added more text in the 'passwords' section

 Repeated calls to curl_global_init() and curl_global_cleanup() should be

 avoided. They should be called once each.

Handle the easy libcurl

Handle the Easy libcurl

 libcurl version 7 is oriented around the so called easy interface. All

 operations in the easy interface are prefixed with 'curl_easy'.

 the custom pointer libcurl will pass to our read callback. The read callback

 should have a prototype similar to:

   size_t function(char *buffer, size_t size, size_t nitems, void *userp);

    size_t function(char *bufptr, size_t size, size_t nitems, void *userp);

 Where buffer is the pointer to a buffer we fill in with data to upload and

 size*nitems is the size of the buffer. The 'userp' pointer is the custom

 pointer we set to point to a struct of ours to pass private data between the

 application and the callback.

 Where bufptr is the pointer to a buffer we fill in with data to upload and

 size*nitems is the size of the buffer and therefore also the maximum amount

 of data we can return to libcurl in this call. The 'userp' pointer is the

 custom pointer we set to point to a struct of ours to pass private data

 between the application and the callback.

    curl_easy_setopt(easyhandle, CURLOPT_READFUNCTION, read_function);

    curl_easy_setopt(easyhandle, CURLOPT_INFILESIZE, file_size);

 So, then you call curl_easy_perform() this time, it'll perform all necessary

 When you call curl_easy_perform() this time, it'll perform all the necessary

 operations and when it has invoked the upload it'll call your supplied

 callback to get the data to upload. The program should return as much data as

 possible in every invoke, as that is likely to make the upload perform as

 to be able to download or upload the data of your choice. libcurl offers

 several ways to specify them.

  [ URL, options, callback ]

 Most protocols support that you specify the name and password in the URL

 itself. libcurl will detect this and use them accordingly. This is written

 like this:

        protocol://user:password@example.com/path/

 If you need any odd letters in your user name or password, you should enter

 them URL encoded, as %XX where XX is a two-digit hexadecimal number.

 libcurl also provides options to set various passwords. The user name and

 password as shown embedded in the URL can instead get set with the

 CURLOPT_USERPWD option. The argument passed to libcurl should be a char * to

 a string in the format "user:password:". In a manner like this:

        curl_easy_setopt(easyhandle, CURLOPT_USERPWD, "myname:thesecret");

 Another case where name and password might be needed at times, is for those

 users who need to athenticate themselves to a proxy they use. libcurl offers

 another option for this, the CURLOPT_PROXYUSERPWD. It is used quite similar

 to the CURLOPT_USERPWD option like this:

        curl_easy_setopt(easyhandle, CURLOPT_PROXYUSERPWD, "myname:thesecret");

  [ more options, setting passsword callback ]

Showing Progress