".

        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

       ·   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), and are the only ones to be so.

       <sha1> is shown as all 0’s if a file is new on the filesystem and it is out of sync with the index.

       Example:

           :100644 100644 5be4a4...... 000000...... M file.c


       When -z option is not used, TAB, LF, and backslash characters in pathnames are represented as \t, \n, and \\,
       respectively.

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
       Example:

           ::100644 100644 100644 fabadb8... cc95eb0... 4866510... MM      describe.c


       Note that combined diff lists only files which were modified from all parents.

GENERATING PATCHES WITH -P
       When "git-diff-index", "git-diff-tree", or "git-diff-files" are run with a -p option, "git diff" without the
       --raw option, or "git log" with the "-p" option, they do not produce the output described above; instead they
       produce a patch file. You can customize the creation of such patches via the GIT_EXTERNAL_DIFF and the
       GIT_DIFF_OPTS environment variables.

       What the -p option produces is slightly different from the traditional diff format:

        1. It is preceded with 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 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 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 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 SHA-1 checksum 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. TAB, LF, double quote and backslash characters in pathnames are represented as \t, \n, \" and \\,
           respectively. If there is need for such substitution then the whole pathname is put in double quotes.


       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
       the `-m’ option to any of these commands to force generation of diffs with individual parents of a merge.

       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 with a "git diff" header, that looks like this (when -c option is used):

               diff --combined file

           or like this (when --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 contents movement (renames and copying detection) are
           designed to work with diff of two <tree-ish> and are not used by combined diff format.

               @@@ <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 nor 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);

        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 blob    4161aecc6700a2eb579e842af0b7f22b98443f74        commit.c
           +100644 blob    4161aecc6700a2eb579e842af0b7f22b98443f74        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".

       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 100664 7476bb... 000000...      kernel/sched.c

       i.e., it shows that the tree has changed, and that kernel/sched.c has 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



Git 1.8.3.1                                           03/23/2016                                    GIT-DIFF-INDEX(1)