<?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>usb_gadget_get_string</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="USB Gadget API for Linux" /><link rel="up" href="ch03s04.html" title="Optional Utilities" /><link rel="prev" href="ch03s04.html" title="Optional Utilities" /><link rel="next" href="re48.html" title="usb_descriptor_fillbuf" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>usb_gadget_get_string</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch03s04.html">Prev</a> </td><th width="60%" align="center">Optional Utilities</th><td width="20%" align="right"> <a accesskey="n" href="re48.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="usb_gadget_get_string"><a id="API-usb-gadget-get-string"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>usb_gadget_get_string —
fill out a string descriptor
</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">usb_gadget_get_string </b>(</code></td><td>struct usb_gadget_strings * <var class="pdparam">table</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">id</var>, </td></tr><tr><td> </td><td>u8 * <var class="pdparam">buf</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2943532"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>table</code></em></span></dt><dd><p>
of c strings encoded using UTF-8
</p></dd><dt><span class="term"><em class="parameter"><code>id</code></em></span></dt><dd><p>
string id, from low byte of wValue in get string descriptor
</p></dd><dt><span class="term"><em class="parameter"><code>buf</code></em></span></dt><dd><p>
at least 256 bytes
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2943592"></a><h2>Description</h2><p>
Finds the UTF-8 string matching the ID, and converts it into a
string descriptor in utf16-le.
Returns length of descriptor (always even) or negative errno
</p><p>
If your driver needs stings in multiple languages, you'll probably
<span class="quote">“<span class="quote">switch (wIndex) { ... }</span>”</span> in your ep0 string descriptor logic,
using this routine after choosing which set of UTF-8 strings to use.
Note that US-ASCII is a strict subset of UTF-8; any string bytes with
the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1
characters (which are also widely used in C strings).
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch03s04.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch03s04.html">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">Optional Utilities </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>usb_descriptor_fillbuf</span></td></tr></table></div></body></html>
