GIT-LOG(1)

NAME
git-log - Show commit logs

SYNOPSIS
git log [<options>] [<since>..<until>] [[--] <path>...]

DESCRIPTION
Shows the commit logs.

The command takes options applicable to the git-rev-list command to control what is shown and how, and options applicable to the git-diff-* commands to control how the changes each commit introduces are shown.

OPTIONS

-p, -u
    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.

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

--patience
    Generate a diff using the "patience diff" algorithm.

--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 the distribution of relative amount of changes (number of lines added or removed) for each sub-directory. Directories with changes below a cut-off percent (3% by default) are not shown. The cut-off percent can be set with "--dirstat=limit". Changes in a child directory is not counted for the parent directory, unless "--cumulative" is used.

--dirstat-by-file[=limit]
    Same as --dirstat, but counts changed files instead of lines.

--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[=<regex>]
    Show colored word diff, i.e., color words which have changed. By default, words are separated by whitespace.

    When a <regex> is specified, 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.

--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 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 "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 a partial 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 (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 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 introduce or remove an instance of <string>. Note that this is different than the string simply appearing in diff output; see the pickaxe entry in gitdiffcore(7) for more details.

--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.

-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.

--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).

-<n>
    Limits the number of commits to show.

<since>..<until>
    Show only commits between the named two commits. When either <since> or <until> is omitted, it defaults to HEAD, i.e. the tip of the current branch. For a more complete list of ways to spell <since> and <until>, see "SPECIFYING REVISIONS" section in git-rev-parse(1).

--decorate[=short|full]
    Print out the ref names of any commits that are shown. If short is specified, the ref name prefixes refs/heads/, refs/tags/ and refs/remotes/ will not be printed. If full is specified, the full ref name (including prefix) will be printed. The default option is short.

--source
    Print out the ref name given on the command line by which each commit was reached.

--full-diff
    Without this flag, "git log -p <path>..." shows commits that touch the specified paths, and diffs about the same specified paths. With this, the full diff is shown for commits that touch the specified paths; this means that "<path>..." limits only commits, and doesn't limit diff for those commits.

--follow
    Continue listing the history of a file beyond renames.

--log-size
    Before the log message print out its size in bytes. Intended mainly for porcelain tools consumption. If git is unable to produce a valid value size is set to zero. Note that only message is considered, if also a diff is shown its size is not included.

[--] <path>...
    Show only commits that affect any of the specified paths. To prevent confusion with options and branch names, paths may need to be prefixed with "-- " to separate them from options or refnames.

  Commit Formatting

--pretty[=<format>], --format[=<format>]
    Pretty-print the contents of the commit logs in a given format, where <format> can be one of oneline, short, medium, full, fuller, email, raw and format:<string>. When omitted, the format defaults to medium.

    Note: you can specify the default pretty format in the repository configuration (see git-config(1)).

--abbrev-commit
    Instead of showing the full 40-byte hexadecimal commit object name, show only a partial prefix. Non default number of digits can be specified with "--abbrev=<n>" (which also modifies diff output, if it is displayed).

    This should make "--pretty=oneline" a whole lot more readable for people using 80-column terminals.

--oneline
    This is a shorthand for "--pretty=oneline --abbrev-commit" used together.

--encoding[=<encoding>]
    The commit objects record the encoding used for the log message in their encoding header; this option can be used to tell the command to re-code the commit log message in the encoding preferred by the user. For non plumbing commands this defaults to UTF-8.

--relative-date
    Synonym for --date=relative.

--date={relative,local,default,iso,rfc,short,raw}
    Only takes effect for dates shown in human-readable format, such as when using "--pretty". log.date config variable sets a default value for log command's --date option.

    --date=relative shows dates relative to the current time, e.g. "2 hours ago".

    --date=local shows timestamps in user's local timezone.

    --date=iso (or --date=iso8601) shows timestamps in ISO 8601 format.

    --date=rfc (or --date=rfc2822) shows timestamps in RFC 2822 format, often found in E-mail messages.

    --date=short shows only date but not time, in YYYY-MM-DD format.

    --date=raw shows the date in the internal raw git format %s %z format.

    --date=default shows timestamps in the original timezone (either committer's or author's).

--parents
    Print the parents of the commit. Also enables parent rewriting, see History Simplification below.

--children
    Print the children of the commit. Also enables parent rewriting, see History Simplification below.

--left-right
    Mark which side of a symmetric diff a commit is reachable from. Commits from the left side are prefixed with < and those from the right with >. If combined with --boundary, those commits are prefixed with -.

