1<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>dvb_ringbuffer_pkt_read_user</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Device Drivers"><link rel="up" href="ch06s02.html" title="Digital TV (DVB) devices"><link rel="prev" href="API-dvb-ringbuffer-pkt-write.html" title="dvb_ringbuffer_pkt_write"><link rel="next" href="API-dvb-ringbuffer-pkt-read.html" title="dvb_ringbuffer_pkt_read"></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">dvb_ringbuffer_pkt_read_user</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-dvb-ringbuffer-pkt-write.html">Prev</a> </td><th width="60%" align="center">Digital TV (DVB) devices</th><td width="20%" align="right"> <a accesskey="n" href="API-dvb-ringbuffer-pkt-read.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-dvb-ringbuffer-pkt-read-user"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>dvb_ringbuffer_pkt_read_user — 2 Read from a packet in the ringbuffer. 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">ssize_t <b class="fsfunc">dvb_ringbuffer_pkt_read_user </b>(</code></td><td>struct dvb_ringbuffer * <var class="pdparam">rbuf</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">idx</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">offset</var>, </td></tr><tr><td> </td><td>u8 __user * <var class="pdparam">buf</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">len</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="id-1.8.3.22.5"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>rbuf</code></em></span></dt><dd><p> 4 Ringbuffer concerned. 5 </p></dd><dt><span class="term"><em class="parameter"><code>idx</code></em></span></dt><dd><p> 6 Packet index as returned by <code class="function"><a class="link" href="API-dvb-ringbuffer-pkt-next.html" title="dvb_ringbuffer_pkt_next">dvb_ringbuffer_pkt_next</a></code>. 7 </p></dd><dt><span class="term"><em class="parameter"><code>offset</code></em></span></dt><dd><p> 8 Offset into packet to read from. 9 </p></dd><dt><span class="term"><em class="parameter"><code>buf</code></em></span></dt><dd><p> 10 Destination buffer for data. 11 </p></dd><dt><span class="term"><em class="parameter"><code>len</code></em></span></dt><dd><p> 12 Size of destination buffer. 13 </p></dd></dl></div></div><div class="refsect1"><a name="id-1.8.3.22.6"></a><h2>Note</h2><p> 14 unlike <code class="function">dvb_ringbuffer_read</code>, this does NOT update the read pointer 15 in the ringbuffer. You must use <code class="function"><a class="link" href="API-dvb-ringbuffer-pkt-dispose.html" title="dvb_ringbuffer_pkt_dispose">dvb_ringbuffer_pkt_dispose</a></code> to mark a 16 packet as no longer required. 17</p></div><div class="refsect1"><a name="id-1.8.3.22.7"></a><h2>Description</h2><p> 18 returns Number of bytes read, or -EFAULT. 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-dvb-ringbuffer-pkt-write.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch06s02.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-dvb-ringbuffer-pkt-read.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">dvb_ringbuffer_pkt_write</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">dvb_ringbuffer_pkt_read</span></td></tr></table></div></body></html> 20