.\" * | (__| |_| | _ <| |___
.\" * \___|\___/|_| \_\_____|
.\" *
-.\" * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2015, 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 http://curl.haxx.se/docs/copyright.html.
+.\" * are also available at https://curl.haxx.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
application, so you must make sure it remains until curl no longer needs it.
If the data isn't NUL-terminated, or if you'd like it to contain zero bytes,
you must set its length with \fBCURLFORM_CONTENTSLENGTH\fP.
+.IP CURLFORM_CONTENTLEN
+followed by a curl_off_t value giving the length of the contents. Note that
+for \fICURLFORM_STREAM\fP contents, this option is mandatory.
+
+If you pass a 0 (zero) for this option, libcurl will instead do a strlen() on
+the contents to figure out the size. If you really want to send a zero byte
+content then you must make sure strlen() on the data pointer returns zero.
+
+(Option added in 7.46.0)
.IP CURLFORM_CONTENTSLENGTH
+(This option is deprecated. Use \fICURLFORM_CONTENTLEN\fP instead!)
+
followed by a long giving the length of the contents. Note that for
\fICURLFORM_STREAM\fP contents, this option is mandatory.
providing multiple \fBCURLFORM_FILE\fP arguments each followed by the filename
(and each \fICURLFORM_FILE\fP is allowed to have a
\fICURLFORM_CONTENTTYPE\fP).
+
+The given upload file has to exist in its full in the file system already when
+the upload starts, as libcurl needs to read the correct file size beforehand.
.IP CURLFORM_CONTENTTYPE
is used in combination with \fICURLFORM_FILE\fP. Followed by a pointer to a
string which provides the content-type for this part, possibly instead of an