    For example, if you have this topology:

        .ft C
                     y---b---b  branch B
                    / \ /
                   /   .
                  /   / \
                 o---x---a---a  branch A
        .ft
    you would get an output like this:

        .ft C
                $ git rev-list --left-right --boundary --pretty=oneline A...B
                >bbbbbbb... 3rd on b
                >bbbbbbb... 2nd on b
                <aaaaaaa... 3rd on a
                <aaaaaaa... 2nd on a
                -yyyyyyy... 1st on b
                -xxxxxxx... 1st on a
        .ft

--graph
    Draw a text-based graphical representation of the commit history on the left hand side of the output. This may cause extra lines to be printed in between commits, in order for the graph history to be drawn properly.

    This implies the --topo-order option by default, but the --date-order option may also be specified.

  Diff Formatting
Below are listed options that control the formatting of diff output. Some of them are specific to git-rev-list(1), however other diff options may be given. See git-diff-files(1) for more options.

-c
    This flag changes the way a merge commit is displayed. It shows the differences from each of the parents to the merge result simultaneously instead of showing pairwise diff between a parent and the result one at a time. Furthermore, it lists only files which were modified from all parents.

--cc
    This flag implies the -c options and further compresses the patch output by omitting uninteresting hunks whose contents in the parents have only two variants and the merge result picks one of them without modification.

-r
    Show recursive diffs.

-t
    Show the tree objects in the diff output. This implies -r.

  Commit Limiting
Besides specifying a range of commits that should be listed using the special notations explained in the description, additional commit limiting may be applied.

-n number, --max-count=<number>
    Limit the number of commits output.

--skip=<number>
    Skip number commits before starting to show the commit output.

--since=<date>, --after=<date>
    Show commits more recent than a specific date.

--until=<date>, --before=<date>
    Show commits older than a specific date.

--author=<pattern>, --committer=<pattern>
    Limit the commits output to ones with author/committer header lines that match the specified pattern (regular expression).

--grep=<pattern>
    Limit the commits output to ones with log message that matches the specified pattern (regular expression).

--all-match
    Limit the commits output to ones that match all given --grep, --author and --committer instead of ones that match at least one.

-i, --regexp-ignore-case
    Match the regexp limiting patterns without regard to letters case.

-E, --extended-regexp
    Consider the limiting patterns to be extended regular expressions instead of the default basic regular expressions.

-F, --fixed-strings
    Consider the limiting patterns to be fixed strings (don't interpret pattern as a regular expression).

--remove-empty
    Stop when a given path disappears from the tree.

--merges
    Print only merge commits.

--no-merges
    Do not print commits with more than one parent.

--first-parent
    Follow only the first parent commit upon seeing a merge commit. This option can give a better overview when viewing the evolution of a particular topic branch, because merges into a topic branch tend to be only about adjusting to updated upstream from time to time, and this option allows you to ignore the individual commits brought in to your history by such a merge.

--not
    Reverses the meaning of the ^ prefix (or lack thereof) for all following revision specifiers, up to the next --not.

--all
    Pretend as if all the refs in $GIT_DIR/refs/ are listed on the command line as <commit>.

--branches
    Pretend as if all the refs in $GIT_DIR/refs/heads are listed on the command line as <commit>.

--tags
    Pretend as if all the refs in $GIT_DIR/refs/tags are listed on the command line as <commit>.

--remotes
    Pretend as if all the refs in $GIT_DIR/refs/remotes are listed on the command line as <commit>.

--cherry-pick
    Omit any commit that introduces the same change as another commit on the "other side" when the set of commits are limited with symmetric difference. For example, if you have two branches, A and B, a usual way to list all commits on only one side of them is with --left-right, like the example above in the description of that option. It however shows the commits that were cherry-picked from the other branch (for example, "3rd on b" may be cherry-picked from branch A). With this option, such pairs of commits are excluded from the output.

-g, --walk-reflogs
    Instead of walking the commit ancestry chain, walk reflog entries from the most recent one to older ones. When this option is used you cannot specify commits to exclude (that is, ^commit, commit1..commit2, nor commit1...commit2 notations cannot be used). With --pretty format other than oneline (for obvious reasons), this causes the output to have two extra lines of information taken from the reflog. By default, commit@{Nth} notation is used in the output. When the starting commit is specified as commit@{now}, output also uses commit@{timestamp} notation instead. Under --pretty=oneline, the commit message is prefixed with this information on the same line. This option cannot be combined with --reverse. See also git-reflog(1).

--merge
    After a failed merge, show refs that touch files having a conflict and don't exist on all heads to merge.

