You are right Sam, I am running RedHat 9. "tnslsnr" and "tnslsnr0" both do exist in the $ORACLE_HOME/bin directory. ping localhost works. ping 127.0.0.1 works.

I just got her breathing. In the listener.ora file, I changed the host from HOST = localhost.localdomain to HOST = 127.0.0.1 and now the listener starts!

All your input helped me start looking in the right areas. Thanks