githubmirror/libmicrohttpd

doc/examples/responseheaders.c
102 строки3 KB
Christian Grothoff
add tutorials for #4944 and #5085
28 июл 2026, 20:46
28 июл 2026, 20:467d8c068
/* Feel free to use this example code in any way
   you see fit (Public Domain) */

#include <sys/types.h>
#ifndef _WIN32
#include <sys/select.h>
#include <sys/socket.h>
#else
#include <winsock2.h>
#endif
#include <microhttpd.h>
#include <time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>

#define PORT 8888
#define FILENAME "picture.png"
#define MIMETYPE "image/png"

static enum MHD_Result
answer_to_connection (void *cls, struct MHD_Connection *connection,
                      const char *url, const char *method,
                      const char *version, const char *upload_data,
                      size_t *upload_data_size, void **req_cls)
{
  struct MHD_Response *response;
  int fd;
  enum MHD_Result ret;
  struct stat sbuf;
  (void) cls;               /* Unused. Silent compiler warning. */
  (void) url;               /* Unused. Silent compiler warning. */
  (void) version;           /* Unused. Silent compiler warning. */
  (void) upload_data;       /* Unused. Silent compiler warning. */
  (void) upload_data_size;  /* Unused. Silent compiler warning. */
  (void) req_cls;           /* Unused. Silent compiler warning. */

  if (0 != strcmp (method, "GET"))
    return MHD_NO;

  if ( (-1 == (fd = open (FILENAME, O_RDONLY))) ||
       (0 != fstat (fd, &sbuf)) )
  {
    const char *errorstr =
      "<html><body>An internal server error has occurred!\
                              </body></html>";
    /* error accessing file */
    if (fd != -1)
      (void) close (fd);
    response =
      MHD_create_response_from_buffer_static (strlen (errorstr), errorstr);
    if (NULL != response)
    {
      ret =
        MHD_queue_response (connection, MHD_HTTP_INTERNAL_SERVER_ERROR,
                            response);
      MHD_destroy_response (response);

      return ret;
    }
    else
      return MHD_NO;
  }
  response =
    MHD_create_response_from_fd_at_offset64 ((uint64_t) sbuf.st_size,
                                             fd,
                                             0);
  if (MHD_YES !=
      MHD_add_response_header (response,
                               MHD_HTTP_HEADER_CONTENT_TYPE,
                               MIMETYPE))
  {
    fprintf (stderr,
             "Failed to set content type header!\n");
    /* return response without content encoding anyway ... */
  }
  ret = MHD_queue_response (connection,
                            MHD_HTTP_OK,
                            response);
  MHD_destroy_response (response);

  return ret;
}


int
main (void)
{
  struct MHD_Daemon *daemon;

  daemon = MHD_start_daemon (MHD_USE_INTERNAL_POLLING_THREAD, PORT, NULL, NULL,
                             &answer_to_connection, NULL, MHD_OPTION_END);
  if (NULL == daemon)
    return 1;

  (void) getchar ();

  MHD_stop_daemon (daemon);

  return 0;
}