1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>vsprintf</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="libc.html#idp1122555668" title="String Conversions"><link rel="prev" href="API-scnprintf.html" title="scnprintf"><link rel="next" href="API-sprintf.html" title="sprintf"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">vsprintf</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-scnprintf.html">Prev</a>&#160;</td><th width="60%" align="center">String Conversions</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-sprintf.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-vsprintf"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>vsprintf &#8212; 
2     Format a string and place it in a buffer
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">vsprintf </b>(</code></td><td>char * <var class="pdparam">buf</var>, </td></tr><tr><td>&#160;</td><td>const char * <var class="pdparam">fmt</var>, </td></tr><tr><td>&#160;</td><td>va_list <var class="pdparam">args</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1122654948"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>buf</code></em></span></dt><dd><p>
4     The buffer to place the result into
5    </p></dd><dt><span class="term"><em class="parameter"><code>fmt</code></em></span></dt><dd><p>
6     The format string to use
7    </p></dd><dt><span class="term"><em class="parameter"><code>args</code></em></span></dt><dd><p>
8     Arguments for the format string
9    </p></dd></dl></div></div><div class="refsect1"><a name="idp1122658524"></a><h2>Description</h2><p>
10   The function returns the number of characters written
11   into <em class="parameter"><code>buf</code></em>. Use <code class="function">vsnprintf</code> or <code class="function">vscnprintf</code> in order to avoid
12   buffer overflows.
13   </p><p>
14
15   If you're not already dealing with a va_list consider using <code class="function">sprintf</code>.
16   </p><p>
17
18   See the <code class="function">vsnprintf</code> documentation for format string extensions over C99.
19</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-scnprintf.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="libc.html#idp1122555668">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-sprintf.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">scnprintf</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">sprintf</span></td></tr></table></div></body></html>
20