dayts.c

daytime服务

#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<netdb.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<stdio.h>
#include<time.h>

int PortNumber=13;

int dayts(); 

int dayts() 
{ 
pid_t childpid[3];
int i;
int listenfd,communfd; 
struct sockaddr_in servaddr; 
time_t tick;
char buf[256]; 

if((listenfd=socket(AF_INET,SOCK_STREAM,0))==-1) 
{ 
perror("create socket error"); 
exit(1); 
} 

servaddr.sin_family=AF_INET; 
servaddr.sin_addr.s_addr=INADDR_ANY; 
servaddr.sin_port=htons(PortNumber); 
if(bind(listenfd,(struct sockaddr *)&servaddr,sizeof(servaddr))==-1) 
{ 
perror("bind error"); 
exit(1); 
} 
if(listen(listenfd,254)==-1) 
{ 
perror("listen error"); 
exit(1); 
}
for (i = 0; i < 3; i++)
{
	if((childpid[i]=fork())==-1) 
	{ 
		perror("fork error"); 
		exit(1); 
	} 
	if(childpid[i] == 0)
	{
		while(communfd=accept(listenfd,(struct sockaddr*)NULL,NULL))
		{ 
			tick=time(NULL); 
			snprintf(buf,sizeof(buf),"%.24s\r\n",ctime(&tick)); 
			write(communfd,buf,strlen(buf)+1);
			close(communfd); 
		} 
	}
	else if( childpid[i] >0 )
		;
}
return 1;

}


int main()
{
	signal(33,dayts);
	while(1)
	{
		sleep(3);
	}
}