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GIT\-LOG

Section: Git Manual (1)
Updated: 11/29/2016
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NAME

git-log - Show commit logs

SYNOPSIS

git log [<options>] [<revision range>] [[--] <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

--follow

: Continue listing the history of a file beyond renames (works only for a single file).

--no-decorate, --decorate[=short|full|auto|no]

: 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. If auto is specified, then if the output is going to a terminal, the ref names are shown as if short were given, otherwise no ref names are shown. The default option is short.

--source

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

--use-mailmap

: Use mailmap file to map author and committer names and email addresses to canonical real names and email addresses. See git-shortlog(1).

--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 doesncqt limit diff for those commits.
Note that this affects all diff-based output types, e.g. those produced by --stat, etc.

--log-size

: Include a line lqlog size <number>rq in the output for each commit, where <number> is the length of that commitcqs message in bytes. Intended to speed up tools that read log messages from git log output by allowing them to allocate space in advance.

-L <start>,<end>:<file>, -L :<funcname>:<file>

Trace the evolution of the line range given by "<start>,<end>" (or the function name regex <funcname>) within the <file>. You may not give any pathspec limiters. This is currently limited to a walk starting from a single revision, i.e., you may only give zero or one positive revision arguments. You can specify this option more than once.

<start> and <end> can take one of these forms:

: * number
If <start> or <end> is a number, it specifies an absolute line number (lines count from 1).

: * /regex/
This form will use the first line matching the given POSIX regex. If <start> is a regex, it will search from the end of the previous -L range, if any, otherwise from the start of file. If <start> is lq^/regex/rq, it will search from the start of file. If <end> is a regex, it will search starting at the line given by <start>.

: * +offset or -offset
This is only valid for <end> and will specify a number of lines before or after the line given by <start>.

If lq:<funcname>rq is given in place of <start> and <end>, it is a regular expression that denotes the range from the first funcname line that matches <funcname>, up to the next funcname line. lq:<funcname>rq searches from the end of the previous -L range, if any, otherwise from the start of file. lq^:<funcname>rq searches from the start of file.

: Show only commits in the specified revision range. When no <revision range> is specified, it defaults to HEAD (i.e. the whole history leading to the current commit). origin..HEAD specifies all the commits reachable from the current commit (i.e. HEAD), but not from origin. For a complete list of ways to spell <revision range>, see the Specifying Ranges section of gitrevisions(7).

[--] <path>...

: Show only commits that are enough to explain how the files that match the specified paths came to be. See History Simplification below for details and other simplification modes.
Paths may need to be prefixed with oq`-- 'cq to separate them from options or the revision range, when confusion arises.

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.

Using more options generally further limits the output (e.g. --since=<date1> limits to commits newer than <date1>, and using it with --grep=<pattern> further limits to commits whose log message has a line that matches <pattern>), unless otherwise noted.

Note that these are applied before commit ordering and formatting options, such as --reverse.

-<number>, -n <number>, --max-count=<number>

: Limit the number of commits to 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). With more than one --author=<pattern>, commits whose author matches any of the given patterns are chosen (similarly for multiple --committer=<pattern>).

--grep-reflog=<pattern>

: Limit the commits output to ones with reflog entries that match the specified pattern (regular expression). With more than one --grep-reflog, commits whose reflog message matches any of the given patterns are chosen. It is an error to use this option unless --walk-reflogs is in use.

--grep=<pattern>

: Limit the commits output to ones with log message that matches the specified pattern (regular expression). With more than one --grep=<pattern>, commits whose message matches any of the given patterns are chosen (but see --all-match).
When --show-notes is in effect, the message from the notes is matched as if it were part of the log message.

--all-match

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

--invert-grep

: Limit the commits output to ones with log message that do not match the pattern specified with --grep=<pattern>.

-i, --regexp-ignore-case

: Match the regular expression limiting patterns without regard to letter case.

--basic-regexp

: Consider the limiting patterns to be basic regular expressions; this is the default.

-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 (doncqt interpret pattern as a regular expression).

--perl-regexp

: Consider the limiting patterns to be Perl-compatible regular expressions. Requires libpcre to be compiled in.

--remove-empty

: Stop when a given path disappears from the tree.

--merges

: Print only merge commits. This is exactly the same as --min-parents=2.

--no-merges

: Do not print commits with more than one parent. This is exactly the same as --max-parents=1.

