Linux 网络编程 简单实例

//客户端,client:

#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<sys/stat.h>
#include<arpa/inet.h>
#define MAXBUF 256
int main()
{
int ssock;
int clen;
struct sockaddr_in server_addr;
char buf[MAXBUF];
if((ssock=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP))<0){
perror("socket error:");
exit(1);
}
clen = sizeof(server_addr);
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family     =AF_INET;
server_addr.sin_addr.s_addr=inet_addr("127.0.0.1");
server_addr.sin_port       =htons(7758);
if(connect(ssock,(struct sockaddr *)&server_addr,clen)<0){
perror("connect error:");
exit(1);
}
memset(buf,0,MAXBUF);
if(read(ssock,buf,MAXBUF)<=0)
{
perror("read error:");
exit(1);
}
close(ssock);
printf("\nread: %s\n",buf);
return 0;
}

//服务端,server:

#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<sys/stat.h>
#include<arpa/inet.h>
#define MAXBUF 256
int main()
{
int clen;
int ssock,csock;
struct sockaddr_in client_addr,server_addr;
char buf[MAXBUF];
if((ssock=socket(PF_INET,SOCK_STREAM,IPPROTO_TCP))<0){
perror("socket error:");
exit(1);
}
clen = sizeof(client_addr);
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family     =AF_INET;
server_addr.sin_addr.s_addr=htonl(INADDR_ANY);    server_addr.sin_port=htons(7758);
if(bind(ssock,(struct sockaddr *)&server_addr,sizeof(server_addr))<0){
perror("bind error");
exit(1);
}
if(listen(ssock,8)<0){
perror("listen error:");
exit(1);
}
while(1){
csock=accept(ssock,(struct sockaddr *)&client_addr,&clen);
if(write(csock,buf, MAXBUF)<=0)
perror("write error:");
close(csock);
}
return 0;
}

//客户端,client:

#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<sys/stat.h>
#include<arpa/inet.h>
#define MAXBUF 256
int main()
{
int ssock;
int clen;
struct sockaddr_in client_addr,server_addr;
char buf[MAXBUF];
strcpy(buf,"I miss you already!\n");
if((ssock = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))<0){
perror("socket error:\n");
exit(1);
}
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family  =AF_INET;
server_addr.sin_addr.s_addr=inet_addr("127.0.0.1");
server_addr.sin_port=htons(7758);
sendto(ssock,(void *)buf,MAXBUF,0,(struct sockaddr*)&server_addr,sizeof(server_addr));
printf("Send message:%s\n",buf);
clen=sizeof(client_addr);
recvfrom(ssock,(void *)buf,MAXBUF,0,(struct sockaddr*)&server_addr,&clen);
printf("Receive message:%s\n",buf);
close(ssock);
return 0;
}

//服务端,server:

#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<sys/stat.h>
#include<arpa/inet.h>
#define MAXBUF 256
int main()
{
int ssock;
int clen;
struct sockaddr_in client_addr,server_addr;
char buf[MAXBUF];
if((ssock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))<0){
perror("socket error:");
exit(1);
}
memset(&server_addr,0,sizeof(server_addr));
server_addr.sin_family=AF_INET;
server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
server_addr.sin_port=htons(7758);
if(bind(ssock,(struct sockaddr *)&server_addr,sizeof(server_addr))<0){
perror("bind error:");
exit(1);
}
clen=sizeof(client_addr);
recvfrom(ssock,(void *)buf,MAXBUF,0,(struct sockaddr*)&client_addr,&clen);
strcpy(buf,"I miss you");
sendto(ssock,(void *)buf,MAXBUF,0,(struct sockaddr*)&client_addr ,sizeof(client_addr));
close(ssock);
return 0;
}