network3w_echopc.c

/*
pineoc, 2015-03-16
week 3 network programming
iterative echo server & client
perfect version
client code
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 1024
void error_handling(char* msg);

int main(int argc,char* argv[])
{
	int sock;
	char msg[BUF_SIZE];
	int str_len,recv_len,recv_cnt;
	struct sockaddr_in serv_addr;

	if(argc!=3)
	{
		printf("Usage : %s <IP> <port> \n",argv[0]);
        exit(1);
	}

	sock = socket(PF_INET,SOCK_STREAM,0);
    if(sock==-1)
        error_handling("socket() err");
 
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));
 
    if(connect(sock,(struct sockaddr*)&serv_addr,sizeof(serv_addr))==-1)
        error_handling("connect() err");
    else
    	puts("connected.......");

    while(1)
    {
    	fputs("Input msg(Q to quit)",stdout);
    	fgets(msg,BUF_SIZE,stdin);

    	if((!strcmp(msg,"q\n")) || !strcmp(msg,"quit\n"))
    		break;

    	str_len = write(sock,msg,strlen(msg));
        recv_len=0;
        while(recv_len<str_len)
        {
            recv_cnt=read(sock,&msg[recv_len],BUF_SIZE-1);
            if(recv_len==-1)
                error_handling("read() err");
            recv_len+=recv_cnt;
        }
    	msg[str_len]=0;
    	printf("msg from server : %s",msg);
    }
    close(sock);
	return 0;
}

void error_handling(char* msg)
{
    fputs(msg,stderr);
    fputc('\n',stderr);
    exit(1);
}