--min-parents=<number>, --max-parents=<number>, --no-min-parents, --no-max-parents

: Show only commits which have at least (or at most) that many parent commits. In particular, --max-parents=1 is the same as --no-merges, --min-parents=2 is the same as --merges. --max-parents=0 gives all root commits and --min-parents=3 all octopus merges.
--no-min-parents and --no-max-parents reset these limits (to no limit) again. Equivalent forms are --min-parents=0 (any commit has 0 or more parents) and --max-parents=-1 (negative numbers denote no upper limit).

--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. Cannot be combined with --bisect.

--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 refs/ are listed on the command line as <commit>.

--branches[=<pattern>]

: Pretend as if all the refs in refs/heads are listed on the command line as <commit>. If <pattern> is given, limit branches to ones matching given shell glob. If pattern lacks ?, *, or [, /* at the end is implied.

--tags[=<pattern>]

: Pretend as if all the refs in refs/tags are listed on the command line as <commit>. If <pattern> is given, limit tags to ones matching given shell glob. If pattern lacks ?, *, or [, /* at the end is implied.

--remotes[=<pattern>]

: Pretend as if all the refs in refs/remotes are listed on the command line as <commit>. If <pattern> is given, limit remote-tracking branches to ones matching given shell glob. If pattern lacks ?, *, or [, /* at the end is implied.

--glob=<glob-pattern>

: Pretend as if all the refs matching shell glob <glob-pattern> are listed on the command line as <commit>. Leading refs/, is automatically prepended if missing. If pattern lacks ?, *, or [, /* at the end is implied.

--exclude=<glob-pattern>

: Do not include refs matching <glob-pattern> that the next --all, --branches, --tags, --remotes, or --glob would otherwise consider. Repetitions of this option accumulate exclusion patterns up to the next --all, --branches, --tags, --remotes, or --glob option (other options or arguments do not clear accumulated patterns).
The patterns given should not begin with refs/heads, refs/tags, or refs/remotes when applied to --branches, --tags, or --remotes, respectively, and they must begin with refs/ when applied to --glob or --all. If a trailing /* is intended, it must be given explicitly.

--reflog

: Pretend as if all objects mentioned by reflogs are listed on the command line as <commit>.

--ignore-missing

: Upon seeing an invalid object name in the input, pretend as if the bad input was not given.

--bisect

: Pretend as if the bad bisection ref refs/bisect/bad was listed and as if it was followed by --not and the good bisection refs refs/bisect/good-* on the command line. Cannot be combined with --first-parent.

--stdin

: In addition to the <commit> listed on the command line, read them from the standard input. If a -- separator is seen, stop reading commits and start reading paths to limit the result.

--cherry-mark

: Like --cherry-pick (see below) but mark equivalent commits with = rather than omitting them, and inequivalent ones with +.

--cherry-pick

: Omit any commit that introduces the same change as another commit on the lqother siderq 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 (see the example below in the description of the --left-right option). However, it shows the commits that were cherry-picked from the other branch (for example, lq3rd on brq may be cherry-picked from branch A). With this option, such pairs of commits are excluded from the output.

--left-only, --right-only

: List only commits on the respective side of a symmetric difference, i.e. only those which would be marked < resp. > by --left-right.
For example, --cherry-pick --right-only A...B omits those commits from B which are in A or are patch-equivalent to a commit in A. In other words, this lists the + commits from git cherry A B. More precisely, --cherry-pick --right-only --no-merges gives the exact list.

--cherry

: A synonym for --right-only --cherry-mark --no-merges; useful to limit the output to the commits on our side and mark those that have been applied to the other side of a forked history with git log --cherry upstream...mybranch, similar to git cherry upstream mybranch.

-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, and 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. The reflog designator in the output may be shown as ref@{Nth} (where Nth is the reverse-chronological index in the reflog) or as ref@{timestamp} (with the timestamp for that entry), depending on a few rules:

: 1. If the starting point is specified as ref@{Nth}, show the index format.

: 2. If the starting point was specified as ref@{now}, show the timestamp format.

: 3. If neither was used, but --date was given on the command line, show the timestamp in the format requested by --date.

: 4. Otherwise, show the index format.

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 doncqt exist on all heads to merge.

--boundary

: Output excluded boundary commits. Boundary commits are prefixed with -.

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

: Same 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.

--ancestry-path

: When given a range of commits to display (e.g. commit1..commit2 or commit2 ^commit1), only display commits that exist directly on the ancestry chain between the commit1 and commit2, i.e. commits that are both descendants of commit1, and ancestors of commit2.

