Provided by: git-core_1.5.6.3-1.1ubuntu2_i386 bug

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
           Generate patch (see section on generating patches).

       -u
           Synonym for "-p".

       -U<n>
           Shorthand for "--unified=<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".

       --stat[=width[,name-width]]
           Generate a diffstat. You can override the default output width for
           80-column terminal by "--stat=width". The width of the filename
           part can be controlled by giving another width to it separated by a
           comma.

       --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.

       --dirstat[=limit]
           Output only the sub-directories that are impacted by a diff, and to
           what degree they are impacted. You can override the default cut-off
           in percent (3) by "--dirstat=limit". If you want to enable
           "cumulative" directory statistics, you can use the "--cumulative"
           flag, which adds up percentages recursively even when they have
           been already reported for a sub-directory.

       --summary
           Output a condensed summary of extended header information such as
           creations, renames and mode changes.

       --patch-with-stat
           Synonym for "-p --stat".

       -z
           NUL-line termination on output. This affects the --raw output field
           terminator. Also output from commands such as "git-log" will be
           delimited with NUL between commits.

       --name-only
           Show only names of changed files.

       --name-status
           Show only names and status of changed files. See the description of
           the --diff-filter option on what the status letters mean.

       --color
           Show colored diff.

       --no-color
           Turn off colored diff, even when the configuration file gives the
           default to color output.

       --color-words
           Show colored word diff, i.e. color words which have changed.

       --no-renames
           Turn off rename detection, even when the configuration file gives
           the default to do so.

       --check
           Warn if changes introduce trailing whitespace or an indent that
           uses a space before a tab. Exits with non-zero status if problems
           are found. Not compatible with --exit-code.

       --full-index
           Instead of the first handful characters, show full object name of
           pre- and post-image blob on the "index" line when generating a
           patch format output.

       --binary
           In addition to --full-index, output "binary diff" that can be
           applied with "git apply".

       --abbrev[=<n>]
           Instead of showing the full 40-byte hexadecimal object name in
           diff-raw format output and diff-tree header lines, show only
           handful hexdigits prefix. This is independent of --full-index
           option above, which controls the diff-patch output format. Non
           default number of digits can be specified with --abbrev=<n>.

       -B
           Break complete rewrite changes into pairs of delete and create.

       -M
           Detect renames.

       -C
           Detect copies as well as renames. See also --find-copies-harder.

       --diff-filter=[ACDMRTUXB*]
           Select only files that are Added (A), Copied (C), Deleted (D),
           Modified (M), Renamed (R), have their type (mode) changed (T), are
           Unmerged (U), are Unknown (X), or have had their pairing Broken
           (B). Any combination of the filter characters may 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.

       --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.

       -l<num>
           -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.

       -S<string>
           Look for differences that contain the change in <string>.

       --pickaxe-all
           When -S finds a change, show all the changes in that changeset, not
           just the files that contain the 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.

       --text
           Treat all files as text.

       -a
           Shorthand for "--text".

       --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.

       -b
           Shorthand for "--ignore-space-change".

       --ignore-all-space
           Ignore whitespace when comparing lines. This ignores differences
           even if one line has whitespace where the other line has none.

       -w
           Shorthand for "--ignore-all-space".

       --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.

       --ignore-submodules
           Ignore changes to submodules in the diff generation.

       --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)[diffcore documentation].

       <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.

OUTPUT FORMAT

       The 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.
       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 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.
       <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 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.  single path, only for "dst"
       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 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>

        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.
       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.

COMBINED DIFF FORMAT

       "git-diff-tree", "git-diff-files" and "git-diff" can take -c or --cc
       option to produce combined diff. For showing a merge commit with "git
       log -p", this is the default 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 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 --c 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.

        3.  It is followed by two-line from-file/to-file header

               --- a/file
               +++ b/file
           Similar to two-line header for traditional unified diff format,
           /dev/null is used to signal created or deleted files.

        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 for
           apply. 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 last file, 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 two 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 with a "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 "git-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".

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 HEAD
           *100644->100664 blob    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.

AUTHOR

       Written by Linus Torvalds <torvalds@osdl.org>

DOCUMENTATION

       Documentation by David Greaves, Junio C Hamano and the git-list
       <git@vger.kernel.org>.

GIT

       Part of the git(1) suite