summaryrefslogtreecommitdiff
path: root/docs/examples/ftpuploadresume.c
blob: d20c4a9c6afbeb31ddc42e1462e9db346132777f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id$
 *
 * Upload to FTP, resuming failed transfers
 *
 * Compile for MinGW like this:
 *  gcc -Wall -pedantic -std=c99 ftpuploadwithresume.c -o ftpuploadresume.exe
 *  -lcurl -lmsvcr70
 *
 * Written by Philip Bock
 */

#include <stdlib.h>
#include <stdio.h>

#include <curl/curl.h>

#if defined(_MSC_VER) && (_MSC_VER < 1300)
#  error _snscanf requires MSVC 7.0 or later.
#endif

/* The MinGW headers are missing a few Win32 function definitions,
   you shouldn't need this if you use VC++ */
#ifdef __MINGW32__
int __cdecl _snscanf(const char * input, size_t length, const char * format, ...);
#endif


/* parse headers for Content-Length */
size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb, void *stream) {
  int r;
  long len = 0;

  /* _snscanf() is Win32 specific */
  r = _snscanf(ptr, size * nmemb, "Content-Length: %ld\n", &len);

  if (r) /* Microsoft: we don't read the specs */
    *((long *) stream) = len;

  return size * nmemb;
}

/* discard downloaded data */
size_t discardfunc(void *ptr, size_t size, size_t nmemb, void *stream) {
  return size * nmemb;
}

/* read data to upload */
size_t readfunc(void *ptr, size_t size, size_t nmemb, void *stream)
{
  FILE *f = stream;
  size_t n;

  if (ferror(f))
    return CURL_READFUNC_ABORT;

  n = fread(ptr, size, nmemb, f) * size;

  return n;
}


int upload(CURL *curlhandle, const char * remotepath, const char * localpath,
           long timeout, long tries)
{
  FILE *f;
  long uploaded_len = 0;
  CURLcode r = CURLE_GOT_NOTHING;
  int c;

  f = fopen(localpath, "rb");
  if (f == NULL) {
    perror(NULL);
    return 0;
  }

  curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);

  curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);

  if (timeout)
    curl_easy_setopt(curlhandle, CURLOPT_FTP_RESPONSE_TIMEOUT, timeout);

  curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
  curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &uploaded_len);

  curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, discardfunc);

  curl_easy_setopt(curlhandle, CURLOPT_READFUNCTION, readfunc);
  curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);

  curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-"); /* disable passive mode */
  curl_easy_setopt(curlhandle, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);

  curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);

  for (c = 0; (r != CURLE_OK) && (c < tries); c++) {
    /* are we resuming? */
    if (c) { /* yes */
      /* determine the length of the file already written */

      /*
       * With NOBODY and NOHEADER, libcurl will issue a SIZE
       * command, but the only way to retrieve the result is
       * to parse the returned Content-Length header. Thus,
       * getcontentlengthfunc(). We need discardfunc() above
       * because HEADER will dump the headers to stdout
       * without it.
       */
      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 1L);
      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);

      r = curl_easy_perform(curlhandle);
      if (r != CURLE_OK)
        continue;

      curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 0L);
      curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);

      fseek(f, uploaded_len, SEEK_SET);

      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 1L);
    }
    else { /* no */
      curl_easy_setopt(curlhandle, CURLOPT_APPEND, 0L);
    }

    r = curl_easy_perform(curlhandle);
  }

  fclose(f);

  if (r == CURLE_OK)
    return 1;
  else {
    fprintf(stderr, "%s\n", curl_easy_strerror(r));
    return 0;
  }
}

int main(int c, char **argv) {
  CURL *curlhandle = NULL;

  curl_global_init(CURL_GLOBAL_ALL);
  curlhandle = curl_easy_init();

  upload(curlhandle, "ftp://user:pass@host/path/file", "C:\\file", 0, 3);

  curl_easy_cleanup(curlhandle);
  curl_global_cleanup();

  return 0;
}