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:

          .-A---M---N---O---P---Q
         /     /   /   /   /   /
        I     B   C   D   E   Y
         \   /   /   /   /   /
          `-------------'   X

The horizontal line of history A---Q is taken to be the first parent of each merge. The commits are:

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

: * In A, foo contains just lqfoorq.

: * 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 lqfoobarrq, so it is not TREESAME to any parent.

: * D sets foo to lqbazrq. Its merge O combines the strings from N and D to lqfoobarbazrq; i.e., it is not TREESAME to any parent.

: * E changes quux to lqxyzzyrq, and its merge P combines the strings to lqquux xyzzyrq. P is TREESAME to O, but not to E.

: * X is an independent root commit that added a new file side, and Y modified it. Y is TREESAME to X. Its merge Q added side to P, and Q is TREESAME to P, but not to Y.

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:

          .-A---N---O
         /     /   /
        I---------D

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

        I  A  B  N  D  O  P  Q

M was excluded because it is TREESAME to both parents. 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

          .-A---M---N---O---P---Q
         /     /   /   /   /
        I     B   /   D   /
         \   /   /   /   /
          `-------------'

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, and X, Y and Q.

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.

--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 or that are root commits TREESAME to an empty tree, and remove duplicates, but take care to never drop all parents that we are TREESAME to.

: * 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:

          .-A---M---N---O
         /     /       /
        I     B       D
         \   /       /
          `---------'

Note the major differences in N, P, and Q 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.

: * Q's parent list had Y simplified to X. X was then removed, because it was a TREESAME root. Q was then removed completely, because it had one parent and is TREESAME.

Finally, there is a fifth simplification mode available:

--ancestry-path

Limit the displayed commits to those directly on the ancestry chain between the lqfromrq and lqtorq commits in the given commit range. I.e. only display commits that are ancestor of the lqtorq commit and descendants of the lqfromrq commit.

As an example use case, consider the following commit history:

            D---E-------F
           /     \       \
          B---C---G---H---I---J
         /                     \
        A-------K---------------L--M

A regular D..M computes the set of commits that are ancestors of M, but excludes the ones that are ancestors of D. This is useful to see what happened to the history leading to M since D, in the sense that lqwhat does M have that did not exist in Drq. The result in this example would be all the commits, except A and B (and D itself, of course).

When we want to find out what commits in M are contaminated with the bug introduced by D and need fixing, however, we might want to view only the subset of D..M that are actually descendants of D, i.e. excluding C and K. This is exactly what the --ancestry-path option does. Applied to the D..M range, it results in:

                E-------F
                 \       \
                  G---H---I---J
                               \
                                L--M

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.

--date-order

: Show no parents before all of its children are shown, but otherwise show commits in the commit timestamp order.

--author-date-order

: Show no parents before all of its children are shown, but otherwise show commits in the author timestamp order.

--topo-order

Show no parents before all of its children are shown, and avoid showing commits on multiple lines of history intermixed.

For example, in a commit history like this:

    ---1----2----4----7
        \              \
         3----5----6----8---

where the numbers denote the order of commit timestamps, git rev-list and friends with --date-order show the commits in the timestamp order: 8 7 6 5 4 3 2 1.

With --topo-order, they would show 8 6 5 3 7 4 2 1 (or 8 7 4 2 6 5 3 1); some older commits are shown before newer ones in order to avoid showing the commits from two parallel development track mixed together.

--reverse

: Output the commits chosen to be shown (see Commit Limiting section above) in reverse order. Cannot be combined with --walk-reflogs.

Object Traversal

These options are mostly targeted for packing of Git repositories.

--no-walk[=(sorted|unsorted)]

: Only show the given commits, but do not traverse their ancestors. This has no effect if a range is specified. If the argument unsorted is given, the commits are shown in the order they were given on the command line. Otherwise (if sorted or no argument was given), the commits are shown in reverse chronological order by commit time. Cannot be combined with --graph.

--do-walk

: Overrides a previous --no-walk.

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, format:<string> and tformat:<string>. When <format> is none of the above, and has %placeholder in it, it acts as if --pretty=tformat:<format> were given.

See the "PRETTY FORMATS" section for some additional details for each format. When =<format> part is omitted, it 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.

--no-abbrev-commit

: Show the full 40-byte hexadecimal commit object name. This negates --abbrev-commit and those options which imply it such as "--oneline". It also overrides the log.abbrevCommit variable.

