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

#define PORT 3490
#define MAXDATASIZE 100

int main(int argc, char *argv[])
{
    int sockfd, numbytes, sr;  
    char buf[MAXDATASIZE];
    struct sockaddr_in their_addr;
    fd_set readfds, rds;
    char sbuf[MAXDATASIZE]; int sbuf_pos=0;

    if (argc != 2) {
        fprintf(stderr,"usage: client hostip\n");
        exit(1);
    }

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

    their_addr.sin_family = AF_INET;
    their_addr.sin_port = htons(PORT);
    if (inet_pton(AF_INET, argv[1], 
		  &their_addr.sin_addr) <= 0) {
      perror("inet_pton");
      exit(1);
    }
    memset(&(their_addr.sin_zero), '\0', 8);

    if (connect(sockfd, 
		(struct sockaddr *)&their_addr, 
		sizeof(struct sockaddr)) == -1) {
        perror("connect");
        exit(1);
    }

    FD_ZERO( &readfds );
    FD_SET( 0, &readfds );
    FD_SET( sockfd, &readfds );
    
    while ( 1 ) 
      {
	rds = readfds;
	sr = select( sockfd + 1, &rds, NULL, NULL, NULL );
	
	if ( sr == -1 )
	  perror( "select" );
	else if ( sr )
	  {
	    
	    /* Data from standard input ? */
	    if ( FD_ISSET( 0, &rds ) )
	      {
		char input;
		int r;
		if ( ( r = read( 0, &input, 1 ) ) == 1 )
		  {
		    if ( send( sockfd, &input, 1, 0 ) == -1 )
		      {
			perror( "send" );
			exit( -1 );
		      }
		  }
		else if ( r == 0 )
		  break;
	      }

	    /* Data from socket ? */
	    else if ( FD_ISSET( sockfd, &rds ) )
	      {
		char input;
		if ( ( numbytes = recv( sockfd, 
					&input, 
					1, 0 ) ) == -1 )
		  {
		    perror( "recv" );
		    exit( -1 );
		  }
		else if ( numbytes == 0 )
		  {
		    puts( "Connection closed by peer.\n" );
		    break;
		  }
		else
		  {
		    putchar( input );
		  }
	      }
	  }
	
      }

    close(sockfd);

    return 0;
}


/* author: Gustavo Sverzut Barbieri (http://www.gustavobarbieri.com.br) */