post-callback.c
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上传日期:2018-10-23
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- /*****************************************************************************
- * _ _ ____ _
- * Project ___| | | | _ | |
- * / __| | | | |_) | |
- * | (__| |_| | _ <| |___
- * ___|___/|_| ______|
- *
- * $Id: post-callback.c,v 1.10 2008-05-22 21:20:09 danf Exp $
- *
- * An example source code that issues a HTTP POST and we provide the actual
- * data through a read callback.
- *
- */
- #include <stdio.h>
- #include <string.h>
- #include <curl/curl.h>
- const char data[]="this is what we post to the silly web server";
- struct WriteThis {
- const char *readptr;
- int sizeleft;
- };
- static size_t read_callback(void *ptr, size_t size, size_t nmemb, void *userp)
- {
- struct WriteThis *pooh = (struct WriteThis *)userp;
- if(size*nmemb < 1)
- return 0;
- if(pooh->sizeleft) {
- *(char *)ptr = pooh->readptr[0]; /* copy one single byte */
- pooh->readptr++; /* advance pointer */
- pooh->sizeleft--; /* less data left */
- return 1; /* we return 1 byte at a time! */
- }
- return 0; /* no more data left to deliver */
- }
- int main(void)
- {
- CURL *curl;
- CURLcode res;
- struct WriteThis pooh;
- pooh.readptr = data;
- pooh.sizeleft = strlen(data);
- curl = curl_easy_init();
- if(curl) {
- /* First set the URL that is about to receive our POST. */
- curl_easy_setopt(curl, CURLOPT_URL,
- "http://receivingsite.com.pooh/index.cgi");
- /* Now specify we want to POST data */
- curl_easy_setopt(curl, CURLOPT_POST, 1L);
- /* we want to use our own read function */
- curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);
- /* pointer to pass to our read function */
- curl_easy_setopt(curl, CURLOPT_READDATA, &pooh);
- /* get verbose debug output please */
- curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
- /*
- If you use POST to a HTTP 1.1 server, you can send data without knowing
- the size before starting the POST if you use chunked encoding. You
- enable this by adding a header like "Transfer-Encoding: chunked" with
- CURLOPT_HTTPHEADER. With HTTP 1.0 or without chunked transfer, you must
- specify the size in the request.
- */
- #ifdef USE_CHUNKED
- {
- struct curl_slist *chunk = NULL;
- chunk = curl_slist_append(chunk, "Transfer-Encoding: chunked");
- res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
- /* use curl_slist_free_all() after the *perform() call to free this
- list again */
- }
- #else
- /* Set the expected POST size. If you want to POST large amounts of data,
- consider CURLOPT_POSTFIELDSIZE_LARGE */
- curl_easy_setopt(curl, CURLOPT_POSTFIELDSIZE, (curl_off_t)pooh.sizeleft);
- #endif
- #ifdef DISABLE_EXPECT
- /*
- Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue"
- header. You can disable this header with CURLOPT_HTTPHEADER as usual.
- NOTE: if you want chunked transfer too, you need to combine these two
- since you can only set one list of headers with CURLOPT_HTTPHEADER. */
- /* A less good option would be to enforce HTTP 1.0, but that might also
- have other implications. */
- {
- struct curl_slist *chunk = NULL;
- chunk = curl_slist_append(chunk, "Expect:");
- res = curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
- /* use curl_slist_free_all() after the *perform() call to free this
- list again */
- }
- #endif
- /* Perform the request, res will get the return code */
- res = curl_easy_perform(curl);
- /* always cleanup */
- curl_easy_cleanup(curl);
- }
- return 0;
- }