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.TH CURLOPT_CHUNK_BGN_FUNCTION 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_CHUNK_BGN_FUNCTION \- callback before a transfer with FTP wildcardmatch
.SH SYNOPSIS
.nf
#include <curl/curl.h>

long chunk_bgn_callback(const void *transfer_info, void *ptr,
                        int remains);

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CHUNK_BGN_FUNCTION,
                          chunk_bgn_callback);
.SH DESCRIPTION
Pass a pointer to your callback function, which should match the prototype
shown above.

This callback function gets called by libcurl before a part of the stream is
going to be transferred (if the transfer supports chunks).

The \fItransfer_info\fP pointer will point to a struct curl_fileinfo with
details about the file that is about to get transferred.

This callback makes sense only when using the \fICURLOPT_WILDCARDMATCH(3)\fP
option for now.

The target of transfer_info parameter is a "feature depended" structure. For
the FTP wildcard download, the target is curl_fileinfo structure (see
\fIcurl/curl.h\fP).  The parameter \fIptr\fP is a pointer given by
\fICURLOPT_CHUNK_DATA(3)\fP. The parameter remains contains number of chunks
remaining per the transfer. If the feature is not available, the parameter has
zero value.

Return \fICURL_CHUNK_BGN_FUNC_OK\fP if everything is fine,
\fICURL_CHUNK_BGN_FUNC_SKIP\fP if you want to skip the concrete chunk or
\fICURL_CHUNK_BGN_FUNC_FAIL\fP to tell libcurl to stop if some error occurred.
.SH DEFAULT
NULL
.SH PROTOCOLS
FTP
.SH EXAMPLE
TODO
.SH AVAILABILITY
This was added in 7.21.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_CHUNK_END_FUNCTION "(3), " CURLOPT_WILDCARDMATCH "(3), "