simple response server

server.c

 
// webserver.c
// https://bruinsslot.jp/post/simple-http-webserver-in-c/
#include <arpa/inet.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <unistd.h>
#include <signal.h>

#define PORT 8080
#define BUFFER_SIZE 1024


int main() {
  // sigaction(SIGPIPE, &(struct sigaction){SIG_IGN}, NULL);

    signal(SIGPIPE, SIG_IGN);
  char buffer[BUFFER_SIZE];

  // Create a socket
  int sockfd = socket(AF_INET, SOCK_STREAM, 0);
  if (sockfd == -1) {
    perror("webserver (socket)");
    return 1;
  }
  printf("socket created successfully\n");

  // Create the address to bind the socket to
  struct sockaddr_in host_addr;
  int host_addrlen = sizeof(host_addr);

  host_addr.sin_family = AF_INET;
  host_addr.sin_port = htons(PORT);
  host_addr.sin_addr.s_addr = htonl(INADDR_ANY);

  // Create client address
  struct sockaddr_in client_addr;
  int client_addrlen = sizeof(client_addr);

  // Bind the socket to the address
  if (bind(sockfd, (struct sockaddr*)&host_addr, host_addrlen) != 0) {
    perror("webserver (bind)");
    return 1;
  }
  printf("socket successfully bound to address\n");

  // Listen for incoming connections
  if (listen(sockfd, SOMAXCONN) != 0) {
    perror("webserver (listen)");
    return 1;
  }
  printf("server listening for connections\n");

  for (;;) {
    // Accept incoming connections
    int newsockfd =
        accept(sockfd, (struct sockaddr*)&host_addr, (socklen_t*)&host_addrlen);
    if (newsockfd < 0) {
      perror("webserver (accept)");
      continue;
    }
    printf("connection accepted\n");

    // Get client address
    int sockn = getsockname(newsockfd, (struct sockaddr*)&client_addr,
                            (socklen_t*)&client_addrlen);
    if (sockn < 0) {
      perror("webserver (getsockname)");
      continue;
    }

    // Read from the socket
    int valread = read(newsockfd, buffer, BUFFER_SIZE);
    if (valread < 0) {
      perror("webserver (read)");
      continue;
    }

    // Read the request
    char method[BUFFER_SIZE], uri[BUFFER_SIZE], version[BUFFER_SIZE];
    sscanf(buffer, "%s %s %s", method, uri, version);
    printf("[%s:%u] %s %s %s\n", inet_ntoa(client_addr.sin_addr),
           ntohs(client_addr.sin_port), method, version, uri);
    /*
            if (i == 0) {
            char resp[] = "HTTP/1.1 200 OK\r\n"
                      //"Server: webserver-c\r\n"
                      // "Cache-Control: no-store\r\n"
                      "Access-Control-Allow-Origin: *\r\n"
                      // "Content-type: text/event-stream\r\n"
                      "Access-Control-Allow-Headers: cache-control\r\n"
                      "Access-Control-Allow-Private-Network: true\r\n"
                      "Access-Control-Allow-Credentials: true\r\n\r\n";
                     //  "data: [1,2,3]\n\n";
            // Write to the socket
            int valwrite1 = write(newsockfd, resp, strlen(resp));
            if (valwrite1 < 0) {
                perror("webserver (write)");
                continue;
            }
            ++i;
            }
    */
    char response[] =
        "HTTP/1.1 200 OK\r\n"
        "Server: webserver-c\r\n"
        "Cache-Control: no-store\r\n"
        "Access-Control-Allow-Origin: *\r\n"
        "Content-type: application/octet-stream\r\n"
        "Access-Control-Allow-Private-Network: true\r\n\r\n";
    //  "[1,2,3]";
    // Write to the socket
    int valwrite = write(newsockfd, response, strlen(response));
    if (valwrite < 0) {
      perror("webserver (write)");
      continue;
    }
  uint8_t buffer[1764]; // 441 * 4
  char *output = malloc((1764 * 4) + 3);
  FILE *pipe = popen("parec -d @DEFAULT_MONITOR@", "r");
  //free(message);

  while (1) {
    size_t count = fread(buffer, 1, sizeof(buffer), pipe);

    output[0] = '[';
    output[1] = 0;
    for (size_t i = 0; i < count; i++) {
      char data[5];
      sprintf(data, "%d", buffer[i]);
      strcat(output, data);
      if (i < count - 1) {
        strcat(output, ",");
      }
    }
    strcat(output, "]");
    int valwrite1 = write(newsockfd, output, strlen(output));
    printf("write len : %d\n",valwrite1);
    if (valwrite1 < 0) {
      printf("webserver (write) failed ");
      continue;
    }
  }

/*
    for (int i = 0; i < 60; ++i) {
      // sleep(1);
      char str[2];
      sprintf(str, "%d", i);
      write(newsockfd, str, strlen(str));
      printf("Server UPDATE %d sent.\n", i);
    }
*/
    close(newsockfd);
  }

  return 0;
}