Miscellany

Simple client/server test apps

This combination doesn't seem to work when using g_io_channel_write_chars etc. No message is printed out by the server, though it does terminate at a CR at the end of typing the message.

The "standard" version works fine.  The message is printed out.

I assume I'm missing something basic here...

I apologise for the messy code! I just want to get this working before tuning too much

Thanks for looking.



/* CLIENT PROGRAMME */
//gcc -Wall -g clientgtk.c -o clientgtk `pkg-config --cflags gtk+-2.0` `pkg-config --libs gtk+-2.0` 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>  /*for memeset*/
#include <strings.h> /*for bcopy? */
#include <unistd.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <glib.h>

void error(char *msg)
{
    perror(msg);
    exit(0);
}


int main(int argc, char *argv[])
{
    int sockfd, portno, n;
    struct sockaddr_in serv_addr;
    struct hostent *server;

    GIOChannel *netchan;

        GIOStatus ret;
        GError *err = NULL;
        gsize len;
	gchar *enc;

    char buffer[256];
    if (argc < 3) {
       fprintf(stderr,"usage %s hostname port\n", argv[0]);
       exit(0);
    }
    portno = atoi(argv[2]);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) 
        error("ERROR opening socket");
    server = gethostbyname(argv[1]);
    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }
    memset((char *) &serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    bcopy((char *)server->h_addr, 
         (char *)&serv_addr.sin_addr.s_addr,
         server->h_length);
    serv_addr.sin_port = htons(portno);
    if (connect(sockfd,&serv_addr,sizeof(serv_addr)) < 0) 
        error("ERROR connecting");

/*
USING THIS SECTION DOESN'T SEEM TO WORK?!
server activates and reports client details, but no message text
client reports 34 bytes sent

Encoding reports as UTF-8
*/
    netchan = g_io_channel_unix_new(sockfd);	

    enc = g_io_channel_get_encoding(netchan);
    printf ("Encoding %s .\n", enc);
    
    printf("Please enter the message: ");
    memset(buffer,0,256);
    fgets(buffer,255,stdin);	

    ret = g_io_channel_write_chars (netchan, buffer, -1, &len, &err);
    if (ret == G_IO_STATUS_ERROR)
           g_error ("Error writing: %s\n", err->message);

    printf ("Wrote %u bytes.\n", len);



/*USING THIS SECTION INSTEAD WORKS. 
Text entered is recieved and printed out */
/*
    printf("Please enter the message: ");
    memset(buffer,0,256);
    fgets(buffer,255,stdin);
    n = write(sockfd,buffer,strlen(buffer));
    if (n < 0) 
         error("ERROR writing to socket");
*/

/*SECTION UNUSED FOR NOW - NO RESPONSE SENT FROM SERVER    
    memset(buffer,0,256);
    n = read(sockfd,buffer,255);
    if (n < 0) 
         error("ERROR reading from socket");
    printf("%s\n",buffer);

*/
    return 0;
}





//SERVER PROGRAMME
//gcc -Wall -o server server.c

/* A simple server in the internet domain using TCP
   The port number is passed as an argument */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>  /*for memset*/
#include <unistd.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

void error(char *msg)
{
    perror(msg);
    exit(1);
}

int main(int argc, char *argv[])
{
     int sockfd, newsockfd, portno, clilen;
     char buffer[256];
     struct sockaddr_in serv_addr, cli_addr;
     int n;
     int len;	

     if (argc < 2) {
         fprintf(stderr,"ERROR, no port provided\n");
         exit(1);
     }
     sockfd = socket(AF_INET, SOCK_STREAM, 0);
     if (sockfd < 0) 
        error("ERROR opening socket");
     memset((char *) &serv_addr, 0, sizeof(serv_addr));
     portno = atoi(argv[1]);
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_addr.s_addr = INADDR_ANY;
     serv_addr.sin_port = htons(portno);
     if (bind(sockfd, (struct sockaddr *) &serv_addr,
              sizeof(serv_addr)) < 0) 
              error("ERROR on binding");
     listen(sockfd,5);
     clilen = sizeof(cli_addr);
     newsockfd = accept(sockfd, 
                 (struct sockaddr *) &cli_addr, 
                 &clilen);
     if (newsockfd < 0) 
          error("ERROR on accept");


    printf("Handling client IP of: %s\n",inet_ntoa(cli_addr.sin_addr));
    printf("Client Port: %hu\n", ntohs(cli_addr.sin_port));


     memset(buffer,0,256);
     n = read(newsockfd,buffer,255);
     if (n < 0) error("ERROR reading from socket");
     len = strlen(buffer);
     printf("length: %u\n",len);
     printf("Here is the message: %s\n",buffer);
     
//RESPONSE NOT USED FOR NOW
/*
n = write(newsockfd,"I got your message",18);
     if (n < 0) error("ERROR writing to socket");
*/

     return 0; 
}