--boundary
    Output uninteresting commits at the boundary, which are usually not shown.

  History Simplification
Sometimes you are only interested in parts of the history, for example the commits modifying a particular <path>. But there are two parts of History Simplification, one part is selecting the commits and the other is how to do it, as there are various strategies to simplify the history.

The following options select the commits to be shown:

<paths>
    Commits modifying the given <paths> are selected.

--simplify-by-decoration
    Commits that are referred by some branch or tag are selected.
Note that extra commits can be shown to give a meaningful history.

The following options affect the way the simplification is performed:

Default mode
    Simplifies the history to the simplest history explaining the final state of the tree. Simplest because it prunes some side branches if the end result is the same (i.e. merging branches with the same content)

--full-history
    As the default mode but does not prune some history.

--dense
    Only the selected commits are shown, plus some to have a meaningful history.

--sparse
    All commits in the simplified history are shown.

--simplify-merges
    Additional option to --full-history to remove some needless merges from the resulting history, as there are no selected commits contributing to this merge.
A more detailed explanation follows.

Suppose you specified foo as the <paths>. We shall call commits that modify foo !TREESAME, and the rest TREESAME. (In a diff filtered for foo, they look different and equal, respectively.)

In the following, we will always refer to the same example history to illustrate the differences between simplification settings. We assume that you are filtering for a file foo in this commit graph:

    .ft C
              .-A---M---N---O---P
             /     /   /   /   /
            I     B   C   D   E
             \   /   /   /   /
              `-------------'
    .ft
The horizontal line of history A--P is taken to be the first parent of each merge. The commits are:

    • I is the initial commit, in which foo exists with contents "asdf", and a file quux exists with contents "quux". Initial commits are compared to an empty tree, so I is !TREESAME.

    • In A, foo contains just "foo".

    • B contains the same change as A. Its merge M is trivial and hence TREESAME to all parents.

    • C does not change foo, but its merge N changes it to "foobar", so it is not TREESAME to any parent.

    • D sets foo to "baz". Its merge O combines the strings from N and D to "foobarbaz"; i.e., it is not TREESAME to any parent.

    • E changes quux to "xyzzy", and its merge P combines the strings to "quux xyzzy". Despite appearing interesting, P is TREESAME to all parents.
rev-list walks backwards through history, including or excluding commits based on whether --full-history and/or parent rewriting (via --parents or --children) are used. The following settings are available.

Default mode
    Commits are included if they are not TREESAME to any parent (though this can be changed, see --sparse below). If the commit was a merge, and it was TREESAME to one parent, follow only that parent. (Even if there are several TREESAME parents, follow only one of them.) Otherwise, follow all parents.

    This results in:

        .ft C
                  .-A---N---O
                 /         /
                I---------D
        .ft
    Note how the rule to only follow the TREESAME parent, if one is available, removed B from consideration entirely. C was considered via N, but is TREESAME. Root commits are compared to an empty tree, so I is !TREESAME.

    Parent/child relations are only visible with --parents, but that does not affect the commits selected in default mode, so we have shown the parent lines.

--full-history without parent rewriting
    This mode differs from the default in one point: always follow all parents of a merge, even if it is TREESAME to one of them. Even if more than one side of the merge has commits that are included, this does not imply that the merge itself is! In the example, we get

        .ft C
                I  A  B  N  D  O
        .ft
    P and M were excluded because they are TREESAME to a parent. E, C and B were all walked, but only B was !TREESAME, so the others do not appear.

    Note that without parent rewriting, it is not really possible to talk about the parent/child relationships between the commits, so we show them disconnected.

--full-history with parent rewriting
    Ordinary commits are only included if they are !TREESAME (though this can be changed, see --sparse below).

    Merges are always included. However, their parent list is rewritten: Along each parent, prune away commits that are not included themselves. This results in

        .ft C
                  .-A---M---N---O---P
                 /     /   /   /   /
                I     B   /   D   /
                 \   /   /   /   /
                  `-------------'
        .ft
    Compare to --full-history without rewriting above. Note that E was pruned away because it is TREESAME, but the parent list of P was rewritten to contain E's parent I. The same happened for C and N. Note also that P was included despite being TREESAME.
In addition to the above settings, you can change whether TREESAME affects inclusion:

--dense
    Commits that are walked are included if they are not TREESAME to any parent.

--sparse
    All commits that are walked are included.

    Note that without --full-history, this still simplifies merges: if one of the parents is TREESAME, we follow only that one, so the other sides of the merge are never walked.
Finally, there is a fourth simplification mode available:

--simplify-merges
    First, build a history graph in the same way that --full-history with parent rewriting does (see above).

