manual

GFI Network Server Monitor Writing your own monitoring functions • 173
Writing your own monitoring functions
Introduction
NOTE: GFI Support cannot assist you in the writing and debugging of
custom scripts. You must be familiar with VBscript to write your own
functions and you must debug them yourself.
GFI Network Server Monitor is designed to let operators write their
own monitor functions and use them in the product. GFI uses VBScript
because it is the most popular scripting language in Windows
environments.
GFI Network Server Monitor uses VBscript itself to perform a number
of checks. In fact, during installation, five VBScript files are installed:
• ads.vbs – includes monitor functions based on ADSI (Active
Directory Service Interfaces);
• exchange.vbs – includes monitor functions that can check
Exchange 2000/2003 servers;
• hardware.vbs – includes hardware related monitor functions;
• os.vbs – includes Operating System related monitor functions;
• sample.vbs – includes some sample functions.
Writing a script/function
GFI Network Server Monitor functions should always return:
• -1 (True); Return -1 in case the Monitor Function is successful. For
instance, if your function checks the existence of a certain
directory, and it does exist, then return -1;
• 0 (False); Return 0 in case the Monitor Function is not successful.
For instance, if your function checks the existence of a certain
directory, and it does not exist, then return 0;
• 1 (Unknown); Return 1 in case the Monitor Function cannot
determine True or False. For instance, if your function checks the
existence of a certain directory on a server, but it cannot find the
server at all (for instance because the computer is down), return 1;
It’s very easy to write your own monitor functions in VBScript. Use the
following guidelines when writing a new function:
• The routine must be a Function, not a Sub;
• The Function must return True (-1), False (0) or Unknown (1);
• Optionally, use the EXPLANATION system variable to add your
own explanation to the result of the function; this EXPLANATION
is shown in the client program each time the check is made;