Sometimes we can see that the nagios configuration is completely correct but it returns a (NULL) like the following. This happens because it cannot find the path where the plugin is hosted.
To fix this error all we would have to do is edit the plugin.
We are looking for this line
use lib "/usr/local/nagios/libexec";
And we change it to where we have the plugins hosted, in my case:
use lib «/usr/lib/nagios/plugins»;
Regards, rokitoh
:wq!
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