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diff --git a/doc/src/sgml/html/plperl-event-triggers.html b/doc/src/sgml/html/plperl-event-triggers.html new file mode 100644 index 0000000..dd9fb5b --- /dev/null +++ b/doc/src/sgml/html/plperl-event-triggers.html @@ -0,0 +1,28 @@ +<?xml version="1.0" encoding="UTF-8" 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=UTF-8" /><title>44.7. PL/Perl Event Triggers</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /><link rel="prev" href="plperl-triggers.html" title="44.6. PL/Perl Triggers" /><link rel="next" href="plperl-under-the-hood.html" title="44.8. PL/Perl Under the Hood" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">44.7. PL/Perl Event Triggers</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="plperl-triggers.html" title="44.6. PL/Perl Triggers">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="plperl.html" title="Chapter 44. PL/Perl — Perl Procedural Language">Up</a></td><th width="60%" align="center">Chapter 44. PL/Perl — Perl Procedural Language</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="plperl-under-the-hood.html" title="44.8. PL/Perl Under the Hood">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="PLPERL-EVENT-TRIGGERS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">44.7. PL/Perl Event Triggers</h2></div></div></div><p> + PL/Perl can be used to write event trigger functions. In an event trigger + function, the hash reference <code class="varname">$_TD</code> contains information + about the current trigger event. <code class="varname">$_TD</code> is a global variable, + which gets a separate local value for each invocation of the trigger. The + fields of the <code class="varname">$_TD</code> hash reference are: + + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">$_TD->{event}</code></span></dt><dd><p> + The name of the event the trigger is fired for. + </p></dd><dt><span class="term"><code class="literal">$_TD->{tag}</code></span></dt><dd><p> + The command tag for which the trigger is fired. + </p></dd></dl></div><p> + </p><p> + The return value of the trigger function is ignored. + </p><p> + Here is an example of an event trigger function, illustrating some of the + above: +</p><pre class="programlisting"> +CREATE OR REPLACE FUNCTION perlsnitch() RETURNS event_trigger AS $$ + elog(NOTICE, "perlsnitch: " . $_TD->{event} . " " . $_TD->{tag} . " "); +$$ LANGUAGE plperl; + +CREATE EVENT TRIGGER perl_a_snitch + ON ddl_command_start + EXECUTE FUNCTION perlsnitch(); +</pre><p> + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="plperl-triggers.html" title="44.6. PL/Perl Triggers">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="plperl.html" title="Chapter 44. PL/Perl — Perl Procedural Language">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="plperl-under-the-hood.html" title="44.8. PL/Perl Under the Hood">Next</a></td></tr><tr><td width="40%" align="left" valign="top">44.6. PL/Perl Triggers </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 13.4 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 44.8. PL/Perl Under the Hood</td></tr></table></div></body></html>
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