错误情形：
[root@localhost ~]# /usr/local/nagios/libexec/check_mysql -h
/usr/local/nagios/libexec/check_mysql: error while loading shared libraries: libmysqlclient.so.18: cannot open shared object file: No such file or directory
解决方法：当然是针对我的虚拟机情形
利用命令：[root@238-lamp ld.so.conf.d]# find / -name libmysqlclient.so.18
/usr/local/mysql/lib/libmysqlclient.so.18
/home/oldboy/tools/mysql-5.6.10/libmysql/libmysqlclient.so.18
将/usr/local/mysql/lib（mysql的安装目录）路径加到/etc/ld.so.conf中
[root@238-lamp ld.so.conf.d]# vi /etc/ld.so.conf
include ld.so.conf.d/*.conf
/usr/local/lib
/usr/local/mysql/lib
~
~
~
"/etc/ld.so.conf" 4L, 90C written
[root@238-lamp ld.so.conf.d]# ldconfig（生效命令）
[root@238-lamp ld.so.conf.d]# /usr/local/nagios/libexec/check_mysql -h
check_mysql v1.4.16 (nagios-plugins 1.4.16)
Copyright (c) 1999-2016 Nagios Plugin Development Team
<nagiosplug-devel@lists.sourceforge.net>
This program tests connections to a MySQL server
Usage:
check_mysql [-d database] [-H host] [-P port] [-s socket]
[-u user] [-p password] [-S]
Options:
-h, --help
Print detailed help screen
-V, --version
Print version information
-H, --hostname=ADDRESS
Host name, IP Address, or unix socket (must be an absolute path)
-P, --port=INTEGER
Port number (default: 3306)
-s, --socket=STRING
Use the specified socket (has no effect if -H is used)
-d, --database=STRING
Check database with indicated name
-u, --username=STRING
Connect using the indicated username
-p, --password=STRING