ftpupload.c
/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * 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 * ***************************************************************************/ #include <stdio.h> #include <string.h> #include <curl/curl.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h> #ifdef _WIN32 #include <io.h> #undef stat #define stat _stat #else #include <unistd.h> #endif /* <DESC> * Performs an FTP upload and renames the file just after a successful * transfer. * </DESC> */ #define LOCAL_FILE "/tmp/uploadthis.txt" #define UPLOAD_FILE_AS "while-uploading.txt" #define REMOTE_URL "ftp://example.com/" UPLOAD_FILE_AS #define RENAME_FILE_TO "renamed-and-fine.txt" /* NOTE: if you want this example to work on Windows with libcurl as a DLL, you MUST also provide a read callback with CURLOPT_READFUNCTION. Failing to do so might give you a crash since a DLL may not use the variable's memory when passed in to it from an app like this. */ static size_t read_callback(char *ptr, size_t size, size_t nmemb, void *stream) { unsigned long nread; /* in real-world cases, this would probably get this data differently as this fread() stuff is exactly what the library already would do by default internally */ size_t retcode = fread(ptr, size, nmemb, stream); if(retcode > 0) { nread = (unsigned long)retcode; fprintf(stderr, "*** We read %lu bytes from file\n", nread); } return retcode; } int main(void) { CURL *curl; CURLcode res; FILE *hd_src; struct stat file_info; unsigned long fsize; struct curl_slist *headerlist = NULL; static const char buf_1 [] = "RNFR " UPLOAD_FILE_AS; static const char buf_2 [] = "RNTO " RENAME_FILE_TO; /* get the file size of the local file */ if(stat(LOCAL_FILE, &file_info)) { printf("Couldn't open '%s': %s\n", LOCAL_FILE, strerror(errno)); return 1; } fsize = (unsigned long)file_info.st_size; printf("Local file size: %lu bytes.\n", fsize); /* get a FILE * of the same file */ hd_src = fopen(LOCAL_FILE, "rb"); /* In Windows, this inits the Winsock stuff */ curl_global_init(CURL_GLOBAL_ALL); /* get a curl handle */ curl = curl_easy_init(); if(curl) { /* build a list of commands to pass to libcurl */ headerlist = curl_slist_append(headerlist, buf_1); headerlist = curl_slist_append(headerlist, buf_2); /* we want to use our own read function */ curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback); /* enable uploading */ curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L); /* specify target */ curl_easy_setopt(curl, CURLOPT_URL, REMOTE_URL); /* pass in that last of FTP commands to run after the transfer */ curl_easy_setopt(curl, CURLOPT_POSTQUOTE, headerlist); /* now specify which file to upload */ curl_easy_setopt(curl, CURLOPT_READDATA, hd_src); /* Set the size of the file to upload (optional). If you give a *_LARGE option you MUST make sure that the type of the passed-in argument is a curl_off_t. If you use CURLOPT_INFILESIZE (without _LARGE) you must make sure that to pass in a type 'long' argument. */ curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, (curl_off_t)fsize); /* Now run off and do what you have been told! */ res = curl_easy_perform(curl); /* Check for errors */ if(res != CURLE_OK) fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res)); /* clean up the FTP commands list */ curl_slist_free_all(headerlist); /* always cleanup */ curl_easy_cleanup(curl); } fclose(hd_src); /* close the local file */ curl_global_cleanup(); return 0; }
Notice
This source code example is simplified and ignores return
codes and error checks to a large extent. We do this to highlight the libcurl
function calls and related options and reduce unrelated code.
A real-world application will of course properly check every return value and exit correctly at the first serious error.