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</style>
<title>git-blame(1)</title>
</head>
<body>
<div id="header">
<h1>
git-blame(1) Manual Page
</h1>
<h2>NAME</h2>
<div class="sectionbody">
<p>git-blame -
Show what revision and author last modified each line of a file
</p>
</div>
</div>
<h2>SYNOPSIS</h2>
<div class="sectionbody">
<div class="verseblock">
<div class="content"><em>git blame</em> [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-p] [-w] [--incremental] [-L n,m]
[-S &lt;revs-file&gt;] [-M] [-C] [-C] [--since=&lt;date&gt;]
[&lt;rev&gt; | --contents &lt;file&gt; | --reverse &lt;rev&gt;] [--] &lt;file&gt;</div></div>
</div>
<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
<div class="para"><p>Annotates each line in the given file with information from the revision which
last modified the line. Optionally, start annotating from the given revision.</p></div>
<div class="para"><p>The command can also limit the range of lines annotated.</p></div>
<div class="para"><p>The report does not tell you anything about lines which have been deleted or
replaced; you need to use a tool such as <em>git-diff</em> or the "pickaxe"
interface briefly mentioned in the following paragraph.</p></div>
<div class="para"><p>Apart from supporting file annotation, git also supports searching the
development history for when a code snippet occurred in a change. This makes it
possible to track when a code snippet was added to a file, moved or copied
between files, and eventually deleted or replaced. It works by searching for
a text string in the diff. A small example:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>$ git log --pretty=oneline -S'blame_usage'
5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S &lt;ancestry-file&gt;
ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output</tt></pre>
</div></div>
</div>
<h2 id="_options">OPTIONS</h2>
<div class="sectionbody">
<div class="vlist"><dl>
<dt>
-b
</dt>
<dd>
<p>
Show blank SHA-1 for boundary commits. This can also
be controlled via the <tt>blame.blankboundary</tt> config option.
</p>
</dd>
<dt>
--root
</dt>
<dd>
<p>
Do not treat root commits as boundaries. This can also be
controlled via the <tt>blame.showroot</tt> config option.
</p>
</dd>
<dt>
--show-stats
</dt>
<dd>
<p>
Include additional statistics at the end of blame output.
</p>
</dd>
<dt>
-L &lt;start&gt;,&lt;end&gt;
</dt>
<dd>
<p>
Annotate only the given line range. &lt;start&gt; and &lt;end&gt; can take
one of these forms:
</p>
<div class="ilist"><ul>
<li>
<p>
number
</p>
<div class="para"><p>If &lt;start&gt; or &lt;end&gt; is a number, it specifies an
absolute line number (lines count from 1).</p></div>
</li>
<li>
<p>
/regex/
</p>
<div class="para"><p>This form will use the first line matching the given
POSIX regex. If &lt;end&gt; is a regex, it will search
starting at the line given by &lt;start&gt;.</p></div>
</li>
<li>
<p>
+offset or -offset
</p>
<div class="para"><p>This is only valid for &lt;end&gt; and will specify a number
of lines before or after the line given by &lt;start&gt;.</p></div>
</li>
</ul></div>
</dd>
<dt>
-l
</dt>
<dd>
<p>
Show long rev (Default: off).
</p>
</dd>
<dt>
-t
</dt>
<dd>
<p>
Show raw timestamp (Default: off).
</p>
</dd>
<dt>
-S &lt;revs-file&gt;
</dt>
<dd>
<p>
Use revisions from revs-file instead of calling <a href="git-rev-list.html">git-rev-list(1)</a>.
</p>
</dd>
<dt>
--reverse
</dt>
<dd>
<p>
Walk history forward instead of backward. Instead of showing
the revision in which a line appeared, this shows the last
revision in which a line has existed. This requires a range of
revision like START..END where the path to blame exists in
START.
</p>
</dd>
<dt>
-p
</dt>
<dt>
--porcelain
</dt>
<dd>
<p>
Show in a format designed for machine consumption.
</p>
</dd>
<dt>
--incremental
</dt>
<dd>
<p>
Show the result incrementally in a format designed for
machine consumption.