--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. Note that if an object claims to be encoded in X and we are outputting in X, we will output the object verbatim; this means that invalid sequences in the original commit may be copied to the output.

--expand-tabs=<n>, --expand-tabs, --no-expand-tabs

: Perform a tab expansion (replace each tab with enough spaces to fill to the next display column that is multiple of <n>) in the log message before showing it in the output. --expand-tabs is a short-hand for --expand-tabs=8, and --no-expand-tabs is a short-hand for --expand-tabs=0, which disables tab expansion.
By default, tabs are expanded in pretty formats that indent the log message by 4 spaces (i.e. medium, which is the default, full, and fuller).

--notes[=<treeish>]

Show the notes (see git-notes(1)) that annotate the commit, when showing the commit log message. This is the default for git log, git show and git whatchanged commands when there is no --pretty, --format, or --oneline option given on the command line.

By default, the notes shown are from the notes refs listed in the core.notesRef and notes.displayRef variables (or corresponding environment overrides). See git-config(1) for more details.

With an optional <treeish> argument, use the treeish to find the notes to display. The treeish can specify the full refname when it begins with refs/notes/; when it begins with notes/, refs/ and otherwise refs/notes/ is prefixed to form a full name of the ref.

Multiple --notes options can be combined to control which notes are being displayed. Examples: "--notes=foo" will show only notes from "refs/notes/foo"; "--notes=foo --notes" will show both notes from "refs/notes/foo" and from the default notes ref(s).

--no-notes

: Do not show notes. This negates the above --notes option, by resetting the list of notes refs from which notes are shown. Options are parsed in the order given on the command line, so e.g. "--notes --notes=foo --no-notes --notes=bar" will only show notes from "refs/notes/bar".

--show-notes[=<treeish>], --[no-]standard-notes

: These options are deprecated. Use the above --notes/--no-notes options instead.

--show-signature

: Check the validity of a signed commit object by passing the signature to gpg --verify and show the output.

--relative-date

: Synonym for --date=relative.

--date=<format>

Only takes effect for dates shown in human-readable format, such as when using --pretty. log.date config variable sets a default value for the log commandcqs --date option. By default, dates are shown in the original time zone (either committercqs or authorcqs). If -local is appended to the format (e.g., iso-local), the usercqs local time zone is used instead.

--date=relative shows dates relative to the current time, e.g. lq2 hours agorq. The -local option has no effect for --date=relative.

--date=local is an alias for --date=default-local.

--date=iso (or --date=iso8601) shows timestamps in a ISO 8601-like format. The differences to the strict ISO 8601 format are:

: * a space instead of the T date/time delimiter

: * a space between time and time zone

: * no colon between hours and minutes of the time zone

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

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

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

--date=raw shows the date as seconds since the epoch (1970-01-01 00:00:00 UTC), followed by a space, and then the timezone as an offset from UTC (a + or - with four digits; the first two are hours, and the second two are minutes). I.e., as if the timestamp were formatted with strftime("%s %z")). Note that the -local option does not affect the seconds-since-epoch value (which is always measured in UTC), but does switch the accompanying timezone value.

--date=unix shows the date as a Unix epoch timestamp (seconds since 1970). As with --raw, this is always in UTC and therefore -local has no effect.

--date=format:... feeds the format ... to your system strftime. Use --date=format:%c to show the date in your system localecqs preferred format. See the strftime manual for a complete list of format placeholders. When using -local, the correct syntax is --date=format-local:....

--date=default is the default format, and is similar to --date=rfc2822, with a few exceptions:

: * there is no comma after the day-of-week

: * the time zone is omitted when the local time zone is used

--parents

: Print also the parents of the commit (in the form "commit parent..."). Also enables parent rewriting, see History Simplification below.

--children

: Print also the children of the commit (in the form "commit child..."). Also enables parent rewriting, see History Simplification below.

--left-right

Mark which side of a symmetric difference 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:

             y---b---b  branch B
            / \ /
           /   .
          /   / \
         o---x---a---a  branch A

you would get an output like this:

        $ 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

--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. Cannot be combined with --no-walk.

This enables parent rewriting, see History Simplification below.

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

--show-linear-break[=<barrier>]

: When --graph is not used, all history branches are flattened which can make it hard to see that the two consecutive commits do not belong to a linear branch. This option puts a barrier in between them in that case. If <barrier> is specified, it is the string that will be shown instead of the default one.

Diff Formatting

Listed below are 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

: With this option, diff output for a merge commit 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 option 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.

