socket记录

文章：

http://blog.youkuaiyun.com/hguisu/article/details/7445768/

程序：

客户端：

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <string.h>

#include <netdb.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <sys/socket.h>

#include <unistd.h>

#define SERVPORT 3333

#define MAXDATASIZE 100    /*每次最大数据传输量 */

int main(int argc, char *argv[])

{

int sock_fd, recvbytes;

char buf[MAXDATASIZE];

struct hostent *host;

struct sockaddr_in serv_addr;

if(argc< 2) {

fprintf(stderr,"Please enter the server's hostname!\n");

exit(1);

}

printf("%s", argv[1]);

if((host=gethostbyname("Mac-mini3.local")) == NULL) {

herror("gethostbyname出错！");

exit(1);

}

if((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {

perror("socket创建出错！");

exit(1);

}

serv_addr.sin_family=AF_INET;

serv_addr.sin_port=htons(SERVPORT);

serv_addr.sin_addr = *((struct in_addr *)host->h_addr);

bzero(&(serv_addr.sin_zero),8);

if(connect(sock_fd, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr)) == -1) {

perror("connect出错！");

exit(1);

}

//send

int retlen = ::send(sock_fd, "ok", 3, 0);

if (retlen < 0)

{

printf("\n send error");

}

//recv

if((recvbytes=recv(sock_fd, buf, MAXDATASIZE, 0)) == -1) {

perror("recv出错！");

exit(1);

}

buf[recvbytes] = '\0';

printf("Received: %s",buf);

close(sock_fd);

}

服务端：

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <string.h>

#include <sys/types.h>

#include <netinet/in.h>

#include <sys/socket.h>

#include <sys/wait.h>

#include <unistd.h>

#include <arpa/inet.h>

#define SERVPORT 3333    /*服务器监听端口号 */

#define BACKLOG 10    /* 最大同时连接请求数 */

int main()

{

int sock_fd,client_fd;    /*sock_fd：监听socket；client_fd：数据传输socket */

socklen_t sin_size;

struct sockaddr_in my_addr;    /* 本机地址信息 */

struct sockaddr_in remote_addr;    /* 客户端地址信息 */

if((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {

perror("socket创建出错！");

exit(1);

}

my_addr.sin_family=AF_INET;

my_addr.sin_port=htons(SERVPORT);

my_addr.sin_addr.s_addr = INADDR_ANY;

bzero(my_addr.sin_zero,8);

if(bind(sock_fd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) {

perror("bind出错！");

exit(1);

}

if(listen(sock_fd, BACKLOG) == -1) {

perror("listen出错！");

exit(1);

}

while(1) {

sin_size = sizeof(struct sockaddr_in);

if((client_fd = accept(sock_fd, (struct sockaddr *)&remote_addr, &sin_size)) == -1) {

perror("accept出错");

continue;

}

//recv

char buff[3];

if(recv(client_fd, buff, 3, 0) == -1)

{

printf("recv error");

}

printf("%s\n", buff);

//send

printf("received a connection from %s\n", inet_ntoa(remote_addr.sin_addr));

if(!fork()) {    /* 子进程代码段 */

if(send(client_fd, "Hello, you are connected!\n", 26, 0) == -1) {

perror("send出错！");

}

close(client_fd);

exit(0);

}

close(client_fd);

}

}