</p>
</dd>
<dt>
--encoding=&lt;encoding&gt;
</dt>
<dd>
<p>
Specifies the encoding used to output author names
and commit summaries. Setting it to <tt>none</tt> makes blame
output unconverted data. For more information see the
discussion about encoding in the <a href="git-log.html">git-log(1)</a>
manual page.
</p>
</dd>
<dt>
--contents &lt;file&gt;
</dt>
<dd>
<p>
When &lt;rev&gt; is not specified, the command annotates the
changes starting backwards from the working tree copy.
This flag makes the command pretend as if the working
tree copy has the contents of the named file (specify
<tt>-</tt> to make the command read from the standard input).
</p>
</dd>
<dt>
--date &lt;format&gt;
</dt>
<dd>
<p>
The value is one of the following alternatives:
{relative,local,default,iso,rfc,short}. If --date is not
provided, the value of the blame.date config variable is
used. If the blame.date config variable is also not set, the
iso format is used. For more information, See the discussion
of the --date option at <a href="git-log.html">git-log(1)</a>.
</p>
</dd>
<dt>
-M|&lt;num&gt;|
</dt>
<dd>
<p>
Detect moving lines in the file as well. When a commit
moves a block of lines in a file (e.g. the original file
has A and then B, and the commit changes it to B and
then A), the traditional <em>blame</em> algorithm typically blames
the lines that were moved up (i.e. B) to the parent and
assigns blame to the lines that were moved down (i.e. A)
to the child commit. With this option, both groups of lines
are blamed on the parent.
</p>
<div class="para"><p>&lt;num&gt; is optional but it is the lower bound on the number of
alphanumeric characters that git must detect as moving
within a file for it to associate those lines with the parent
commit.</p></div>
</dd>
<dt>
-C|&lt;num&gt;|
</dt>
<dd>
<p>
In addition to <tt>-M</tt>, detect lines copied from other
files that were modified in the same commit. This is
useful when you reorganize your program and move code
around across files. When this option is given twice,
the command additionally looks for copies from all other
files in the parent for the commit that creates the file.
</p>
<div class="para"><p>&lt;num&gt; is optional but it is the lower bound on the number of
alphanumeric characters that git must detect as moving
between files for it to associate those lines with the parent
commit.</p></div>
</dd>
<dt>
-h
</dt>
<dt>
--help
</dt>
<dd>
<p>
Show help message.
</p>
</dd>
<dt>
-c
</dt>
<dd>
<p>
Use the same output mode as <a href="git-annotate.html">git-annotate(1)</a> (Default: off).
</p>
</dd>
<dt>
--score-debug
</dt>
<dd>
<p>
Include debugging information related to the movement of
lines between files (see <tt>-C</tt>) and lines moved within a
file (see <tt>-M</tt>). The first number listed is the score.
This is the number of alphanumeric characters detected
as having been moved between or within files. This must be above
a certain threshold for <em>git-blame</em> to consider those lines
of code to have been moved.
</p>
</dd>
<dt>
-f
</dt>
<dt>
--show-name
</dt>
<dd>
<p>
Show the filename in the original commit. By default
the filename is shown if there is any line that came from a
file with a different name, due to rename detection.
</p>
</dd>
<dt>
-n
</dt>
<dt>
--show-number
</dt>
<dd>
<p>
Show the line number in the original commit (Default: off).
</p>
</dd>
<dt>
-s
</dt>
<dd>
<p>
Suppress the author name and timestamp from the output.
</p>
</dd>
<dt>
-w
</dt>
<dd>
<p>
Ignore whitespace when comparing the parent's version and
the child's to find where the lines came from.
</p>
</dd>
</dl></div>
</div>
<h2 id="_the_porcelain_format">THE PORCELAIN FORMAT</h2>
<div class="sectionbody">
<div class="para"><p>In this format, each line is output after a header; the
header at the minimum has the first line which has:</p></div>
<div class="ilist"><ul>
<li>
<p>
40-byte SHA-1 of the commit the line is attributed to;
</p>
</li>
<li>
<p>
the line number of the line in the original file;
</p>
</li>
<li>
<p>
the line number of the line in the final file;
</p>
</li>
<li>
<p>
on a line that starts a group of lines from a different
commit than the previous one, the number of lines in this
group. On subsequent lines this field is absent.
