1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22/* Upload to FTP, resuming failed transfers
23 *
24 * Compile for MinGW like this:
25 *  gcc -Wall -pedantic -std=c99 ftpuploadwithresume.c -o ftpuploadresume.exe
26 *  -lcurl -lmsvcr70
27 *
28 * Written by Philip Bock
29 */
30
31#include <stdlib.h>
32#include <stdio.h>
33
34#include <curl/curl.h>
35
36#if defined(_MSC_VER) && (_MSC_VER < 1300)
37#  error _snscanf requires MSVC 7.0 or later.
38#endif
39
40/* The MinGW headers are missing a few Win32 function definitions,
41   you shouldn't need this if you use VC++ */
42#if defined(__MINGW32__) && !defined(__MINGW64__)
43int __cdecl _snscanf(const char * input, size_t length, const char * format, ...);
44#endif
45
46
47/* parse headers for Content-Length */
48size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb, void *stream)
49{
50  int r;
51  long len = 0;
52
53  /* _snscanf() is Win32 specific */
54  r = _snscanf(ptr, size * nmemb, "Content-Length: %ld\n", &len);
55
56  if (r) /* Microsoft: we don't read the specs */
57    *((long *) stream) = len;
58
59  return size * nmemb;
60}
61
62/* discard downloaded data */
63size_t discardfunc(void *ptr, size_t size, size_t nmemb, void *stream)
64{
65  return size * nmemb;
66}
67
68/* read data to upload */
69size_t readfunc(void *ptr, size_t size, size_t nmemb, void *stream)
70{
71  FILE *f = stream;
72  size_t n;
73
74  if (ferror(f))
75    return CURL_READFUNC_ABORT;
76
77  n = fread(ptr, size, nmemb, f) * size;
78
79  return n;
80}
81
82
83int upload(CURL *curlhandle, const char * remotepath, const char * localpath,
84           long timeout, long tries)
85{
86  FILE *f;
87  long uploaded_len = 0;
88  CURLcode r = CURLE_GOT_NOTHING;
89  int c;
90
91  f = fopen(localpath, "rb");
92  if (f == NULL) {
93    perror(NULL);
94    return 0;
95  }
96
97  curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);
98
99  curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);
100
101  if (timeout)
102    curl_easy_setopt(curlhandle, CURLOPT_FTP_RESPONSE_TIMEOUT, timeout);
103
104  curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
105  curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &uploaded_len);
106
107  curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, discardfunc);
108
109  curl_easy_setopt(curlhandle, CURLOPT_READFUNCTION, readfunc);
110  curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);
111
112  curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-"); /* disable passive mode */
113  curl_easy_setopt(curlhandle, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);
114
115  curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);
116
117  for (c = 0; (r != CURLE_OK) && (c < tries); c++) {
118    /* are we resuming? */
119    if (c) { /* yes */
120      /* determine the length of the file already written */
121
122      /*
123       * With NOBODY and NOHEADER, libcurl will issue a SIZE
124       * command, but the only way to retrieve the result is
125       * to parse the returned Content-Length header. Thus,
126       * getcontentlengthfunc(). We need discardfunc() above
127       * because HEADER will dump the headers to stdout
128       * without it.
129       */
130      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 1L);
131      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);
132
133      r = curl_easy_perform(curlhandle);
134      if (r != CURLE_OK)
135        continue;
136
137      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 0L);
138      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);
139
140      fseek(f, uploaded_len, SEEK_SET);
141
142      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 1L);
143    }
144    else { /* no */
145      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 0L);
146    }
147
148    r = curl_easy_perform(curlhandle);
149  }
150
151  fclose(f);
152
153  if (r == CURLE_OK)
154    return 1;
155  else {
156    fprintf(stderr, "%s\n", curl_easy_strerror(r));
157    return 0;
158  }
159}
160
161int main(int c, char **argv)
162{
163  CURL *curlhandle = NULL;
164
165  curl_global_init(CURL_GLOBAL_ALL);
166  curlhandle = curl_easy_init();
167
168  upload(curlhandle, "ftp://user:pass@example.com/path/file", "C:\\file", 0, 3);
169
170  curl_easy_cleanup(curlhandle);
171  curl_global_cleanup();
172
173  return 0;
174}
175