/usr/nagios/bin/nagios -v /etc/nagios.cfg

Nagios 2.10
Copyright (c) 1999-2007 Ethan Galstad (http://www.nagios.org)
Last Modified: 10-21-2007
License: GPL

Reading configuration data...

Error: Service description, host name, or check command is NULL
Error: Could not register service (config file '/etc/nagios/config.cfg', starting on line 35)

***> One or more problems was encountered while processing the config files...

     Check your configuration file(s) to ensure that they contain valid
     directives and data defintions.  If you are upgrading from a previous
     version of Nagios, you should be aware that some variables/definitions
     may have been removed or modified in this version.  Make sure to read
     the HTML documentation regarding the config files, as well as the
     'Whats New' section to find out what has changed.