<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>function::user_string_n2</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="SystemTap Tapset Reference Manual"><link rel="up" href="ch17.html" title="Chapter 17. String and data retrieving functions Tapset"><link rel="prev" href="re244.html" title="function::user_string_n"><link rel="next" href="re246.html" title="function::user_string_n_warn"></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>function::user_string_n2</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re244.html">Prev</a> </td><th width="60%" align="center">Chapter 17. String and data retrieving functions Tapset</th><td width="20%" align="right"> <a accesskey="n" href="re246.html">Next</a></td></tr></table><hr></div><div class="refentry" title="function::user_string_n2"><a name="API-user-string-n2"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>function::user_string_n2 — Retrieves string of given length from user space. </p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><pre class="programlisting"> user_string_n2:string(addr:long,n:long,err_msg:string) </pre></div><div class="refsect1" title="Arguments"><a name="id3137172"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>addr</code></em></span></dt><dd><p> The user space address to retrieve the string from. </p></dd><dt><span class="term"><em class="parameter"><code>n</code></em></span></dt><dd><p> The maximum length of the string (if not null terminated). </p></dd><dt><span class="term"><em class="parameter"><code>err_msg</code></em></span></dt><dd><p> The error message to return when data isn't available. </p></dd></dl></div></div><div class="refsect1" title="Description"><a name="id3137234"></a><h2>Description</h2><p> Returns the C string of a maximum given length from a given user space address. Returns the given error message string on the rare cases when userspace data is not accessible at the given address. </p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re244.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch17.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re246.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>function::user_string_n</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>function::user_string_n_warn</span></td></tr></table></div></body></html>