-m

: This flag makes the merge commits show the full diff like regular commits; for each merge parent, a separate log entry and diff is generated. An exception is that only diff against the first parent is shown when --first-parent option is given; in that case, the output represents the changes the merge brought into the then-current branch.

-r

: Show recursive diffs.

-t

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

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.

There are several built-in formats, and you can define additional formats by setting a pretty.<name> config option to either another format name, or a format: string, as described below (see git-config(1)). Here are the details of the built-in formats:

* 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 SHA-1s are displayed in full, regardless of whether --abbrev or --no-abbrev are used, and parents information show the true parent commits, without taking grafts or history simplification into account. Note that this format affects the way commits are displayed, but not the way the diff is shown e.g. with git log --raw. To get full object names in a raw diff format, use --no-abbrev.

* format:<string>

The format:<string> 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:

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

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-like format

: * %aI: author date, strict 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 (format respects --date= option)

: * %cD: committer date, RFC2822 style

: * %cr: committer date, relative

: * %ct: committer date, UNIX timestamp

: * %ci: committer date, ISO 8601-like format

: * %cI: committer date, strict ISO 8601 format

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

: * %D: ref names without the " (", ")" wrapping.

: * %e: encoding

: * %s: subject

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

: * %b: body

: * %B: raw body (unwrapped subject and body)

: * %N: commit notes

: * %GG: raw verification message from GPG for a signed commit

: * %G?: show "G" for a good (valid) signature, "B" for a bad signature, "U" for a good signature with unknown validity, "X" for a good signature that has expired, "Y" for a good signature made by an expired key, "R" for a good signature made by a revoked key, "E" if the signature cannot be checked (e.g. missing key) and "N" for no signature

: * %GS: show the name of the signer for a signed commit

: * %GK: show the key used to sign a signed commit

: * %gD: reflog selector, e.g., refs/stash@{1} or refs/stash@{2 minutes ago}; the format follows the rules described for the -g option. The portion before the @ is the refname as given on the command line (so git log -g refs/heads/master would yield refs/heads/master@{0}).

: * %gd: shortened reflog selector; same as %gD, but the refname portion is shortened for human readability (so refs/heads/master becomes just master).

: * %gn: reflog identity name

: * %gN: reflog identity name (respecting .mailmap, see git-shortlog(1) or git-blame(1))

: * %ge: reflog identity email

: * %gE: reflog identity email (respecting .mailmap, see git-shortlog(1) or git-blame(1))

: * %gs: reflog subject

: * %Cred: switch color to red

: * %Cgreen: switch color to green

: * %Cblue: switch color to blue

: * %Creset: reset color

: * %C(...): color specification, as described under Values in the "CONFIGURATION FILE" section of git-config(1); adding auto, at the beginning will emit color only when colors are enabled for log output (by color.diff, color.ui, or --color, and respecting the auto settings of the former if we are going to a terminal). auto alone (i.e. %C(auto)) will turn on auto coloring on the next placeholders until the color is switched again.

: * %m: left (<), right (>) or boundary (-) mark

: * %n: newline

: * %%: a raw %

: * %x00: print a byte from a hex code

: * %w([<w>[,<i1>[,<i2>]]]): switch line wrapping, like the -w option of git-shortlog(1).

: * %<(<N>[,trunc|ltrunc|mtrunc]): make the next placeholder take at least N columns, padding spaces on the right if necessary. Optionally truncate at the beginning (ltrunc), the middle (mtrunc) or the end (trunc) if the output is longer than N columns. Note that truncating only works correctly with N >= 2.

: * %<|(<N>): make the next placeholder take at least until Nth columns, padding spaces on the right if necessary

: * %>(<N>), %>|(<N>): similar to %<(<N>), %<|(<N>) respectively, but padding spaces on the left

: * %>>(<N>), %>>|(<N>): similar to %>(<N>), %>|(<N>) respectively, except that if the next placeholder takes more spaces than given and there are spaces on its left, use those spaces

: * %><(<N>), %><|(<N>): similar to % <(<N>), %<|(<N>) respectively, but padding both sides (i.e. the text is centered)

Note

Some placeholders may depend on other options given to the revision traversal engine. For example, the %g* reflog options will insert an empty string unless we are traversing reflog entries (e.g., by git log -g). The %d and %D placeholders will use the "short" decoration format if --decorate was not already provided on the command line.

If you add a + (plus sign) after % of a placeholder, a line-feed is inserted immediately before the expansion if and only if the placeholder expands to a non-empty string.

