trivial changes to Perl plugin section.

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@924 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 12 insertions, 7 deletions

diff --git a/doc/developer-guidelines.sgml b/doc/developer-guidelines.sgml
index 064bd92..9ec3f94 100644
--- a/doc/developer-guidelines.sgml
+++ b/doc/developer-guidelines.sgml
@@ -407,12 +407,12 @@
                 <orderedlist>
                         
                         <listitem><para> Do not use BEGIN and END blocks since they will be called 
-                        the first time and when Nagios shuts down with Embedded Perl (ePN).  In 
+                        only once (when Nagios starts and shuts down) with Embedded Perl (ePN).  In 
                         particular, do not use BEGIN blocks to initialize variables.</para>
                         </listitem>
           
                         <listitem><para>To use utils.pm, you need to provide a full path to the
-                        module in order for it to work with ePN.</para>
+                        module in order for it to work.</para>
                         
           <literallayout>
           e.g.
@@ -429,16 +429,18 @@
                         variable. </para>
                         
 
-                        <para>Explicitly initialize each varialable in use.  Otherwise with
-                        caching enabled, the plugin will not be recompilied each time, and
+                        <para>Explicitly initialize each variable in use.  Otherwise with
+                        caching enabled, the plugin will not be recompiled each time, and
                         therefore Perl will not reinitialize all the variables.  All old
                         variable values will still be in effect.</para>
                         </listitem>
                         
-                        <listitem><para>Do not use &gt; DATA &lt; (these simply do not compile under ePN).</para>
+                        <listitem><para>Do not use &gt;DATA&lt; handles (these simply do not compile under ePN).</para>
                         </listitem>
 
-                        <listitem><para>Do not use named subroutines</para> 
+                        <listitem><para>Do not use global variables in named subroutines. This is bad practise anyway, but with ePN the
+                        compiler will report an error "&lt;global_var&gt; will not stay shared ..". Values used by
+                        subroutines should be passed in the argument list.</para> 
                         </listitem>
 
                         <listitem><para>If writing to a file (perhaps recording
@@ -449,7 +451,10 @@
                 
                         <listitem><para>As in <xref linkend="runtime"> all plugins need 
                         to monitor their runtime, specially if they are using network
-                        resources.  Use of the <emphasis>alarm</emphasis> is recommended.
+                        resources.  Use of the <emphasis>alarm</emphasis> is recommended
+                        noting that some Perl modules (eg LWP) manage timers, so that an alarm
+                        set by a plugin using such a module is overwritten by the module.
+                        (workarounds are cunning (TM) or using the module timer)
                         Plugins may import a default time out ($TIMEOUT) from utils.pm.
                         </para>
                         </listitem>