We actively encourage users to first try out the transfer they want to do with
the curl command-line tool, and once it works roughly the way you want it to,
you append the --libcurl [filename]
option to the command line and run it
again.
The --libcurl
command-line option creates a C program in the provided file
name. That C program is an application that uses libcurl to run the transfer
you just had the curl command-line tool do. There are some exceptions and it
is not always a 100% match, but you might find that it can serve as an
excellent inspiration source for what libcurl options you want or can use and
what additional arguments to provide to them.
If you specify the filename as a single dash, as in --libcurl -
you get the
program written to stdout instead of a file.
As an example, we run a command to get http://example.com
:
curl http://example.com --libcurl example.c
This creates example.c
in the current directory, looking similar to this:
/********* Sample code generated by the curl command-line tool **********
* All curl_easy_setopt() options are documented at:
* https://curl.se/libcurl/c/curl_easy_setopt.html
************************************************************************/
#include <curl/curl.h>
int main(int argc, char *argv[])
{
CURLcode ret;
CURL *hnd;
hnd = curl_easy_init();
curl_easy_setopt(hnd, CURLOPT_URL, "http://example.com");
curl_easy_setopt(hnd, CURLOPT_NOPROGRESS, 1L);
curl_easy_setopt(hnd, CURLOPT_USERAGENT, "curl/7.45.0");
curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
curl_easy_setopt(hnd, CURLOPT_SSH_KNOWNHOSTS,
"/home/daniel/.ssh/known_hosts");
curl_easy_setopt(hnd, CURLOPT_TCP_KEEPALIVE, 1L);
/* Here is a list of options the curl code used that cannot get
generated as source easily. You may select to either not use them or
implement them yourself.
CURLOPT_WRITEDATA set to a objectpointer
CURLOPT_WRITEFUNCTION set to a functionpointer
CURLOPT_READDATA set to a objectpointer
CURLOPT_READFUNCTION set to a functionpointer
CURLOPT_SEEKDATA set to a objectpointer
CURLOPT_SEEKFUNCTION set to a functionpointer
CURLOPT_ERRORBUFFER set to a objectpointer
CURLOPT_STDERR set to a objectpointer
CURLOPT_HEADERFUNCTION set to a functionpointer
CURLOPT_HEADERDATA set to a objectpointer
*/
ret = curl_easy_perform(hnd);
curl_easy_cleanup(hnd);
hnd = NULL;
return (int)ret;
}
/**** End of sample code ****/