If you add a - (minus sign) after % of a placeholder, line-feeds that immediately precede the expansion are deleted if and only if the placeholder expands to an empty string.

If you add a ` ` (space) after % of a placeholder, a space is inserted immediately before the expansion if and only if the placeholder expands to a non-empty string.

* 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:

$ 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

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:

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

COMMON DIFF OPTIONS

-p, -u, --patch

: Generate patch (see section on generating patches).

-s, --no-patch

: Suppress diff output. Useful for commands like git show that show the patch by default, or to cancel the effect of --patch.

-U<n>, --unified=<n>

: Generate diffs with <n> lines of context instead of the usual three. Implies -p.

--raw

: For each commit, show a summary of changes using the raw diff format. See the "RAW OUTPUT FORMAT" section of git-diff(1). This is different from showing the log itself in raw format, which you can achieve with --format=raw.

--patch-with-raw

: Synonym for -p --raw.

--indent-heuristic, --no-indent-heuristic, --compaction-heuristic, --no-compaction-heuristic

: These are to help debugging and tuning experimental heuristics (which are off by default) that shift diff hunk boundaries to make patches easier to read.

--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 another width <name-width> after a comma. The width of the graph part can be limited by using --stat-graph-width=<width> (affects all commands generating a stat graph) or by setting diff.statGraphWidth=<width> (does not affect git format-patch). By giving a third parameter <count>, you can limit the output to the first <count> lines, followed by ... if there are more.
These parameters can also be set individually with --stat-width=<width>, --stat-name-width=<name-width> and --stat-count=<count>.

--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[=<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

Separate the commits with NULs instead of with new newlines.

Also, when --raw or --numstat 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.

--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.

--submodule[=<format>]

: Specify how differences in submodules are shown. When specifying --submodule=short the short format is used. This format just shows the names of the commits at the beginning and end of the range. When --submodule or --submodule=log is specified, the log format is used. This format lists the commits in the range like git-submodule(1)summary does. When --submodule=diff is specified, the diff format is used. This format shows an inline diff of the changes in the submodule contents between the commit range. Defaults to diff.submodule or the short format if the config option is unset.

--color[=<when>]

: Show colored diff. --color (i.e. without =<when>) is the same as --color=always. <when> can be one of always, never, or auto.

--no-color

: Turn off colored diff. It is the same as --color=never.

--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.

For example, --word-diff-regex=. will treat each character as a word and, correspondingly, show differences character by character.

The regex can also be set via a diff driver or configuration option, see gitattributes(5) or git-config(1). Giving it explicitly overrides any diff driver or configuration setting. Diff drivers override configuration settings.

--color-words[=<regex>]

: Equivalent to --word-diff=color plus (if a regex was specified) --word-diff-regex=<regex>.

--no-renames

: Turn off rename detection, even when the configuration file gives the default to do so.

--check

: Warn if changes introduce conflict markers or whitespace errors. What are considered whitespace errors is controlled by core.whitespace configuration. By default, trailing whitespaces (including lines that solely consist of whitespaces) and a space character that is immediately followed by a tab character inside the initial indent of the line are considered whitespace errors. Exits with non-zero status if problems are found. Not compatible with --exit-code.

--ws-error-highlight=<kind>

: Highlight whitespace errors on lines specified by <kind> in the color specified by color.diff.whitespace. <kind> is a comma separated list of old, new, context. When this option is not given, only whitespace errors in new lines are highlighted. E.g. --ws-error-highlight=new,old highlights whitespace errors on both deleted and added lines. all can be used as a short-hand for old,new,context. The diff.wsErrorHighlight configuration variable can be used to specify the default behaviour.

--full-index

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

--binary

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

--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 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 filecqs size are eligible for being picked up as a possible source of a rename to another file.

-M[<n>], --find-renames[=<n>]

: If generating diffs, detect and report renames for each commit. For following files across renames while traversing history, see --follow. If n is specified, it is a threshold on the similarity index (i.e. amount of addition/deletions compared to the filecqs size). For example, -M90% means Git should consider a delete/add pair to be a rename if more than 90% of the file hasncqt changed. Without a % sign, the number is to be read as a fraction, with a decimal point before it. I.e., -M5 becomes 0.5, and is thus the same as -M50%. Similarly, -M05 is the same as -M5%. To limit detection to exact renames, use -M100%. The default similarity index is 50%.

-C[<n>], --find-copies[=<n>]

: Detect copies as well as renames. See also --find-copies-harder. If n is specified, it has the same meaning as for -M<n>.

