服务器端先初始化Socket，然后与端口绑定(bind)，对端口进行监听(listen)，调用accept阻塞，等待客户端连接。在这时如果有个客户端初始化一个Socket，然后连接服务器(connect)，如果连接成功，这时客户端与服务器端的连接就建立了。客户端发送数据请求，服务器端接收请求并处理请求，然后把回应数据发送给客户端，客户端读取数据，最后关闭连接，一次交互结束。 如果只是模拟http请求的话，我们实现客户端就可以了。代码如下：
#include <stdio.h> #include <stdlib.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <sys/types.h> #include <string.h> char *http_header = "GET / HTTP/1.1\r\n" "Host: www.idoushuo.com\r\n" "Connection: keep-alive\r\n" "Accept: */*\r\n" "Connection: close\r\n" "\r\n"; char *hostname = "www.idoushuo.com"; int main(){ struct sockaddr_in addr; memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(80); struct hostent *hp; hp = gethostbyname(hostname); memcpy(&addr.sin_addr, hp->h_addr, hp->h_length); int sockfd = socket(AF_INET, SOCK_STREAM, 0); int ret = connect(sockfd, (struct sockaddr *)&addr, sizeof(addr)); //send send(sockfd, http_header, strlen(http_header), 0); //recv ssize_t length = 0; char buf[101]; memset(buf, 0, sizeof(buf)); char *response = calloc(1, sizeof(char)); do{ length = recv(sockfd, buf, 100, 0); if(length){ //leak mem char *pp = realloc(response, strlen(response)+length+1); if(!pp){ break; } response = pp; memcpy(response + strlen(response), buf, length); memset(buf, 0x0, sizeof(buf)); } }while(length != 0); printf("%s\n", response); free(response); }参考 1. http://www.cnblogs.com/bai-jimmy/p/5421007.html 2. http://blog.csdn.net/hguisu/article/details/7445768/
