#include <stdio.h>#include <sys/types.h>#include <sys/socket.h>#include <sys/un.h>#include <netdb.h>#include <unistd.h>int main(int argc,char *argv[]){	int connect_fd;	int ret;	char snd_buf[1024];	int i;	int port;	int len;	static struct sockaddr_in srv_addr;	if(argc!=3){		printf("Usage: %s server_ip_address port\n",argv[0]);		return 1;	}		port=atoi(argv[2]);	connect_fd=socket(PF_INET,SOCK_STREAM,0);	if(connect_fd<0){		perror("cannot create communication socket");		return 1;	}		memset(&srv_addr,0,sizeof(srv_addr));	srv_addr.sin_family=AF_INET;	srv_addr.sin_addr.s_addr=inet_addr(argv[1]);	srv_addr.sin_port=htons(port);	ret=connect(connect_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));	if(ret==-1){		perror("cannot connect to the server");		close(connect_fd);		return 1;	}		memset(snd_buf,0,1024);	while(1){		write(STDOUT_FILENO,"input message:",14);				len=read(STDIN_FILENO,snd_buf,1024);		if(len>0)			write(connect_fd,snd_buf,len);		len=read(connect_fd,snd_buf,len);		if(len>0)			printf("Message from server: %s\n",snd_buf);				if(snd_buf[0]=='@')			break;		}		close(connect_fd);	return 0;}