CheckResolv

This is a quick'n'dirty tool for checking the configuration of your local resolver and/or DNS configuration. See the included manpage and source code for more explanations.

options

-V
display version number and exit.
-h
brief help on the command-line options.
-v
display various useless messages.
-r
do reverse lookup on IP address discovered.
-e
show content of a few environment var resolver-related.
-t
compute elapsed time of operation, not really accurate.

This software use only basic functions like gethostbyname(3) or gethostbyaddr(3). Checkresolv use the more low-level of the resolver galaxy, so it works like any "lambda" application. Really nice when you have to catch a mysterious failure in a LAMBDA software.

The environmemt variable CHECKRESOLV control the verbosity. A value of tech add the display of reverse lookup and timings. And setting to all give you all the bells'n'whistles needed by geeks.