This feature allows you to associate shell or a batch scripts that perform some tasks on Hudson depending on the build log output. If the log text matches somewhere in the build log file, the script will execute. ex: if "IOException" if specified in the log text, and if the build log file contains the string "IOException", the script will execute.
Java Regex are allowed, and groups can be used as script parameters. If the text is "Last Build : #(\d+)" and the script is "script.sh", then if the log contains a line "Last Build : #4", the script "script.sh 4" will be called.