1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2019, 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.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 /* <DESC>
23  * Gets a file using an SFTP URL.
24  * </DESC>
25  */
26 
27 #include <stdio.h>
28 
29 #include <curl/curl.h>
30 
31 /* define this to switch off the use of ssh-agent in this program */
32 #undef DISABLE_SSH_AGENT
33 
34 /*
35  * This is an example showing how to get a single file from an SFTP server.
36  * It delays the actual destination file creation until the first write
37  * callback so that it won't create an empty file in case the remote file
38  * doesn't exist or something else fails.
39  */
40 
41 struct FtpFile {
42   const char *filename;
43   FILE *stream;
44 };
45 
my_fwrite(void * buffer,size_t size,size_t nmemb,void * stream)46 static size_t my_fwrite(void *buffer, size_t size, size_t nmemb,
47                         void *stream)
48 {
49   struct FtpFile *out = (struct FtpFile *)stream;
50   if(!out->stream) {
51     /* open file for writing */
52     out->stream = fopen(out->filename, "wb");
53     if(!out->stream)
54       return -1; /* failure, can't open file to write */
55   }
56   return fwrite(buffer, size, nmemb, out->stream);
57 }
58 
59 
main(void)60 int main(void)
61 {
62   CURL *curl;
63   CURLcode res;
64   struct FtpFile ftpfile = {
65     "yourfile.bin", /* name to store the file as if successful */
66     NULL
67   };
68 
69   curl_global_init(CURL_GLOBAL_DEFAULT);
70 
71   curl = curl_easy_init();
72   if(curl) {
73     /*
74      * You better replace the URL with one that works!
75      */
76     curl_easy_setopt(curl, CURLOPT_URL,
77                      "sftp://user@server/home/user/file.txt");
78     /* Define our callback to get called when there's data to be written */
79     curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite);
80     /* Set a pointer to our struct to pass to the callback */
81     curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ftpfile);
82 
83 #ifndef DISABLE_SSH_AGENT
84     /* We activate ssh agent. For this to work you need
85        to have ssh-agent running (type set | grep SSH_AGENT to check) or
86        pageant on Windows (there is an icon in systray if so) */
87     curl_easy_setopt(curl, CURLOPT_SSH_AUTH_TYPES, CURLSSH_AUTH_AGENT);
88 #endif
89 
90     /* Switch on full protocol/debug output */
91     curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
92 
93     res = curl_easy_perform(curl);
94 
95     /* always cleanup */
96     curl_easy_cleanup(curl);
97 
98     if(CURLE_OK != res) {
99       /* we failed */
100       fprintf(stderr, "curl told us %d\n", res);
101     }
102   }
103 
104   if(ftpfile.stream)
105     fclose(ftpfile.stream); /* close the local file */
106 
107   curl_global_cleanup();
108 
109   return 0;
110 }
111