#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <netdb.h>
int main(int argc, char *argv[])
{
int sockfd,connfd;
struct sockaddr_in srvaddr;
struct sockaddr_in cliaddr;
int len,port;
char hello[]="Hi,welcome to
linux-code!/n";
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
fprintf(stderr,"Socket error:%s/n/a",strerror(errno));
exit(1);
}
/* 服务器端填充 sockaddr结构 */
bzero(&srvaddr,sizeof(struct sockaddr_in));
srvaddr.sin_family=AF_INET;
srvaddr.sin_addr.s_addr=htonl(INADDR_ANY);
srvaddr.sin_port=htons(1113);
/* 捆绑sockfd描述符 */
if(bind(sockfd,(struct sockaddr *)(&srvaddr),sizeof(struct sockaddr))==-1){
fprintf(stderr,"Bind error:%s/n/a",strerror(errno));
exit(1);
}
/* 监听sockfd描述符 */
if(listen(sockfd,5)==-1){
fprintf(stderr,"Listen error:%s/n/a",strerror(errno));
exit(1);
}
len=sizeof(struct sockaddr_in);
while(1){ /* 服务器阻塞,直到客户程序建立连接 */
if((connfd=accept(sockfd,(struct sockaddr *)(&cliaddr),&len))==-1){
fprintf(stderr,"Accept error:%s/n/a",strerror(errno));
exit(1);
}
fprintf(stderr,"Server get connection from %s/n",inet_ntoa(cliaddr.sin_addr));
if(write(connfd,hello,strlen(hello))==-1){
fprintf(stderr,"Write Error:%s/n",strerror(errno));
exit(1);
}
/* 这个通讯已经结束 */
close(connfd);
/* 循环下一个 */
}
close(sockfd);
exit(0);
}
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <netdb.h>
int main(int argc, char *argv[]) {
int sockfd; char buf[1024];
struct sockaddr_in srvaddr;
struct hostent *phost; int nbytes;
if(argc!=3){
fprintf(stderr,"Usage:%s <IP> <portnumber>/a/n",argv[0]);
exit(1);
}
/* 客户程序开始建立 sockfd描述符 */
if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1){
fprintf(stderr,"socket Error:%s/a/n",strerror(errno));
exit(1);
}
/* 客户程序填充服务端的资料 */
bzero(&srvaddr,sizeof(srvaddr));
srvaddr.sin_family=AF_INET;
srvaddr.sin_port=htons(atoi(argv[2]));
if (inet_pton(AF_INET, argv[1], &srvaddr.sin_addr) <= 0){
fprintf(stderr,"inet_pton Error:%s/a/n",strerror(errno));
exit(1);
}
/* 客户程序发起连接请求 */
if(connect(sockfd,(struct sockaddr *)(&srvaddr),sizeof(struct sockaddr))==-1){
fprintf(stderr,"connect Error:%s/a/n",strerror(errno));
exit(1);
}
/* 连接成功了 */
if((nbytes=read(sockfd,buf,1024))==-1){
fprintf(stderr,"read Error:%s/n",strerror(errno));
exit(1);
}
buf[nbytes]='/0';
printf("received data:%s/n",buf);
/* 结束通讯 */
close(sockfd);
exit(0);
}