    Then simplify each commit C to its replacement C' in the final history according to the following rules:

        • Set C' to C.

        • Replace each parent P of C' with its simplification P'. In the process, drop parents that are ancestors of other parents, and remove duplicates.

        • If after this parent rewriting, C' is a root or merge commit (has zero or >1 parents), a boundary commit, or !TREESAME, it remains. Otherwise, it is replaced with its only parent.

        The effect of this is best shown by way of comparing to --full-history with parent rewriting. The example turns into:

        .ft C
                  .-A---M---N---O
                 /     /       /
                I     B       D
                 \   /       /
                  `---------'
        .ft
    Note the major differences in N and P over --full-history:

        • N's parent list had I removed, because it is an ancestor of the other parent M. Still, N remained because it is !TREESAME.

        • P's parent list similarly had I removed. P was then removed completely, because it had one parent and is TREESAME.
The --simplify-by-decoration option allows you to view only the big picture of the topology of the history, by omitting commits that are not referenced by tags. Commits are marked as !TREESAME (in other words, kept after history simplification rules described above) if (1) they are referenced by tags, or (2) they change the contents of the paths given on the command line. All other commits are marked as TREESAME (subject to be simplified away).

  Commit Ordering
By default, the commits are shown in reverse chronological order.

--topo-order
    This option makes them appear in topological order (i.e. descendant commits are shown before their parents).

--date-order
    This option is similar to --topo-order in the sense that no parent comes before all of its children, but otherwise things are still ordered in the commit timestamp order.

--reverse
    Output the commits in reverse order. Cannot be combined with --walk-reflogs.

  Object Traversal
These options are mostly targeted for packing of git repositories.

--objects
    Print the object IDs of any object referenced by the listed commits. --objects foo ^bar thus means "send me all object IDs which I need to download if I have the commit object bar, but not foo".

--objects-edge
    Similar to --objects, but also print the IDs of excluded commits prefixed with a "-" character. This is used by git-pack-objects(1) to build "thin" pack, which records objects in deltified form based on objects contained in these excluded commits to reduce network traffic.

--unpacked
    Only useful with --objects; print the object IDs that are not in packs.

--no-walk
    Only show the given revs, but do not traverse their ancestors.

--do-walk
    Overrides a previous --no-walk.

PRETTY FORMATS
If the commit is a merge, and if the pretty-format is not oneline, email or raw, an additional line is inserted before the Author: line. This line begins with "Merge: " and the sha1s of ancestral commits are printed, separated by spaces. Note that the listed commits may not necessarily be the list of the direct parent commits if you have limited your view of history: for example, if you are only interested in changes related to a certain directory or file.

Here are some additional details for each format:

    • oneline

        <sha1> <title line>
    This is designed to be as compact as possible.

    • short

        commit <sha1>
        Author: <author>

        <title line>

    • medium

        commit <sha1>
        Author: <author>
        Date:   <author date>

        <title line>

        <full commit message>

    • full

        commit <sha1>
        Author: <author>
        Commit: <committer>

        <title line>

        <full commit message>

    • fuller

        commit <sha1>
        Author:     <author>
        AuthorDate: <author date>
        Commit:     <committer>
        CommitDate: <committer date>

        <title line>

        <full commit message>

    • email

        From <sha1> <date>
        From: <author>
        Date: <author date>
        Subject: [PATCH] <title line>

        <full commit message>

    • raw

    The raw format shows the entire commit exactly as stored in the commit object. Notably, the SHA1s are displayed in full, regardless of whether --abbrev or --no-abbrev are used, and parents information show the true parent commits, without taking grafts nor history simplification into account.

    • format:

    The format: format allows you to specify which information you want to show. It works a little bit like printf format, with the notable exception that you get a newline with %n instead of \n.

    E.g, format:"The author of %h was %an, %ar%nThe title was >>%s<<%n" would show something like this:

        .ft C
        The author of fe6e0ee was Junio C Hamano, 23 hours ago
        The title was >>t4119: test autocomputing -p<n> for traditional diff input.<<
        .ft
    The placeholders are:

        • %H: commit hash

        • %h: abbreviated commit hash

        • %T: tree hash

        • %t: abbreviated tree hash

        • %P: parent hashes

        • %p: abbreviated parent hashes

        • %an: author name

        • %aN: author name (respecting .mailmap, see git-shortlog(1) or git-blame(1))

        • %ae: author email

        • %aE: author email (respecting .mailmap, see git-shortlog(1) or git-blame(1))

