System commands
- cmd= ping : execute a ‘ping’ command on the machine where JabberWatcher runs. Arguments are :
- host : the host to ping
- displaySuccess : [true/false]. True if a message should be return when host is alive.

- cmd=ps : execute the ‘ps’ unix command. Works only under UNIX systems. Arguments are :
- arg : ps arguments (ex : cmd=ps arg=aux).

- cmd=diskfree : execute the ‘df’ UNIX command.

- cmd=uptime : get the uptime of the machine (execute the ‘uptime’ machine).