webserver.c

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

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

#define APP_MAX_BUFFER 1024
#define PORT 8080

int main() {
  // Server and Client File Descriptors
  int server_fd, client_fd;

  // socked address
  struct sockaddr_in address;
  int address_len = sizeof(address);

  // Buffer array to store client data
  // copy data from kernel
  char buffer[APP_MAX_BUFFER] = {0};

  // Server Socked
  // SOCK_STREAM -> TCP
  if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    perror("Socked creating failed");
    exit(EXIT_FAILURE);
  }

  address.sin_family = AF_INET;         // IPv4
  address.sin_addr.s_addr = INADDR_ANY; // 0.0.0.0
  address.sin_port = htons(PORT);

  if (bind(server_fd, (const struct sockaddr *)&address, address_len) < 0) {
    perror("Faild to bind socked and address");
    exit(EXIT_FAILURE);
  }

  // Creates the queues
  // Listen for clients, with 10 backlog (10 connection in accept queue)
  if (listen(server_fd, 10) < 0) {
    perror("Listen failed");
    exit(EXIT_FAILURE);
  }

  while (1) {
    printf("\nWaiting for a connection...\n");

    // Accept a client connection
    if ((client_fd = accept(server_fd, (struct sockaddr *)&address,
                            (socklen_t *)(&address_len))) < 0) {
      perror("Accpet failed");
      exit(EXIT_FAILURE);
    }

    // read data from OS receive buffer to the application (buffer)
    read(client_fd, buffer, APP_MAX_BUFFER);

    printf("%s\n", buffer);

    char *http_response = "HTTP/1.1 200 OK\r\n"
                          "Content-Type: text/html\r\n"
                          "Content-Length: 7\r\n" // more bytes then data
                          "\r\n"
                          "Hello\r\n";


    write(client_fd, http_response, strlen(http_response));

    close(client_fd);
  }

  return 0;
}