server.c

简单的服务器

/******* 服务器程序 (server.c) ************/ 
#include  <stdio.h>
#include  <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include  <string.h>
#include <netinet/in.h>
#include <errno.h>
//#include 

int main(int argc, char *argv[]) 
{ 
int sockfd,new_fd; 
struct sockaddr_in server_addr; 
struct sockaddr_in client_addr; 
int sin_size,portnumber; 
char hello[]="Hello! Are You Fine?\n"; 

if(argc!=2) 
{ 
fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]); 
exit(1); 
} 

if((portnumber=atoi(argv[1]))<0) 
{ 
fprintf(stderr,"Usage:%s portnumber\a\n",argv[0]); 
exit(1); 
} 

/* 服务器端开始建立socket描述符 */ 
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(&server_addr,sizeof(struct sockaddr_in)); 
server_addr.sin_family=AF_INET; 
server_addr.sin_addr.s_addr=htonl(INADDR_ANY); 
server_addr.sin_port=htons(portnumber); 

/* 捆绑sockfd描述符 */ 
if(bind(sockfd,(struct sockaddr *)(&server_addr),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); 
} 

while(1) 
{ 
/* 服务器阻塞,直到客户程序建立连接 */ 
sin_size=sizeof(struct sockaddr_in); 
if((new_fd=accept(sockfd,(struct sockaddr *)(&client_addr),&sin_size))==-1) 
{ 
fprintf(stderr,"Accept error:%s\n\a",strerror(errno)); 
exit(1); 
} 

fprintf(stderr,"Server get connection from %s\n", 
inet_ntoa(client_addr.sin_addr)); 
if(write(new_fd,hello,strlen(hello))==-1) 
{ 
fprintf(stderr,"Write Error:%s\n",strerror(errno)); 
exit(1); 
} 
/* 这个通讯已经结束 */ 
close(new_fd); 
/* 循环下一个 */ 
} 
close(sockfd); 
exit(0); 
}