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| <h4 class="subsection">A.2.2 How Variadic Functions are Defined and Used</h4> |
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| <p>Defining and using a variadic function involves three steps: |
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| <ul> |
| <li><em>Define</em> the function as variadic, using an ellipsis |
| (‘<samp><span class="samp">...</span></samp>’) in the argument list, and using special macros to |
| access the variable arguments. See <a href="Receiving-Arguments.html#Receiving-Arguments">Receiving Arguments</a>. |
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| <li><em>Declare</em> the function as variadic, using a prototype with an |
| ellipsis (‘<samp><span class="samp">...</span></samp>’), 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>. |
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| <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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