编译libevent

https://github.com/libevent/libevent.git

https://github.com/libevent/libevent/blob/master/Documentation/Building.md#building-on-unix-cmake

从github上下载libevent的源码

./autogen.sh
./configure
make

第一步autogen.sh的时候可能会提示下面的错误：

- aclocal: not found 安装automake

- error: Libtool library used but 'LIBTOOL' is undefined 安装libtool

- 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 安装libssl-dev

在make过程中，需要openssl相关的东西，这个无法通过源安装，只能下载源码编译

openssl安装完成后，再 make ，然后 make install 就可以了