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 </style>
 <title>builtin API</title>
 </head>
 <body>
 <div id="header">
 <h1>builtin API</h1>
 </div>
 <h2>Adding a new built-in</h2>
 <div class="sectionbody">
 <p>There are 4 things to do to add a bulit-in command implementation to
 git:</p>
 <ol>
 <li>
 <p>
 Define the implementation of the built-in command <tt>foo</tt> with
  signature:
 </p>
 <div class="literalblock">
 <div class="content">
 <pre><tt>int cmd_foo(int argc, const char **argv, const char *prefix);</tt></pre>
 </div></div>
 </li>
 <li>
 <p>
 Add the external declaration for the function to <tt>builtin.h</tt>.
 </p>
 </li>
 <li>
 <p>
 Add the command to <tt>commands[]</tt> table in <tt>handle_internal_command()</tt>,
  defined in <tt>git.c</tt>. The entry should look like:
 </p>
 <div class="literalblock">
 <div class="content">
 <pre><tt>{ "foo", cmd_foo, &lt;options&gt; },</tt></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><tt>where options is the bitwise-or of:</tt></pre>
 </div></div>
 <dl>
 <dt>
 <tt>RUN_SETUP</tt>
 </dt>
 <dd>
 <p>
  Make sure there is a git directory to work on, and if there is a
  work tree, chdir to the top of it if the command was invoked
  in a subdirectory. If there is no work tree, no chdir() is
  done.
 </p>
 </dd>
 <dt>
 <tt>USE_PAGER</tt>
 </dt>
 <dd>
 <p>
  If the standard output is connected to a tty, spawn a pager and
  feed our output to it.
 </p>
 </dd>
 </dl>
 </li>
 <li>
 <p>
 Add <tt>builtin-foo.o</tt> to <tt>BUILTIN_OBJS</tt> in <tt>Makefile</tt>.
 </p>
 </li>
 </ol>
 <p>Additionally, if <tt>foo</tt> is a new command, there are 3 more things to do:</p>
 <ol>
 <li>
 <p>
 Add tests to <tt>t/</tt> directory.
 </p>
 </li>
 <li>
 <p>
 Write documentation in <tt>Documentation/git-foo.txt</tt>.
 </p>
 </li>
 <li>
 <p>
 Add an entry for <tt>git-foo</tt> to the list at the end of
  <tt>Documentation/cmd-list.perl</tt>.
 </p>
 </li>
 </ol>
 </div>
 <h2>How a built-in is called</h2>
 <div class="sectionbody">
 <p>The implementation <tt>cmd_foo()</tt> takes three parameters, <tt>argc</tt>, <tt>argv,
 and `prefix</tt>. The first two are similar to what <tt>main()</tt> of a
 standalone command would be called with.</p>
 <p>When <tt>RUN_SETUP</tt> is specified in the <tt>commands[]</tt> table, and when you
 were started from a subdirectory of the work tree, <tt>cmd_foo()</tt> is called
 after chdir(2) to the top of the work tree, and <tt>prefix</tt> gets the path
 to the subdirectory the command started from. This allows you to
 convert a user-supplied pathname (typically relative to that directory)
 to a pathname relative to the top of the work tree.</p>
 <p>The return value from <tt>cmd_foo()</tt> becomes the exit status of the
 command.</p>
 </div>
 <div id="footer">
 <div id="footer-text">
 Last updated 07-Jan-2008 07:51:18 UTC
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	</style>
	<title>builtin API</title>
	</head>
	<body>
	<div id="header">
	<h1>builtin API</h1>
	</div>
	<h2>Adding a new built-in</h2>
	<div class="sectionbody">
	<p>There are 4 things to do to add a bulit-in command implementation to
	git:</p>
	<ol>
	<li>
	<p>
	Define the implementation of the built-in command <tt>foo</tt> with
	signature:
	</p>
	<div class="literalblock">
	<div class="content">
	<pre><tt>int cmd_foo(int argc, const char *argv, const char prefix);</tt></pre>
	</div></div>
	</li>
	<li>
	<p>
	Add the external declaration for the function to <tt>builtin.h</tt>.
	</p>
	</li>
	<li>
	<p>
	Add the command to <tt>commands[]</tt> table in <tt>handle_internal_command()</tt>,
	defined in <tt>git.c</tt>. The entry should look like:
	</p>
	<div class="literalblock">
	<div class="content">
	<pre><tt>{ "foo", cmd_foo, <options> },</tt></pre>
	</div></div>
	<div class="literalblock">
	<div class="content">
	<pre><tt>where options is the bitwise-or of:</tt></pre>
	</div></div>
	<dl>
	<dt>
	<tt>RUN_SETUP</tt>
	</dt>
	<dd>
	<p>
	Make sure there is a git directory to work on, and if there is a
	work tree, chdir to the top of it if the command was invoked
	in a subdirectory. If there is no work tree, no chdir() is
	done.
	</p>
	</dd>
	<dt>
	<tt>USE_PAGER</tt>
	</dt>
	<dd>
	<p>
	If the standard output is connected to a tty, spawn a pager and
	feed our output to it.
	</p>
	</dd>
	</dl>
	</li>
	<li>
	<p>
	Add <tt>builtin-foo.o</tt> to <tt>BUILTIN_OBJS</tt> in <tt>Makefile</tt>.
	</p>
	</li>
	</ol>
	<p>Additionally, if <tt>foo</tt> is a new command, there are 3 more things to do:</p>
	<ol>
	<li>
	<p>
	Add tests to <tt>t/</tt> directory.
	</p>
	</li>
	<li>
	<p>
	Write documentation in <tt>Documentation/git-foo.txt</tt>.
	</p>
	</li>
	<li>
	<p>
	Add an entry for <tt>git-foo</tt> to the list at the end of
	<tt>Documentation/cmd-list.perl</tt>.
	</p>
	</li>
	</ol>
	</div>
	<h2>How a built-in is called</h2>
	<div class="sectionbody">
	<p>The implementation <tt>cmd_foo()</tt> takes three parameters, <tt>argc</tt>, <tt>argv,
	and `prefix</tt>. The first two are similar to what <tt>main()</tt> of a
	standalone command would be called with.</p>
	<p>When <tt>RUN_SETUP</tt> is specified in the <tt>commands[]</tt> table, and when you
	were started from a subdirectory of the work tree, <tt>cmd_foo()</tt> is called
	after chdir(2) to the top of the work tree, and <tt>prefix</tt> gets the path
	to the subdirectory the command started from. This allows you to
	convert a user-supplied pathname (typically relative to that directory)
	to a pathname relative to the top of the work tree.</p>
	<p>The return value from <tt>cmd_foo()</tt> becomes the exit status of the
	command.</p>
	</div>
	<div id="footer">
	<div id="footer-text">
	Last updated 07-Jan-2008 07:51:18 UTC
	</div>
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	</body>
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