<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>vscnprintf</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="The Linux Kernel API" /><link rel="up" href="ch02.html#id2621104" title="String Conversions" /><link rel="prev" href="re47.html" title="vsnprintf" /><link rel="next" href="re49.html" title="snprintf" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>vscnprintf</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re47.html">Prev</a> </td><th width="60%" align="center">String Conversions</th><td width="20%" align="right"> <a accesskey="n" href="re49.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="vscnprintf"><a id="API-vscnprintf"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>vscnprintf — Format a string and place it in a buffer </p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">int <b class="fsfunc">vscnprintf </b>(</code></td><td>char * <var class="pdparam">buf</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">size</var>, </td></tr><tr><td> </td><td>const char * <var class="pdparam">fmt</var>, </td></tr><tr><td> </td><td>va_list <var class="pdparam">args</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2622729"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>buf</code></em></span></dt><dd><p> The buffer to place the result into </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p> The size of the buffer, including the trailing null space </p></dd><dt><span class="term"><em class="parameter"><code>fmt</code></em></span></dt><dd><p> The format string to use </p></dd><dt><span class="term"><em class="parameter"><code>args</code></em></span></dt><dd><p> Arguments for the format string </p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2622806"></a><h2>Description</h2><p> The return value is the number of characters which have been written into the <em class="parameter"><code>buf</code></em> not including the trailing '\0'. If <em class="parameter"><code>size</code></em> is <= 0 the function returns 0. </p><p> Call this function if you are already dealing with a va_list. You probably want <code class="function">scnprintf</code> instead. </p><p> See the <code class="function">vsnprintf</code> documentation for format string extensions over C99. </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re47.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch02.html#id2621104">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re49.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>vsnprintf</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>snprintf</span></td></tr></table></div></body></html>