</p>
</li>
</ul></div>
<div class="para"><p>This header line is followed by the following information
at least once for each commit:</p></div>
<div class="ilist"><ul>
<li>
<p>
the author name ("author"), email ("author-mail"), time
("author-time"), and timezone ("author-tz"); similarly
for committer.
</p>
</li>
<li>
<p>
the filename in the commit that the line is attributed to.
</p>
</li>
<li>
<p>
the first line of the commit log message ("summary").
</p>
</li>
</ul></div>
<div class="para"><p>The contents of the actual line is output after the above
header, prefixed by a TAB. This is to allow adding more
header elements later.</p></div>
</div>
<h2 id="_specifying_ranges">SPECIFYING RANGES</h2>
<div class="sectionbody">
<div class="para"><p>Unlike <em>git-blame</em> and <em>git-annotate</em> in older versions of git, the extent
of the annotation can be limited to both line ranges and revision
ranges. When you are interested in finding the origin for
lines 40-60 for file <tt>foo</tt>, you can use the <tt>-L</tt> option like so
(they mean the same thing &#8212; both ask for 21 lines starting at
line 40):</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>git blame -L 40,60 foo
git blame -L 40,+21 foo</tt></pre>
</div></div>
<div class="para"><p>Also you can use a regular expression to specify the line range:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>git blame -L '/^sub hello {/,/^}$/' foo</tt></pre>
</div></div>
<div class="para"><p>which limits the annotation to the body of the <tt>hello</tt> subroutine.</p></div>
<div class="para"><p>When you are not interested in changes older than version
v2.6.18, or changes older than 3 weeks, you can use revision
range specifiers similar to <em>git-rev-list</em>:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>git blame v2.6.18.. -- foo
git blame --since=3.weeks -- foo</tt></pre>
</div></div>
<div class="para"><p>When revision range specifiers are used to limit the annotation,
lines that have not changed since the range boundary (either the
commit v2.6.18 or the most recent commit that is more than 3
weeks old in the above example) are blamed for that range
boundary commit.</p></div>
<div class="para"><p>A particularly useful way is to see if an added file has lines
created by copy-and-paste from existing files. Sometimes this
indicates that the developer was being sloppy and did not
refactor the code properly. You can first find the commit that
introduced the file with:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>git log --diff-filter=A --pretty=short -- foo</tt></pre>
</div></div>
<div class="para"><p>and then annotate the change between the commit and its
parents, using <tt>commit&#94;!</tt> notation:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>git blame -C -C -f $commit^! -- foo</tt></pre>
</div></div>
</div>
<h2 id="_incremental_output">INCREMENTAL OUTPUT</h2>
<div class="sectionbody">
<div class="para"><p>When called with <tt>--incremental</tt> option, the command outputs the
result as it is built. The output generally will talk about
lines touched by more recent commits first (i.e. the lines will
be annotated out of order) and is meant to be used by
interactive viewers.</p></div>
<div class="para"><p>The output format is similar to the Porcelain format, but it
does not contain the actual lines from the file that is being
annotated.</p></div>
<div class="olist"><ol>
<li>
<p>
Each blame entry always starts with a line of:
</p>
<div class="literalblock">
<div class="content">
<pre><tt>&lt;40-byte hex sha1&gt; &lt;sourceline&gt; &lt;resultline&gt; &lt;num_lines&gt;</tt></pre>
</div></div>
<div class="para"><p>Line numbers count from 1.</p></div>
</li>
<li>
<p>
The first time that a commit shows up in the stream, it has various
other information about it printed out with a one-word tag at the
beginning of each line describing the extra commit information (author,
email, committer, dates, summary, etc.).
