client.c

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

int main()
{
    int sockfd;
    int len;
    struct sockaddr_in address;
    int result;
    char ch='A';
    sockfd=socket(AF_INET, SOCK_STREAM, 0);

    address.sin_family= AF_INET;
    address.sin_addr.s_addr = inet_addr("127.0.0.1");
    address.sin_port=9734;
    len = sizeof(address);

    result = connect(sockfd, (struct sockaddr *) &address, len);

    if(result == -1)
    {
        perror("oops:error");
        exit(1);
    }
    write(sockfd, &ch, 1);
    read(sockfd, &ch, 1);

    printf("char from server =%c",ch);
    close(sockfd);
    exit(0);
}