--find-copies-harder

: For performance reasons, by default, -C option finds copies only if the original file of the copy was modified in the same changeset. This flag makes the command inspect unmodified files as candidates for the source of copy. This is a very expensive operation for large projects, so use it with caution. Giving more than one -C option has the same effect.

-D, --irreversible-delete

: Omit the preimage for deletes, i.e. print only the header but not the diff between the preimage and /dev/null. The resulting patch is not meant to be applied with patch or git apply; this is solely for people who want to just concentrate on reviewing the text after the change. In addition, the output obviously 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 * (All-or-none) is added to the combination, all paths are selected if there is any file that matches other criteria in the comparison; if there is no file that matches other criteria, nothing is selected.
Also, these upper-case letters can be downcased to exclude. E.g. --diff-filter=ad excludes added and deleted paths.

-S<string>

: Look for differences that change the number of occurrences of the specified string (i.e. addition/deletion) in a file. Intended for the scriptercqs use.
It is useful when youcqre looking for an exact block of code (like a struct), and want to know the history of that block since it first came into being: use the feature iteratively to feed the interesting block in the preimage back into -S, and keep going until you get the very first version of the block.

-G<regex>

Look for differences whose patch text contains added/removed lines that match <regex>.

To illustrate the difference between -S<regex> --pickaxe-regex and -G<regex>, consider a commit with the following diff in the same file:

+    return !regexec(regexp, two->ptr, 1, &regmatch, 0);
...
-    hit = !regexec(regexp, mf2.ptr, 1, &regmatch, 0);

While git log -G"regexec\(regexp" will show this commit, git log -S"regexec\(regexp" --pickaxe-regex will not (because the number of occurrences of that string did not change).

See the pickaxe entry in gitdiffcore(7) for more information.

--pickaxe-all

: When -S or -G finds a change, show all the changes in that changeset, not just the files that contain the change in <string>.

--pickaxe-regex

: Treat the <string> given to -S as an extended POSIX regular expression to match.

-O<orderfile>

: Output the patch in the order specified in the <orderfile>, which has one shell glob pattern per line. This overrides the diff.orderFile configuration variable (see git-config(1)). To cancel diff.orderFile, use -O/dev/null.

-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.

--ignore-blank-lines

: Ignore changes whose lines are all blank.

--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.

--ext-diff

: Allow an external diff helper to be executed. If you set an external diff driver with gitattributes(5), you need to use this option with git-log(1) and friends.

--no-ext-diff

: Disallow external diff drivers.

--textconv, --no-textconv

: Allow (or disallow) external text conversion filters to be run when comparing binary files. See gitattributes(5) for details. Because textconv filters are typically a one-way conversion, the resulting diff is suitable for human consumption, but cannot be applied. For this reason, textconv filters are enabled by default only for git-diff(1) and git-log(1), but not for git-format-patch(1) or diff plumbing commands.

--ignore-submodules[=<when>]

: Ignore changes to submodules in the diff generation. <when> can be either "none", "untracked", "dirty" or "all", which is the default. Using "none" will consider the submodule modified when it either contains untracked or modified files or its HEAD differs from the commit recorded in the superproject and can be used to override any settings of the ignore option in git-config(1) or gitmodules(5). When "untracked" is used submodules are not considered dirty when they only contain untracked content (but they are still scanned for modified content). Using "dirty" ignores all changes to the work tree of submodules, only changes to the commits stored in the superproject are shown (this was the behavior until 1.7.0). Using "all" hides all changes to submodules.

--src-prefix=<prefix>

: Show the given source prefix instead of "a/".

--dst-prefix=<prefix>

: Show the given destination prefix instead of "b/".

--no-prefix

: Do not show any source or destination prefix.

--line-prefix=<prefix>

: Prepend an additional prefix to every line of output.

--ita-invisible-in-index

: By default entries added by "git add -N" appear as an existing empty file in "git diff" and a new file in "git diff --cached". This option makes the entry appear as a new file in "git diff" and non-existent in "git diff --cached". This option could be reverted with --ita-visible-in-index. Both options are experimental and could be removed in future.

For more detailed explanation on these common options, see also gitdiffcore(7).

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.

4. All the file1 files in the output refer to files before the commit, and all the file2 files refer to files after the commit. It is incorrect to apply each change to each file sequentially. For example, this patch will swap a and b:

diff --git a/a b/b
rename from a
rename to b
diff --git a/b b/a
rename from b
rename to a

COMBINED DIFF FORMAT

Any diff-generating command can take the -c or --cc option to produce a combined diff when showing a merge. This is the default format when showing merges with git-diff(1) or git-show(1). Note also that you can give 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.

