From 0b1197936c488950041cc54db9db9af1d82ea0b8 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Tue, 8 Jan 2002 13:05:44 +0000 Subject: I made the write callback create the file the first time it gets called so that it won't create an empty file if the remote file doesn't exist --- docs/examples/ftpget.c | 61 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 50 insertions(+), 11 deletions(-) (limited to 'docs/examples/ftpget.c') diff --git a/docs/examples/ftpget.c b/docs/examples/ftpget.c index bdf854521..6d728c6ec 100644 --- a/docs/examples/ftpget.c +++ b/docs/examples/ftpget.c @@ -14,31 +14,70 @@ #include #include -/* to make this work under windows, use the win32-functions from the - win32socket.c file as well */ +/* + * This is an example showing how to get a single file from an FTP server. + * It delays the actual destination file creation until the first write + * callback so that it won't create an empty file in case the remote file + * doesn't exist or something else fails. + */ + +struct FtpFile { + char *filename; + FILE *stream; +}; + +int my_fwrite(void *buffer, size_t size, size_t nmemb, void *stream) +{ + struct FtpFile *out=(struct FtpFile *)stream; + if(out && !out->stream) { + /* open file for writing */ + out->stream=fopen(out->filename, "wb"); + if(!out->stream) + return -1; /* failure, can't open file to write */ + } + return fwrite(buffer, size, nmemb, out->stream); +} + -int main(int argc, char **argv) +int main(void) { CURL *curl; CURLcode res; - FILE *ftpfile; - - /* local file name to store the file as */ - ftpfile = fopen("curl.tar.gz", "wb"); /* b is binary for win */ + struct FtpFile ftpfile={ + "curl.tar.gz", /* name to store the file as if succesful */ + NULL + }; + curl_global_init(CURL_GLOBAL_DEFAULT); + curl = curl_easy_init(); if(curl) { - /* Get curl 7.7 from sunet.se's FTP site: */ + /* Get curl 7.9.2 from sunet.se's FTP site: */ curl_easy_setopt(curl, CURLOPT_URL, - "ftp://ftp.sunet.se/pub/www/utilities/curl/curl-7.7.tar.gz"); - curl_easy_setopt(curl, CURLOPT_FILE, ftpfile); + "ftp://ftp.sunet.se/pub/www/utilities/curl/curl-7.9.2.tar.gz"); + /* Define our callback to get called when there's data to be written */ + curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_fwrite); + /* Set a pointer to our struct to pass to the callback */ + curl_easy_setopt(curl, CURLOPT_FILE, &ftpfile); + + /* Switch on full protocol/debug output */ + curl_easy_setopt(curl, CURLOPT_VERBOSE, TRUE); + res = curl_easy_perform(curl); /* always cleanup */ curl_easy_cleanup(curl); + + if(CURLE_OK != res) { + /* we failed */ + fprintf(stderr, "curl told us %d\n", res); + } } - fclose(ftpfile); /* close the local file */ + if(ftpfile.stream) + fclose(ftpfile.stream); /* close the local file */ + + curl_global_cleanup(); return 0; } -- cgit v1.2.3