#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <signal.h>
#include <netdb.h> 
#include <sys/types.h> 
#include <netinet/in.h> 
#include <sys/socket.h> 
#include <errno.h>


#define sFALSE                  0
#define sTRUE                   1

#ifndef TCP_NODELAY
  #define TCP_NODELAY 1
#endif

volatile int STOP = sFALSE;


/***************************************************************************
* signal handler. 
* CTRL-C Handler fuer sauberes beenden 
***************************************************************************/
void signal_handler_CTRL (int status)
{
    STOP=sTRUE;
    printf("\n\n SIGNAL \n\n");
} /* end funktion signal_handler_CTRL */




int main(int argc, char *argv[])
{
int                     i=0;
char                    buf[128];
char                    sbuf[] = "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
struct sockaddr_in      server;  // Socket-Adresse
struct hostent          *hp;      // Host-Info
int                     sockfd, sockoption;
int						ret;


    if ( argc < 3 ) {
        printf("Aufruf ->  dmtest ServerIP Port\n");
        exit (-1);
    }   
    /* CTRL-C Handler einhaengen */
    signal(SIGINT, signal_handler_CTRL);

    // Socket erzeugen
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if  (sockfd < 0) {
        printf ("Unable to open stream socket\n");
        exit(1); 
    } 
    
    sockoption = 1;
    if (setsockopt (sockfd, IPPROTO_TCP, TCP_NODELAY, (char *) &sockoption, sizeof(sockoption)) != 0) {
        printf("Failed to set socket option TCP_NODELAY\n");
        exit (1);
    }    

    // Hostnamen aufloesen
    server.sin_family = AF_INET;
    hp = gethostbyname(argv[1]);
    if (hp == 0) {
        printf("%s: unknown host\n", argv[1]);
        exit(1);
    }

    bcopy(hp->h_addr_list[0], &server.sin_addr, hp->h_length);
    server.sin_port = htons(atoi(argv[2]));

    // Verbindung herstellen:
    if (connect(sockfd, (struct sockaddr *)&server, sizeof(server)) < 0) {
        printf("Unable to connect stream socket\n");
        exit(1);
    } 

    while (STOP==sFALSE) {
        int     len, nleft, nread, rval;
        char    *ptr;
        /* 1.  command send 
             a)length of command at first
             b)command
           2.  receive answer
             a)lenght of answer
             b)answer
        */
        /* send the command */
printf("s"); fflush(stdout);

        /* 1a send length */
        len = strlen(sbuf); 
        rval = send(sockfd, (char *)&len, sizeof(int), 0);
        if (rval < 0 || rval != sizeof(int)) {
            printf("send Anfragelaenge fehlerhaft\n");
            break;
        }     
printf("S"); fflush(stdout);
        /* 1b send command */
        rval = send(sockfd, sbuf, len, 0);
        if (rval < 0 || rval != len) {
            printf("send Anfrage fehlerhaft\n");
            break;
        }     

printf("r"); fflush(stdout);
        /* wait for the OK-answer from Server */
        /* 2a read lenght of answer */
        nleft = sizeof(int);
        ptr = (char *) &len;
        while (nleft > 0) {
            if ( (nread = recv(sockfd, ptr, nleft, 0)) < 0) {
                printf("ERROR recv\n"); exit (2);
            } /* end if return < 0 */
            else if (nread == 0)
                break;
            nleft -= nread;
            ptr   += nread;
        } /* end while length to receive */
        if ( nleft ) {
            printf("Laenge fehlerhaft empfangen\n");
            break;
        }
        if (len < 0 || len > 128 ) {
            printf("Laenge ist falsch\n");
            break;
		}	
printf("R%d",len); fflush(stdout);
        /* 2b read answer */
        nleft = len;
        ptr = (char *) buf;
        while (nleft > 0) {
            if ( (nread = recv(sockfd, ptr, nleft, 0)) < 0) {
                printf("ERROR recv\n"); exit (2);
            } /* end if return < 0 */
            else if (nread == 0)
                break;
            nleft -= nread;
            ptr   += nread;
        } /* end while length to receive */
        if ( nleft ) {
            printf("Laenge fehlerhaft empfangen\n");
            break;
        }
		
		buf[len] = 0;
        printf("->%d->%s\n", i++,buf); fflush(stdout);
		
		
    } /* end while */

    ret = close ( sockfd );
    printf("\nENDE DMTEST\n");
    exit(1);
}