1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2020, 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 https://curl.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 /* <DESC>
23 * Upload to FTP, resuming failed transfers.
24 * </DESC>
25 */
26
27 #include <stdlib.h>
28 #include <stdio.h>
29 #include <curl/curl.h>
30
31 /* parse headers for Content-Length */
getcontentlengthfunc(void * ptr,size_t size,size_t nmemb,void * stream)32 static size_t getcontentlengthfunc(void *ptr, size_t size, size_t nmemb,
33 void *stream)
34 {
35 int r;
36 long len = 0;
37
38 r = sscanf(ptr, "Content-Length: %ld\n", &len);
39 if(r)
40 *((long *) stream) = len;
41
42 return size * nmemb;
43 }
44
45 /* discard downloaded data */
discardfunc(void * ptr,size_t size,size_t nmemb,void * stream)46 static size_t discardfunc(void *ptr, size_t size, size_t nmemb, void *stream)
47 {
48 (void)ptr;
49 (void)stream;
50 return size * nmemb;
51 }
52
53 /* read data to upload */
readfunc(char * ptr,size_t size,size_t nmemb,void * stream)54 static size_t readfunc(char *ptr, size_t size, size_t nmemb, void *stream)
55 {
56 FILE *f = stream;
57 size_t n;
58
59 if(ferror(f))
60 return CURL_READFUNC_ABORT;
61
62 n = fread(ptr, size, nmemb, f) * size;
63
64 return n;
65 }
66
67
upload(CURL * curlhandle,const char * remotepath,const char * localpath,long timeout,long tries)68 static int upload(CURL *curlhandle, const char *remotepath,
69 const char *localpath, long timeout, long tries)
70 {
71 FILE *f;
72 long uploaded_len = 0;
73 CURLcode r = CURLE_GOT_NOTHING;
74 int c;
75
76 f = fopen(localpath, "rb");
77 if(!f) {
78 perror(NULL);
79 return 0;
80 }
81
82 curl_easy_setopt(curlhandle, CURLOPT_UPLOAD, 1L);
83
84 curl_easy_setopt(curlhandle, CURLOPT_URL, remotepath);
85
86 if(timeout)
87 curl_easy_setopt(curlhandle, CURLOPT_FTP_RESPONSE_TIMEOUT, timeout);
88
89 curl_easy_setopt(curlhandle, CURLOPT_HEADERFUNCTION, getcontentlengthfunc);
90 curl_easy_setopt(curlhandle, CURLOPT_HEADERDATA, &uploaded_len);
91
92 curl_easy_setopt(curlhandle, CURLOPT_WRITEFUNCTION, discardfunc);
93
94 curl_easy_setopt(curlhandle, CURLOPT_READFUNCTION, readfunc);
95 curl_easy_setopt(curlhandle, CURLOPT_READDATA, f);
96
97 /* disable passive mode */
98 curl_easy_setopt(curlhandle, CURLOPT_FTPPORT, "-");
99 curl_easy_setopt(curlhandle, CURLOPT_FTP_CREATE_MISSING_DIRS, 1L);
100
101 curl_easy_setopt(curlhandle, CURLOPT_VERBOSE, 1L);
102
103 for(c = 0; (r != CURLE_OK) && (c < tries); c++) {
104 /* are we resuming? */
105 if(c) { /* yes */
106 /* determine the length of the file already written */
107
108 /*
109 * With NOBODY and NOHEADER, libcurl will issue a SIZE
110 * command, but the only way to retrieve the result is
111 * to parse the returned Content-Length header. Thus,
112 * getcontentlengthfunc(). We need discardfunc() above
113 * because HEADER will dump the headers to stdout
114 * without it.
115 */
116 curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 1L);
117 curl_easy_setopt(curlhandle, CURLOPT_HEADER, 1L);
118
119 r = curl_easy_perform(curlhandle);
120 if(r != CURLE_OK)
121 continue;
122
123 curl_easy_setopt(curlhandle, CURLOPT_NOBODY, 0L);
124 curl_easy_setopt(curlhandle, CURLOPT_HEADER, 0L);
125
126 fseek(f, uploaded_len, SEEK_SET);
127
128 curl_easy_setopt(curlhandle, CURLOPT_APPEND, 1L);
129 }
130 else { /* no */
131 curl_easy_setopt(curlhandle, CURLOPT_APPEND, 0L);
132 }
133
134 r = curl_easy_perform(curlhandle);
135 }
136
137 fclose(f);
138
139 if(r == CURLE_OK)
140 return 1;
141 else {
142 fprintf(stderr, "%s\n", curl_easy_strerror(r));
143 return 0;
144 }
145 }
146
main(void)147 int main(void)
148 {
149 CURL *curlhandle = NULL;
150
151 curl_global_init(CURL_GLOBAL_ALL);
152 curlhandle = curl_easy_init();
153
154 upload(curlhandle, "ftp://user:pass@example.com/path/file", "C:\\file",
155 0, 3);
156
157 curl_easy_cleanup(curlhandle);
158 curl_global_cleanup();
159
160 return 0;
161 }
162