<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>3.6. Tapsets</title><link rel="stylesheet" href="./Common_Content/css/default.css" type="text/css" /><meta name="generator" content="publican 1.6" /><meta name="package" content="Systemtap-SystemTap_Beginners_Guide-1.0-en-US-2.0-2" /><link rel="home" href="index.html" title="SystemTap Beginners Guide" /><link rel="up" href="understanding-how-systemtap-works.html" title="Chapter 3. Understanding How SystemTap Works" /><link rel="prev" href="arrayops-aggregates.html" title="3.5.7. Computing for Statistical Aggregates" /><link rel="next" href="useful-systemtap-scripts.html" title="Chapter 4. Useful SystemTap Scripts" /></head><body class=""><p id="title"><a class="left" href="http://www.fedoraproject.org"><img src="Common_Content/images/image_left.png" alt="Product Site" /></a><a class="right" href="http://docs.fedoraproject.org"><img src="Common_Content/images/image_right.png" alt="Documentation Site" /></a></p><ul class="docnav"><li class="previous"><a accesskey="p" href="arrayops-aggregates.html"><strong>Prev</strong></a></li><li class="next"><a accesskey="n" href="useful-systemtap-scripts.html"><strong>Next</strong></a></li></ul><div class="section" title="3.6. Tapsets"><div class="titlepage"><div><div><h2 class="title" id="understanding-tapsets">3.6. Tapsets</h2></div></div></div><a id="id4374183" class="indexterm"></a><div class="para"> <em class="firstterm">Tapsets</em> are scripts that form a library of pre-written probes and functions to be used in SystemTap scripts. When a user runs a SystemTap script, SystemTap checks the script's probe events and handlers against the tapset library; SystemTap then loads the corresponding probes and functions before translating the script to C (refer to <a class="xref" href="understanding-how-systemtap-works.html#understanding-architecture-tools" title="3.1. Architecture">Section 3.1, “Architecture”</a> for information on what transpires in a SystemTap session). </div><div class="para"> Like SystemTap scripts, tapsets use the filename extension <code class="filename">.stp</code>. The standard library of tapsets is located in <code class="filename">/usr/share/systemtap/tapset/</code> by default. However, unlike SystemTap scripts, tapsets are not meant for direct execution; rather, they constitute the library from which other scripts can pull definitions. </div><div class="para"> Simply put, the tapset library is an abstraction layer designed to make it easier for users to define events and functions. In a manner of speaking, tapsets provide useful aliases for functions that users may want to specify as an event; knowing the proper alias to use is, for the most part, easier than remembering specific kernel functions that might vary between kernel versions. </div><div class="para"> Several handlers and functions in <a class="xref" href="scripts.html#systemtapscript-events" title="3.2.1. Event">Section 3.2.1, “Event”</a> and <a class="xref" href="systemtapscript-handler.html#systemtapscript-functions" title="SystemTap Functions">SystemTap Functions</a> are defined in tapsets. For example, <code class="command">thread_indent()</code> is defined in <code class="filename">indent.stp</code>. </div></div><ul class="docnav"><li class="previous"><a accesskey="p" href="arrayops-aggregates.html"><strong>Prev</strong>3.5.7. Computing for Statistical Aggregates</a></li><li class="up"><a accesskey="u" href="#"><strong>Up</strong></a></li><li class="home"><a accesskey="h" href="index.html"><strong>Home</strong></a></li><li class="next"><a accesskey="n" href="useful-systemtap-scripts.html"><strong>Next</strong>Chapter 4. Useful SystemTap Scripts</a></li></ul></body></html>
