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<h4 class="subsection">A.2.2 How Variadic Functions are Defined and Used</h4>

<p>Defining and using a variadic function involves three steps:

     <ul>
<li><em>Define</em> the function as variadic, using an ellipsis
(&lsquo;<samp><span class="samp">...</span></samp>&rsquo;) in the argument list, and using special macros to
access the variable arguments.  See <a href="Receiving-Arguments.html#Receiving-Arguments">Receiving Arguments</a>.

     <li><em>Declare</em> the function as variadic, using a prototype with an
ellipsis (&lsquo;<samp><span class="samp">...</span></samp>&rsquo;), in all the files which call it. 
See <a href="Variadic-Prototypes.html#Variadic-Prototypes">Variadic Prototypes</a>.

     <li><em>Call</em> the function by writing the fixed arguments followed by the
additional variable arguments.  See <a href="Calling-Variadics.html#Calling-Variadics">Calling Variadics</a>. 
</ul>

<ul class="menu">
<li><a accesskey="1" href="Variadic-Prototypes.html#Variadic-Prototypes">Variadic Prototypes</a>:   How to make a prototype for a function
			  with variable arguments. 
<li><a accesskey="2" href="Receiving-Arguments.html#Receiving-Arguments">Receiving Arguments</a>:   Steps you must follow to access the
			  optional argument values. 
<li><a accesskey="3" href="How-Many-Arguments.html#How-Many-Arguments">How Many Arguments</a>:    How to decide whether there are more arguments. 
<li><a accesskey="4" href="Calling-Variadics.html#Calling-Variadics">Calling Variadics</a>:     Things you need to know about calling
			  variable arguments functions. 
<li><a accesskey="5" href="Argument-Macros.html#Argument-Macros">Argument Macros</a>:       Detailed specification of the macros
        		  for accessing variable arguments. 
<li><a accesskey="6" href="Old-Varargs.html#Old-Varargs">Old Varargs</a>: 		 The pre-ISO way of defining variadic functions. 
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