/* server-fork.c: receive hello message from client,
and fork a new process to send back "welcome" message to client*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#define MAXDATASIZE 128
#define PORT 3000
#define BACKLOG 5
int main(int argc,char **argv)
{
int sockfd,new_fd,nbytes,sin_size;
char buf[MAXDATASIZE];
struct sockaddr_in srvaddr,clientaddr;
//create socket
sockfd=socket(AF_INET,SOCK_STREAM,0);
if(sockfd==-1){
printf("can't create socket\n");
exit(1);
}
//assign socket address
bzero(&srvaddr,sizeof(srvaddr));
srvaddr.sin_family=AF_INET;
srvaddr.sin_port=htons(PORT);
if(inet_aton("127.0.0.1",&srvaddr.sin_addr)==-1){
printf("addr convert error\n");
close(sockfd);
exit(1);
}
//srvaddr.sin_addr.s_addr=htonl(INADDR_ANY);
//bind IP address and port
if(bind(sockfd,(struct sockaddr *)&srvaddr,sizeof(struct sockaddr))==-1){
printf("bind error\n");
close(sockfd);
exit(1);
}
//listen on socket
if(listen(sockfd,BACKLOG)==-1){
printf("listen error\n");
close(sockfd);
exit(1);
}
for(;;){
//accept client's connection
sin_size=sizeof(struct sockaddr_in);
if((new_fd=accept(sockfd,(struct sockaddr *)&clientaddr,&sin_size))==-1){
printf("accept errot\n");
continue;
}
//dump client's IP address and port number
printf("client ip:%s\n",inet_ntoa(clientaddr.sin_addr));
printf("client port:%d\n",ntohs(clientaddr.sin_port));
//receive message
nbytes=read(new_fd,buf,MAXDATASIZE);
buf[nbytes]='\0';
printf("client:%s\n",buf);
if (!fork()) { //child process
close(sockfd);
//send message
bzero(buf,sizeof(buf));
sprintf(buf,"welcome!");
write(new_fd,buf,strlen(buf));
close(new_fd);
exit(0);
}
//close socket
close(new_fd);
}
//close socket
close(sockfd);
return 0;
}
