curl / libcurl / API / Examples / ftp-wildcard.c

ftp-wildcard.c

/***************************************************************************
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 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
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 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
/* <DESC>
 * FTP wildcard pattern matching
 * </DESC>
 */
#ifdef _MSC_VER
#ifndef _CRT_SECURE_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS  /* for fopen() */
#endif
#endif
 
#include <stdio.h>
 
#include <curl/curl.h>
 
struct callback_data {
  FILE *output;
};
 
static long file_is_coming(struct curl_fileinfo *finfo, void *input,
                           int remains)
{
  struct callback_data *data = input;
  printf("%3d %40s %10luB ", remains, finfo->filename,
         (unsigned long)finfo->size);
 
  switch(finfo->filetype) {
  case CURLFILETYPE_DIRECTORY:
    printf(" DIR\n");
    break;
  case CURLFILETYPE_FILE:
    printf("FILE ");
    break;
  default:
    printf("OTHER\n");
    break;
  }
 
  if(finfo->filetype == CURLFILETYPE_FILE) {
    /* do not transfer files >= 50B */
    if(finfo->size > 50) {
      printf("SKIPPED\n");
      return CURL_CHUNK_BGN_FUNC_SKIP;
    }
 
    data->output = fopen(finfo->filename, "wb");
    if(!data->output) {
      return CURL_CHUNK_BGN_FUNC_FAIL;
    }
  }
 
  return CURL_CHUNK_BGN_FUNC_OK;
}
 
static long file_is_downloaded(void *input)
{
  struct callback_data *data = input;
  if(data->output) {
    printf("DOWNLOADED\n");
    fclose(data->output);
    data->output = 0x0;
  }
  return CURL_CHUNK_END_FUNC_OK;
}
 
static size_t write_cb(char *buff, size_t size, size_t nmemb, void *cb_data)
{
  struct callback_data *data = cb_data;
  size_t written = 0;
  if(data->output)
    written = fwrite(buff, size, nmemb, data->output);
  else
    /* listing output */
    written = fwrite(buff, size, nmemb, stdout);
  return written;
}
 
int main(int argc, const char **argv)
{
  /* curl easy handle */
  CURL *curl;
 
  /* help data */
  struct callback_data data = { 0 };
 
  /* global initialization */
  CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
  if(result != CURLE_OK)
    return (int)result;
 
  /* initialization of easy handle */
  curl = curl_easy_init();
  if(!curl) {
    curl_global_cleanup();
    return CURLE_OUT_OF_MEMORY;
  }
 
  /* turn on wildcard matching */
  curl_easy_setopt(curl, CURLOPT_WILDCARDMATCH, 1L);
 
  /* callback is called before download of concrete file started */
  curl_easy_setopt(curl, CURLOPT_CHUNK_BGN_FUNCTION, file_is_coming);
 
  /* callback is called after data from the file have been transferred */
  curl_easy_setopt(curl, CURLOPT_CHUNK_END_FUNCTION, file_is_downloaded);
 
  /* this callback writes contents into files */
  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_cb);
 
  /* put transfer data into callbacks */
  curl_easy_setopt(curl, CURLOPT_CHUNK_DATA, &data);
  curl_easy_setopt(curl, CURLOPT_WRITEDATA, &data);
 
#if 0
  curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
#endif
 
  /* set a URL containing wildcard pattern (only in the last part) */
  if(argc == 2)
    curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
  else
    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/test/*");
 
  /* and start transfer! */
  result = curl_easy_perform(curl);
 
  curl_easy_cleanup(curl);
  curl_global_cleanup();
  return (int)result;
}

Notice

This source code example is simplified and may ignore return codes and error checks. We do this to highlight the libcurl function calls and related options and reduce unrelated code.

A real-world application does of course properly check every return value and exit correctly at the first serious error.