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 Xcqs line is different from it.

A - character in the column N means that the line appears in fileN but it does not appear in the result. A + character in the column N means that the line appears in the result, and fileN does not have that line (in other words, the line was added, from the point of view of that parent).

In the above example output, the function signature was changed from both files (hence two - removals from both file1 and file2, plus ++ to mean one line that was added does not appear in either file1 or file2). Also eight other lines are the same from file1 but do not appear in file2 (hence prefixed with +).

When shown by git diff-tree -c, it compares the parents of a merge commit with the merge result (i.e. file1..fileN are the parents). When shown by git diff-files -c, it compares the two unresolved merge parents with the working tree file (i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka "their version").

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 lq--rq 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.

git log --branches --not --remotes=origin

: Shows all commits that are in any of local branches but not in any of remote-tracking branches for origin (what you have that origin doesncqt).

git log master --not --remotes=*/master

: Shows all commits that are in local master but not in any remote repository master branches.

git log -p -m --first-parent

: Shows the history including change diffs, but only from the lqmain branchrq perspective, skipping commits that come from merged branches, and showing full diffs of changes introduced by the merges. This makes sense only when following a strict policy of merging all topic branches when staying on a single integration branch.

git log -L '/int main/',/^}/:main.c

: Shows how the function main() in the file main.c evolved over time.

git log -3

: Limits the number of commits to show to 3.

DISCUSSION

Git is to some extent character encoding agnostic.

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

: * Path names are encoded in UTF-8 normalization form C. This applies to tree objects, the index file, ref names, as well as path names in command line arguments, environment variables and config files (.git/config (see git-config(1)), gitignore(5), gitattributes(5) and gitmodules(5)).
Note that Git at the core level treats path names simply as sequences of non-NUL bytes, there are no path name encoding conversions (except on Mac and Windows). Therefore, using non-ASCII path names will mostly work even on platforms and file systems that use legacy extended ASCII encodings. However, repositories created on such systems will not work properly on UTF-8-based systems (e.g. Linux, Mac, Windows) and vice versa. Additionally, many Git-based tools simply assume path names to be UTF-8 and will fail to display other encodings correctly.

: * Commit log messages are typically encoded in UTF-8, but other extended ASCII encodings are also supported. This includes ISO-8859-x, CP125x and many others, but not UTF-16/32, EBCDIC and CJK multi-byte encodings (GBK, Shift-JIS, Big5, EUC-x, CP9xx etc.).

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:

[i18n]
        commitencoding = ISO-8859-1

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:

[i18n]
        logoutputencoding = ISO-8859-1

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.

CONFIGURATION

See git-config(1) for core variables and git-diff(1) for settings related to diff generation.

format.pretty

: Default for the --format option. (See Pretty Formats above.) Defaults to medium.

i18n.logOutputEncoding

: Encoding to use when displaying logs. (See Discussion above.) Defaults to the value of i18n.commitEncoding if set, and UTF-8 otherwise.

log.date

: Default format for human-readable dates. (Compare the --date option.) Defaults to "default", which means to write dates like Sat May 8 19:35:34 2010 -0500.

log.follow

: If true, git log will act as if the --follow option was used when a single <path> is given. This has the same limitations as --follow, i.e. it cannot be used to follow multiple files and does not work well on non-linear history.

log.showRoot

: If false, git log and related commands will not treat the initial commit as a big creation event. Any root commits in git log -p output would be shown without a diff attached. The default is true.

log.showSignature

: If true, git log and related commands will act as if the --show-signature option was passed to them.

mailmap.*

: See git-shortlog(1).

notes.displayRef

Which refs, in addition to the default set by core.notesRef or GIT_NOTES_REF, to read notes from when showing commit messages with the log family of commands. See git-notes(1).

May be an unabbreviated ref name or a glob and may be specified multiple times. A warning will be issued for refs that do not exist, but a glob that does not match any refs is silently ignored.

This setting can be disabled by the --no-notes option, overridden by the GIT_NOTES_DISPLAY_REF environment variable, and overridden by the --notes=<ref> option.

GIT

Part of the git(1) suite

PRETTY FORMATS

COMMON DIFF OPTIONS

GENERATING PATCHES WITH -P

COMBINED DIFF FORMAT