accept的第三个参数，在调用之前需要设置为第二个参数的长度。在manpage中有明确的说明：
The addrlen argument is a value-result argument: the caller must ini‐tialize it to contain the size (in bytes) of the structure pointed to by addr; on return it will contain the actual size of the peer address.
CentOS 5.8上安装PHP软件提示“configure:error:no acceptable c：http://www.linuxdiyf.com/linux/11999.html