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Diffstat (limited to 'docs/libcurl/opts/GNURLOPT_IOCTLFUNCTION.3')
| -rw-r--r-- | docs/libcurl/opts/GNURLOPT_IOCTLFUNCTION.3 | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/docs/libcurl/opts/GNURLOPT_IOCTLFUNCTION.3 b/docs/libcurl/opts/GNURLOPT_IOCTLFUNCTION.3 new file mode 100644 index 000000000..99bfd489a --- /dev/null +++ b/docs/libcurl/opts/GNURLOPT_IOCTLFUNCTION.3 @@ -0,0 +1,92 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2020, 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.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 GNURLOPT_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 <gnurl/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), " |