githubmirror/libmicrohttpd

doc/examples/simplepost.c
219 строк6 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 <stdio.h>
#include <string.h>
#include <stdlib.h>

#if defined(_MSC_VER) && _MSC_VER + 0 <= 1800
/* Substitution is OK while return value is not used */
#define snprintf _snprintf
#endif

#define PORT            8888
#define POSTBUFFERSIZE  512
#define MAXNAMESIZE     20
#define MAXANSWERSIZE   512

struct connection_info_struct
{
  enum { GET, POST } connectiontype;
  char *answerstring;
  struct MHD_PostProcessor *postprocessor;
};

static const char *askpage =
  "<html><body>\n"
  "What's your name, Sir?<br>\n"
  "<form action=\"/namepost\" method=\"post\">\n"
  "<input name=\"name\" type=\"text\">\n"
  "<input type=\"submit\" value=\" Send \"></form>\n"
  "</body></html>";

#define GREETINGPAGE \
        "<html><body><h1>Welcome, %s!</h1></body></html>"

static const char *errorpage =
  "<html><body>This doesn't seem to be right.</body></html>";


static enum MHD_Result
send_page (struct MHD_Connection *connection,
           const char *page)
{
  enum MHD_Result ret;
  struct MHD_Response *response;

  response = MHD_create_response_from_buffer_static (strlen (page),
                                                     page);
  if (! response)
    return MHD_NO;
  ret = MHD_queue_response (connection,
                            MHD_HTTP_OK,
                            response);
  MHD_destroy_response (response);
  return ret;
}


static enum MHD_Result
iterate_post (void *coninfo_cls,
              enum MHD_ValueKind kind,
              const char *key,
              const char *filename,
              const char *content_type,
              const char *transfer_encoding,
              const char *data,
              uint64_t off,
              size_t size)
{
  struct connection_info_struct *con_info = coninfo_cls;

  (void) kind;               /* Unused. Silent compiler warning. */
  (void) filename;           /* Unused. Silent compiler warning. */
  (void) content_type;       /* Unused. Silent compiler warning. */
  (void) transfer_encoding;  /* Unused. Silent compiler warning. */
  (void) off;                /* Unused. Silent compiler warning. */
  if (0 != strcmp (key,
                   "name"))
    return MHD_YES;
  if ( (size > 0) &&
       (size <= MAXNAMESIZE) )
  {
    char *answerstring;

    answerstring = malloc (MAXANSWERSIZE);
    if (! answerstring)
      return MHD_NO;
    snprintf (answerstring,
              MAXANSWERSIZE,
              GREETINGPAGE,
              data);
    con_info->answerstring = answerstring;
  }
  else
  {
    con_info->answerstring = NULL;
  }
  return MHD_YES;
}


static void
request_completed (void *cls,
                   struct MHD_Connection *connection,
                   void **req_cls,
                   enum MHD_RequestTerminationCode toe)
{
  struct connection_info_struct *con_info = *req_cls;

  (void) cls;         /* Unused. Silent compiler warning. */
  (void) connection;  /* Unused. Silent compiler warning. */
  (void) toe;         /* Unused. Silent compiler warning. */
  if (NULL == con_info)
    return;
  if (POST == con_info->connectiontype)
  {
    MHD_destroy_post_processor (con_info->postprocessor);
    if (con_info->answerstring)
      free (con_info->answerstring);
  }
  free (con_info);
  *req_cls = NULL;
}


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 connection_info_struct *con_info = *req_cls;

  (void) cls;               /* Unused. Silent compiler warning. */
  (void) url;               /* Unused. Silent compiler warning. */
  (void) version;           /* Unused. Silent compiler warning. */
  if (NULL == con_info)
  {
    con_info = malloc (sizeof (struct connection_info_struct));
    *req_cls = (void *) con_info;
    if (NULL == con_info)
      return MHD_NO;
    con_info->answerstring = NULL;

    if (0 == strcmp (method, "POST"))
    {
      con_info->postprocessor =
        MHD_create_post_processor (connection,
                                   POSTBUFFERSIZE,
                                   iterate_post,
                                   (void *) con_info);
      if (NULL == con_info->postprocessor)
      {
        free (con_info);
        return MHD_NO;
      }
      con_info->connectiontype = POST;
    }
    else
    {
      con_info->connectiontype = GET;
    }
    return MHD_YES;
  }
  if (0 == strcmp (method, "GET"))
  {
    return send_page (connection,
                      askpage);
  }
  if (0 == strcmp (method, "POST"))
  {
    if (0 != *upload_data_size)
    {
      if (MHD_YES !=
          MHD_post_process (con_info->postprocessor,
                            upload_data,
                            *upload_data_size))
        return MHD_NO;
      *upload_data_size = 0;
      return MHD_YES;
    }
    else if (NULL != con_info->answerstring)
      return send_page (connection,
                        con_info->answerstring);
  }
  return send_page (connection,
                    errorpage);
}


int
main (void)
{
  struct MHD_Daemon *daemon;

  daemon = MHD_start_daemon (MHD_USE_AUTO | MHD_USE_INTERNAL_POLLING_THREAD,
                             PORT, NULL, NULL,
                             &answer_to_connection, NULL,
                             MHD_OPTION_NOTIFY_COMPLETED,
                             &request_completed, NULL,
                             MHD_OPTION_END);
  if (NULL == daemon)
    return 1;
  (void) getchar ();
  MHD_stop_daemon (daemon);
  return 0;
}