libnpcommon.a(sslutils.o): In function `np_net_ssl_init_with_hostname_version_and_cert':
/root/nagios-plugins-2.2.1/plugins/sslutils.c:125: undefined reference to `SSLv23_client_method'
/root/nagios-plugins-2.2.1/plugins/sslutils.c:129: undefined reference to `SSL_library_init'
/root/nagios-plugins-2.2.1/plugins/sslutils.c:130: undefined reference to `SSL_load_error_strings'
/root/nagios-plugins-2.2.1/plugins/sslutils.c:131: undefined reference to `OPENSSL_add_all_algorithms_conf'
/root/nagios-plugins-2.2.1/plugins/sslutils.c:68: undefined reference to `SSLv3_client_method'
/root/nagios-plugins-2.2.1/plugins/sslutils.c:60: undefined reference to `SSLv2_client_method'
collect2: ld returned 1 exit status
已经执行过yum -y gd gd-devel *openssl*
但重新编译任然报上述错误。
原来是我安装的nagios-plugins版本是2.2.1，而yum安装的OpenSSL的版本只有1.0.1e，而1.0.1e是一个比较落后的版本，一些新功能函数没包含。
所以我升级了我的OpenSSL到1.1.1b之后就正常安装了。