安装libevent

1.在libevent官网（http://libevent.org/）上下载压缩包（我下载的是libevent-2.1.8-stable.tar.gz）

2.解压压缩包：tar -zxvf libevent-2.1.8-stable.tzr.gz

3.进入新生成的目录中：cd libevent-2.1.8-stable

4.配置安装库的目标路径：./configure --prefix=/usr

报错:configure: error: openssl is a must but can not be found. You should add the directory containing ‘openssl.pc’ to the PKG_CONFIG_PATH’ environment variable, or set ‘CFLAGS’ and ‘LDFLAGS’ directly for openssl, or use ‘–disable-openssl’ to disable support for openssl encryption
运行:sudo apt install libssl-dev
5.编译安装libevent库：（1）make （2）sudo make install

6.检测安装是否成功：ls -al /usr/lib | grep libevent