<?xml version="1.0"?>
<rule version="1">
    <pattern> if \( ([!] )*?(strlen) \( \w+? \) ([>] [0] )*?\) { </pattern>
    <message>
        <id>StrlenEmptyString</id>
        <severity>performance</severity>
        <summary>Using strlen() to check if a string is empty is not efficient.</summary>
    </message>
</rule>