Question

I have made a simple server that will print to the terminal when a message has been received along with the message. The client I made just sends the message (doesn’t receive) when I telnet and send messages to the server it works great and prints exactly what I sent. However when I write the C Client code found below its as if nothing is sent.

here is my compile output for the code below with -wall -wextra -pedantic

  ./client.c: In function ‘main’:
./client.c:17:4: warning: implicit declaration of function ‘bzero’ [-Wimplicit-function-declaration]
./client.c:19:4: warning: implicit declaration of function ‘inet_addr’ [-Wimplicit-function-declaration]
./client.c:28:2: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
./client.c:28:41: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default]
./client.c:22:8: warning: unused variable ‘val’ [-Wunused-variable]
./client.c:10:15: warning: unused variable ‘n’ [-Wunused-variable]
./client.c:8:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
./client.c:8:26: warning: unused parameter ‘argv’ [-Wunused-parameter]
soup@soup-XPS-8300:/home/c_dev/p2pcrypt_server/v0.1.0/src/tool_tests/libev

–

/* Sample TCP client */

#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>

int main(int argc, char**argv)
{
   int sockfd,n;
   struct sockaddr_in servaddr;
   char * sendline;
   sendline = "hello";

   sockfd=socket(AF_INET,SOCK_STREAM,0);

   bzero(&servaddr,sizeof(servaddr));
   servaddr.sin_family = AF_INET;
   servaddr.sin_addr.s_addr=inet_addr("127.0.0.1");
   servaddr.sin_port=htons(8018);

    int connect_status = connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    printf("%d\n", connect_status);

    int send_status = send(sockfd,sendline,strlen(sendline),0);
    printf("%d\n", send_status);

    printf("END\n");
    return 0;
}

Updated code
Connect returns “0” (success) and send returns “5” (i think thats how many successfull characters it sent)

Answer 1

Here is the successfully working code on my end it seems the \r\n was needed and all the great suggestions that was pointed out. Thanks mates!

/* Sample TCP client */

#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>

int main(int argc, char**argv)
{
   int sockfd,n;
   struct sockaddr_in servaddr;
   char * sendline;
   sendline = "hellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellohellolohellohellohellohellohellohellohellohellohellolohellohellohellohellohellohellohellohellohellolohellohellohellohellohellohellohellohellohellolo\r\n";

   sockfd=socket(AF_INET,SOCK_STREAM,0);

   memset(&servaddr, 0, sizeof(servaddr));
   servaddr.sin_family = AF_INET;
   servaddr.sin_addr.s_addr=inet_addr("127.0.0.1");
   servaddr.sin_port=htons(8018);

    int connect_status = connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    printf("%d\n", connect_status);

    int send_status = send(sockfd,sendline,strlen(sendline),0);
    printf("%d\n", send_status);

    printf("END\n");
    return 0;
}