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<h3 class="section">1.6 Output (Object) File</h3>

<p><a name="index-object-file-34"></a><a name="index-output-file-35"></a><a name="index-a_002eout-36"></a><a name="index-g_t_002eo-37"></a>Every time you run <samp><span class="command">as</span></samp> it produces an output file, which is
your assembly language program translated into numbers.  This file
is the object file.  Its default name is
<code>a.out</code>. 
You can give it another name by using the <samp><span class="option">-o</span></samp> option.  Conventionally,
object file names end with <samp><span class="file">.o</span></samp>.  The default name is used for historical
reasons: older assemblers were capable of assembling self-contained programs
directly into a runnable program.  (For some formats, this isn't currently
possible, but it can be done for the <code>a.out</code> format.)

   <p><a name="index-linker-38"></a><a name="index-ld-39"></a>The object file is meant for input to the linker <code>ld</code>.  It contains
assembled program code, information to help <code>ld</code> integrate
the assembled program into a runnable file, and (optionally) symbolic
information for the debugger.

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