<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>exit</title><link rel="stylesheet" type="text/css" href="rivet.css"><meta name="generator" content="DocBook XSL Stylesheets V1.79.1"><link rel="home" href="index.html" title="Apache Rivet 3.0"><link rel="up" href="commands.html" title="Rivet Tcl Commands and Variables"><link rel="prev" href="escape_string.html" title="escape_string"><link rel="next" href="headers.html" title="headers"></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">exit</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="escape_string.html"><img src="images/prev.png" alt="Prev"></a> </td><th width="60%" align="center">Rivet Tcl Commands and Variables</th><td width="20%" align="right"> <a accesskey="n" href="headers.html"><img src="images/next.png" alt="Next"></a></td></tr></table></div><div class="refentry"><div class="refentry.separator"><hr></div><a name="exit"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>exit — terminate execution and child process</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis" style="width:80%"><div style="border: 1px solid #282; margin:1ex ; padding:.4ex; padding-left: 0.8ex;   word-spacing:1ex "><span style="font-weight:bold ; font-family:monospace">::rivet::exit</span>  ?<span style="font-family:monospace; font-weight: bold;">code</span>?</div></div></div><div class="refsect1"><a name="idm45412676855904"></a><h2>Description</h2><p style="width:90%">
				Replaces Tcl's <span style="font-family:monospace"><span class="command"><strong>exit</strong></span></span> core command. <span style="font-family:monospace"><span class="command"><strong>::rivet::exit</strong></span></span>
				interrupts execution of the current script and passes execution to AbortScript if
				such script is set. After AbortScript has finished and request processing completed
				the child process is forced to exit by calling Tcl_Exit producing the same final
				effect of the core command. During an <span style="font-family:monospace"><span class="command"><strong>AbortScript</strong></span></span> execution the
				exit condition can be detected
				</p><pre class="programlisting">if {[<span style="font-family:monospace"><span class="command"><strong>::rivet::abort_page -exiting</strong></span></span>]} {
...handle exit condition
}</pre><p style="width:90%">
			</p><p style="width:90%">
				<span style="font-family:monospace"><span class="command"><strong>::rivet::exit</strong></span></span> has a single optional argument  ?<span style="font-family:monospace; font-weight: bold;">code</span>?. This 
				value must be a positive integer number to be passed to Tcl_Exit. If any other value is
				given  ?<span style="font-family:monospace; font-weight: bold;">code</span>? is set to 0. The exit code can be obtained from the dictionary
				returned by <span style="font-family:monospace"><span class="command"><strong>::rivet::abort_code</strong></span></span>
			</p><pre class="programlisting">[::rivet::abort_code]
&lt;== return_code  ?<span style="font-family:monospace; font-weight: bold;">code</span>? error_code exit</pre><p style="width:90%">
				We support this command in order to have a gentle way to terminate a request processing
				before actually exit the child process and avoid an abrupt interruption of a request that
				might leave an application in a inconsistent state. In some cases <span style="font-family:monospace"><span class="command"><strong>::rivet::exit</strong></span></span>
				could be the only way to exit a process and force the Apache HTTP web server to start
				a fresh one. Moreover the core <span style="font-family:monospace"><span class="command"><strong>exit</strong></span></span> could be called from third parties
				software and you may not be aware of it. We thus decided to trap this command and give it 
				the most gentle behavior still preserving the its basic purpose.
			</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Note"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="images/note.png"></td><th align="left">Note</th></tr><tr><td align="left" valign="top">
				Nonetheless we discourage the programmer to use such command, and suggest to focus on proper
				application design and avoid such a drastic way to bail out. 
				If you need to restart the child processes from time to time we recommend to check the 
				MaxRequests parameter in the 
				<a class="ulink" href="https://httpd.apache.org/docs/2.4/mod/prefork.html" target="_top">prefork MPM documentation</a>
				or the 
				<a class="ulink" href="http://httpd.apache.org/docs/2.0/mod/mpm_common.html#maxrequestsperchild" target="_top">MaxRequestsPerChild</a>
				configuration parameter
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