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<a name="File-Commands"></a>
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<p>
Next: <a href="Format-Commands.html#Format-Commands" accesskey="n" rel="next">Format Commands</a>, Previous: <a href="Entry-Point.html#Entry-Point" accesskey="p" rel="prev">Entry Point</a>, Up: <a href="Simple-Commands.html#Simple-Commands" accesskey="u" rel="up">Simple Commands</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LD-Index.html#LD-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Commands-Dealing-with-Files"></a>
<h4 class="subsection">3.4.2 Commands Dealing with Files</h4>
<a name="index-linker-script-file-commands"></a>
<p>Several linker script commands deal with files.
</p>
<dl compact="compact">
<dt><code>INCLUDE <var>filename</var></code></dt>
<dd><a name="index-INCLUDE-filename"></a>
<a name="index-including-a-linker-script"></a>
<p>Include the linker script <var>filename</var> at this point.  The file will
be searched for in the current directory, and in any directory specified
with the <samp>-L</samp> option.  You can nest calls to <code>INCLUDE</code> up to
10 levels deep.
</p>
<p>You can place <code>INCLUDE</code> directives at the top level, in <code>MEMORY</code> or
<code>SECTIONS</code> commands, or in output section descriptions.
</p>
</dd>
<dt><code>INPUT(<var>file</var>, <var>file</var>, &hellip;)</code></dt>
<dt><code>INPUT(<var>file</var> <var>file</var> &hellip;)</code></dt>
<dd><a name="index-INPUT_0028files_0029"></a>
<a name="index-input-files-in-linker-scripts"></a>
<a name="index-input-object-files-in-linker-scripts"></a>
<a name="index-linker-script-input-object-files"></a>
<p>The <code>INPUT</code> command directs the linker to include the named files
in the link, as though they were named on the command line.
</p>
<p>For example, if you always want to include <samp>subr.o</samp> any time you do
a link, but you can&rsquo;t be bothered to put it on every link command line,
then you can put &lsquo;<samp>INPUT (subr.o)</samp>&rsquo; in your linker script.
</p>
<p>In fact, if you like, you can list all of your input files in the linker
script, and then invoke the linker with nothing but a &lsquo;<samp>-T</samp>&rsquo; option.
</p>
<p>In case a <em>sysroot prefix</em> is configured, and the filename starts
with the &lsquo;<samp>/</samp>&rsquo; character, and the script being processed was
located inside the <em>sysroot prefix</em>, the filename will be looked
for in the <em>sysroot prefix</em>.  Otherwise, the linker will try to
open the file in the current directory.  If it is not found, the
linker will search through the archive library search path.
The <em>sysroot prefix</em> can also be forced by specifying <code>=</code>
as the first character in the filename path.  See also the
description of &lsquo;<samp>-L</samp>&rsquo; in <a href="Options.html#Options">Command Line Options</a>.
</p>
<p>If you use &lsquo;<samp>INPUT (-l<var>file</var>)</samp>&rsquo;, <code>ld</code> will transform the
name to <code>lib<var>file</var>.a</code>, as with the command line argument
&lsquo;<samp>-l</samp>&rsquo;.
</p>
<p>When you use the <code>INPUT</code> command in an implicit linker script, the
files will be included in the link at the point at which the linker
script file is included.  This can affect archive searching.
</p>
</dd>
<dt><code>GROUP(<var>file</var>, <var>file</var>, &hellip;)</code></dt>
<dt><code>GROUP(<var>file</var> <var>file</var> &hellip;)</code></dt>
<dd><a name="index-GROUP_0028files_0029"></a>
<a name="index-grouping-input-files"></a>
<p>The <code>GROUP</code> command is like <code>INPUT</code>, except that the named
files should all be archives, and they are searched repeatedly until no
new undefined references are created.  See the description of &lsquo;<samp>-(</samp>&rsquo;
in <a href="Options.html#Options">Command Line Options</a>.
</p>
</dd>
<dt><code>AS_NEEDED(<var>file</var>, <var>file</var>, &hellip;)</code></dt>
<dt><code>AS_NEEDED(<var>file</var> <var>file</var> &hellip;)</code></dt>
<dd><a name="index-AS_005fNEEDED_0028files_0029"></a>
<p>This construct can appear only inside of the <code>INPUT</code> or <code>GROUP</code>
commands, among other filenames.  The files listed will be handled
as if they appear directly in the <code>INPUT</code> or <code>GROUP</code> commands,
with the exception of ELF shared libraries, that will be added only
when they are actually needed.  This construct essentially enables
<samp>--as-needed</samp> option for all the files listed inside of it
and restores previous <samp>--as-needed</samp> resp. <samp>--no-as-needed</samp>
setting afterwards.
</p>
</dd>
<dt><code>OUTPUT(<var>filename</var>)</code></dt>
<dd><a name="index-OUTPUT_0028filename_0029"></a>
<a name="index-output-file-name-in-linker-script"></a>
<p>The <code>OUTPUT</code> command names the output file.  Using
<code>OUTPUT(<var>filename</var>)</code> in the linker script is exactly like using
&lsquo;<samp>-o <var>filename</var></samp>&rsquo; on the command line (see <a href="Options.html#Options">Command
Line Options</a>).  If both are used, the command line option takes
precedence.
</p>
<p>You can use the <code>OUTPUT</code> command to define a default name for the
output file other than the usual default of <samp>a.out</samp>.
</p>
</dd>
<dt><code>SEARCH_DIR(<var>path</var>)</code></dt>
<dd><a name="index-SEARCH_005fDIR_0028path_0029"></a>
<a name="index-library-search-path-in-linker-script"></a>
<a name="index-archive-search-path-in-linker-script"></a>
<a name="index-search-path-in-linker-script"></a>
<p>The <code>SEARCH_DIR</code> command adds <var>path</var> to the list of paths where
<code>ld</code> looks for archive libraries.  Using
<code>SEARCH_DIR(<var>path</var>)</code> is exactly like using &lsquo;<samp>-L <var>path</var></samp>&rsquo;
on the command line (see <a href="Options.html#Options">Command Line Options</a>).  If both
are used, then the linker will search both paths.  Paths specified using
the command line option are searched first.
</p>
</dd>
<dt><code>STARTUP(<var>filename</var>)</code></dt>
<dd><a name="index-STARTUP_0028filename_0029"></a>
<a name="index-first-input-file"></a>
<p>The <code>STARTUP</code> command is just like the <code>INPUT</code> command, except
that <var>filename</var> will become the first input file to be linked, as
though it were specified first on the command line.  This may be useful
when using a system in which the entry point is always the start of the
first file.
</p></dd>
</dl>

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<div class="header">
<p>
Next: <a href="Format-Commands.html#Format-Commands" accesskey="n" rel="next">Format Commands</a>, Previous: <a href="Entry-Point.html#Entry-Point" accesskey="p" rel="prev">Entry Point</a>, Up: <a href="Simple-Commands.html#Simple-Commands" accesskey="u" rel="up">Simple Commands</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LD-Index.html#LD-Index" title="Index" rel="index">Index</a>]</p>
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