<?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>vsnprintf</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="re46.html" title="strict_strtoll" /><link rel="next" href="re48.html" title="vscnprintf" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>vsnprintf</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re46.html">Prev</a> </td><th width="60%" align="center">String Conversions</th><td width="20%" align="right"> <a accesskey="n" href="re48.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="vsnprintf"><a id="API-vsnprintf"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>vsnprintf —
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">vsnprintf </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="id2622490"></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="id2622567"></a><h2>Description</h2><p>
This function follows C99 vsnprintf, but has some extensions:
<code class="constant">pS</code> output the name of a text symbol with offset
<code class="constant">ps</code> output the name of a text symbol without offset
<code class="constant">pF</code> output the name of a function pointer with its offset
<code class="constant">pf</code> output the name of a function pointer without its offset
<code class="constant">pR</code> output the address range in a struct resource
<code class="constant">n</code> is ignored
</p><p>
The return value is the number of characters which would
be generated for the given input, excluding the trailing
'\0', as per ISO C99. If you want to have the exact
number of characters written into <em class="parameter"><code>buf</code></em> as return value
(not including the trailing '\0'), use <code class="function">vscnprintf</code>. If the
return is greater than or equal to <em class="parameter"><code>size</code></em>, the resulting
string is truncated.
</p><p>
Call this function if you are already dealing with a va_list.
You probably want <code class="function">snprintf</code> instead.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re46.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="re48.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>strict_strtoll</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>vscnprintf</span></td></tr></table></div></body></html>
