--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/docs/libcurl/opts/CURLOPT_IOCTLFUNCTION.3	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,92 @@
+.\" **************************************************************************
+.\" *                                  _   _ ____  _
+.\" *  Project                     ___| | | |  _ \| |
+.\" *                             / __| | | | |_) | |
+.\" *                            | (__| |_| |  _ <| |___
+.\" *                             \___|\___/|_| \_\_____|
+.\" *
+.\" * Copyright (C) 1998 - 2017, 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 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
+.\" * furnished to do so, under the terms of the COPYING file.
+.\" *
+.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+.\" * KIND, either express or implied.
+.\" *
+.\" **************************************************************************
+.\"
+.TH CURLOPT_IOCTLFUNCTION 3 "16 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
+.SH NAME
+CURLOPT_IOCTLFUNCTION \- callback for I/O operations
+.SH SYNOPSIS
+.nf
+#include <curl/curl.h>
+
+typedef enum {
+  CURLIOE_OK,            /* I/O operation successful */
+  CURLIOE_UNKNOWNCMD,    /* command was unknown to callback */
+  CURLIOE_FAILRESTART,   /* failed to restart the read */
+  CURLIOE_LAST           /* never use */
+} curlioerr;
+
+typedef enum  {
+  CURLIOCMD_NOP,         /* no operation */
+  CURLIOCMD_RESTARTREAD, /* restart the read stream from start */
+  CURLIOCMD_LAST         /* never use */
+} curliocmd;
+
+curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp);
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IOCTLFUNCTION, ioctl_callback);
+.SH DESCRIPTION
+Pass a pointer to your callback function, which should match the prototype
+shown above.
+
+This callback function gets called by libcurl when something special
+I/O-related needs to be done that the library can't do by itself. For now,
+rewinding the read data stream is the only action it can request. The
+rewinding of the read data stream may be necessary when doing an HTTP PUT or
+POST with a multi-pass authentication method.
+
+The callback MUST return \fICURLIOE_UNKNOWNCMD\fP if the input \fIcmd\fP is
+not \fICURLIOCMD_RESTARTREAD\fP.
+
+The \fIclientp\fP argument to the callback is set with the
+\fICURLOPT_IOCTLDATA(3)\fP option.
+
+This option is deprecated! Do not use it. Use \fICURLOPT_SEEKFUNCTION(3)\fP
+instead to provide seeking! If \fICURLOPT_SEEKFUNCTION(3)\fP is set, this
+parameter will be ignored when seeking.
+.SH DEFAULT
+By default, this parameter is set to NULL. Not used.
+.SH PROTOCOLS
+Used with HTTP
+.SH EXAMPLE
+.nf
+static curlioerr ioctl_callback(CURL *handle, int cmd, void *clientp)
+{
+  struct data *io = (struct data *)clientp;
+  if(cmd == CURLIOCMD_RESTARTREAD) {
+    lseek(fd, 0, SEEK_SET);
+    current_offset = 0;
+    return CURLIOE_OK;
+  }
+  return CURLIOE_UNKNOWNCMD;
+}
+{
+  struct data ioctl_data;
+  curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_callback);
+  curl_easy_setopt(curl, CURLOPT_IOCTLDATA, &ioctl_data);
+}
+.fi
+.SH AVAILABILITY
+Added in 7.12.3
+.SH RETURN VALUE
+Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
+.SH "SEE ALSO"
+.BR CURLOPT_IOCTLDATA "(3), " CURLOPT_SEEKFUNCTION "(3), "