        • %ad: author date (format respects --date= option)

        • %aD: author date, RFC2822 style

        • %ar: author date, relative

        • %at: author date, UNIX timestamp

        • %ai: author date, ISO 8601 format

        • %cn: committer name

        • %cN: committer name (respecting .mailmap, see git-shortlog(1) or git-blame(1))

        • %ce: committer email

        • %cE: committer email (respecting .mailmap, see git-shortlog(1) or git-blame(1))

        • %cd: committer date

        • %cD: committer date, RFC2822 style

        • %cr: committer date, relative

        • %ct: committer date, UNIX timestamp

        • %ci: committer date, ISO 8601 format

        • %d: ref names, like the --decorate option of git-log(1)

        • %e: encoding

        • %s: subject

        • %f: sanitized subject line, suitable for a filename

        • %b: body

        • %Cred: switch color to red

        • %Cgreen: switch color to green

        • %Cblue: switch color to blue

        • %Creset: reset color

        • %C(...): color specification, as described in color.branch.* config option

        • %m: left, right or boundary mark

        • %n: newline

        • %x00: print a byte from a hex code

    • tformat:

    The tformat: format works exactly like format:, except that it provides "terminator" semantics instead of "separator" semantics. In other words, each commit has the message terminator character (usually a newline) appended, rather than a separator placed between entries. This means that the final entry of a single-line format will be properly terminated with a new line, just as the "oneline" format does. For example:

        .ft C
        $ git log -2 --pretty=format:%h 4da45bef \
          | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
        4da45be
        7134973 -- NO NEWLINE
        $ git log -2 --pretty=tformat:%h 4da45bef \
          | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
        4da45be
        7134973
        .ft
    In addition, any unrecognized string that has a % in it is interpreted as if it has tformat: in front of it. For example, these two are equivalent:

        .ft C
        $ git log -2 --pretty=tformat:%h 4da45bef
        $ git log -2 --pretty=%h 4da45bef
        .ft

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:

    .ft C
    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);
    .ft

    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.

    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 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").

EXAMPLES

git log --no-merges
    Show the whole commit history, but skip any merges

git log v2.6.12.. include/scsi drivers/scsi
    Show all commits since version v2.6.12 that changed any file in the include/scsi or drivers/scsi subdirectories

git log --since="2 weeks ago" -- gitk
    Show the changes during the last two weeks to the file gitk. The "--" is necessary to avoid confusion with the branch named gitk

git log --name-status release..test
    Show the commits that are in the "test" branch but not yet in the "release" branch, along with the list of paths each commit modifies.

git log --follow builtin-rev-list.c
    Shows the commits that changed builtin-rev-list.c, including those commits that occurred before the file was given its present name.

DISCUSSION
At the core level, git is character encoding agnostic.

    • The pathnames recorded in the index and in the tree objects are treated as uninterpreted sequences of non-NUL bytes. What readdir(2) returns are what are recorded and compared with the data git keeps track of, which in turn are expected to be what lstat(2) and creat(2) accepts. There is no such thing as pathname encoding translation.

    • The contents of the blob objects are uninterpreted sequences of bytes. There is no encoding translation at the core level.

    • The commit log messages are uninterpreted sequences of non-NUL bytes.
Although we encourage that the commit log messages are encoded in UTF-8, both the core and git Porcelain are designed not to force UTF-8 on projects. If all participants of a particular project find it more convenient to use legacy encodings, git does not forbid it. However, there are a few things to keep in mind.

    1. git-commit and git-commit-tree issues a warning if the commit log message given to it does not look like a valid UTF-8 string, unless you explicitly say your project uses a legacy encoding. The way to say this is to have i18n.commitencoding in .git/config file, like this:

        .ft C
        [i18n]
                commitencoding = ISO-8859-1
        .ft
    Commit objects created with the above setting record the value of i18n.commitencoding in its encoding header. This is to help other people who look at them later. Lack of this header implies that the commit log message is encoded in UTF-8.

    2. git-log, git-show, git-blame and friends look at the encoding header of a commit object, and try to re-code the log message into UTF-8 unless otherwise specified. You can specify the desired output encoding with i18n.logoutputencoding in .git/config file, like this:

        .ft C
        [i18n]
                logoutputencoding = ISO-8859-1
        .ft
    If you do not have this configuration variable, the value of i18n.commitencoding is used instead.
Note that we deliberately chose not to re-code the commit log message when a commit is made to force UTF-8 at the commit object level, because re-coding to UTF-8 is not necessarily a reversible operation.

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