While compiling nagios plugins, you can get an error given below.
==========================
check_http.c:312:9: error: ‘ssl_version’ undeclared (first use in this function)
....
make[2]: *** [check_http.o] Error 1
make[2]: Leaving directory `/usr/local/src/nagios-plugins-1.4.16/plugins'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/local/src/nagios-plugins-1.4.16'
make: *** [all] Error 2
========================
Fix :
yum install libssl-dev
yum install openssl*
Once this is installed , you will be able to compile the plugins without any issue.
