libmicrohttpd/doc/examples/responseheaders.c

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

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


long GetFileSize(const char *filename)
{
  FILE *fp;
  
  fp = fopen(filename, "rb");
  if (fp) 
  {
    long size;

    if ( (0!=fseek(fp, 0, SEEK_END)) || (-1==(size=ftell(fp))) )
      size = 0;
   
    fclose(fp);
    return size;
  } else return 0;
}


int AnswerToConnection(void *cls, struct MHD_Connection *connection, const char *url, 
    const char *method, const char *version, const char *upload_data, 
    unsigned int *upload_data_size, void **con_cls)
{
  unsigned char *buffer;
  struct MHD_Response *response;
  long size;
  FILE *fp;
  int ret=0;

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

  size = GetFileSize(FILENAME);
  if (size != 0)
  {
    fp = fopen(FILENAME, "rb");
    if (fp) 
    {
      buffer = malloc(size);
      if (buffer)
        if (size == fread(buffer, 1, size, fp)) ret=1;
    }  
      
    fclose(fp);
  }

  if (!ret) 
  {
    const char *errorstr = "<html><body>An internal server error has occured!\
                            </body></html>";

    if (buffer) free(buffer);
    response = MHD_create_response_from_data(strlen(errorstr), (void*)errorstr,
                                             MHD_NO, MHD_NO);

    ret = MHD_queue_response (connection, MHD_HTTP_INTERNAL_SERVER_ERROR, response);
    MHD_destroy_response (response);
    return MHD_YES;    
  }

  response = MHD_create_response_from_data(size, (void*)buffer, MHD_YES, MHD_NO);

  MHD_add_response_header(response, "Content-Type", MIMETYPE);

  ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
  MHD_destroy_response (response);
  return ret;
}


int main ()
{
  struct MHD_Daemon *daemon;

  daemon = MHD_start_daemon(MHD_USE_SELECT_INTERNALLY, PORT, NULL, NULL, 
                            &AnswerToConnection, NULL, MHD_OPTION_END);

  if (daemon == NULL) return 1;

  getchar(); 

  MHD_stop_daemon(daemon);
  return 0;
}