</p>
</li>
<li>
<p>
Unlike the Porcelain format, the filename information is always
given and terminates the entry:
</p>
<div class="literalblock">
<div class="content">
<pre><tt>"filename" &lt;whitespace-quoted-filename-goes-here&gt;</tt></pre>
</div></div>
<div class="para"><p>and thus it is really quite easy to parse for some line- and word-oriented
parser (which should be quite natural for most scripting languages).</p></div>
<div class="admonitionblock">
<table><tr>
<td class="icon">
<div class="title">Note</div>
</td>
<td class="content">For people who do parsing: to make it more robust, just ignore any
lines between the first and last one ("&lt;sha1&gt;" and "filename" lines)
where you do not recognize the tag words (or care about that particular
one) at the beginning of the "extended information" lines. That way, if
there is ever added information (like the commit encoding or extended
commit commentary), a blame viewer will not care.</td>
</tr></table>
</div>
</li>
</ol></div>
</div>
<h2 id="_mapping_authors">MAPPING AUTHORS</h2>
<div class="sectionbody">
<div class="para"><p>If the file <tt>.mailmap</tt> exists at the toplevel of the repository, or at
the location pointed to by the mailmap.file configuration option, it
is used to map author and committer names and email addresses to
canonical real names and email addresses.</p></div>
<div class="para"><p>In the simple form, each line in the file consists of the canonical
real name of an author, whitespace, and an email address used in the
commit (enclosed by <em>&lt;</em> and <em>&gt;</em>) to map to the name. For example:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>Proper Name &lt;commit@email.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>The more complex forms are:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>&lt;proper@email.xx&gt; &lt;commit@email.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>which allows mailmap to replace only the email part of a commit, and:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>Proper Name &lt;proper@email.xx&gt; &lt;commit@email.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>which allows mailmap to replace both the name and the email of a
commit matching the specified commit email address, and:</p></div>
<div class="literalblock">
<div class="content">
<pre><tt>Proper Name &lt;proper@email.xx&gt; Commit Name &lt;commit@email.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>which allows mailmap to replace both the name and the email of a
commit matching both the specified commit name and email address.</p></div>
<div class="para"><p>Example 1: Your history contains commits by two authors, Jane
and Joe, whose names appear in the repository under several forms:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>Joe Developer &lt;joe@example.com&gt;
Joe R. Developer &lt;joe@example.com&gt;
Jane Doe &lt;jane@example.com&gt;
Jane Doe &lt;jane@laptop.(none)&gt;
Jane D. &lt;jane@desktop.(none)&gt;</tt></pre>
</div></div>
<div class="para"><p>Now suppose that Joe wants his middle name initial used, and Jane
prefers her family name fully spelled out. A proper <tt>.mailmap</tt> file
would look like:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>Jane Doe &lt;jane@desktop.(none)&gt;
Joe R. Developer &lt;joe@example.com&gt;</tt></pre>
</div></div>
<div class="para"><p>Note how there is no need for an entry for &lt;jane@laptop.(none)&gt;, because the
real name of that author is already correct.</p></div>
<div class="para"><p>Example 2: Your repository contains commits from the following
authors:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>nick1 &lt;bugs@company.xx&gt;
nick2 &lt;bugs@company.xx&gt;
nick2 &lt;nick2@company.xx&gt;
santa &lt;me@company.xx&gt;
claus &lt;me@company.xx&gt;
CTO &lt;cto@coompany.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>Then you might want a <tt>.mailmap</tt> file that looks like:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt>&lt;cto@company.xx&gt; &lt;cto@coompany.xx&gt;
Some Dude &lt;some@dude.xx&gt; nick1 &lt;bugs@company.xx&gt;
Other Author &lt;other@author.xx&gt; nick2 &lt;bugs@company.xx&gt;
Other Author &lt;other@author.xx&gt; &lt;nick2@company.xx&gt;
Santa Claus &lt;santa.claus@northpole.xx&gt; &lt;me@company.xx&gt;</tt></pre>
</div></div>
<div class="para"><p>Use hash <em>#</em> for comments that are either on their own line, or after
the email address.</p></div>
</div>
<h2 id="_see_also">SEE ALSO</h2>
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<div class="para"><p><a href="git-annotate.html">git-annotate(1)</a></p></div>
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<h2 id="_author">AUTHOR</h2>
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<div class="para"><p>Written by Junio C Hamano &lt;gitster@pobox.com&gt;</p></div>
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<div class="para"><p>Part of the <a href="git.html">git(1)</a> suite</p></div>
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Last updated 2009-07-01 02:30:43 UTC
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