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CURLOPT_WRITEHEADER: clarify the docs

This commit is contained in:
Daniel Stenberg 2011-06-10 13:17:17 +02:00
parent 36a22f9074
commit d5cc77b744

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@ -343,10 +343,10 @@ Function pointer that should match the following prototype: \fIsize_t
function( void *ptr, size_t size, size_t nmemb, void *userdata);\fP. This
function gets called by libcurl as soon as it has received header data. The
header callback will be called once for each header and only complete header
lines are passed on to the callback. Parsing headers should be easy enough
using this. The size of the data pointed to by \fIptr\fP is \fIsize\fP
multiplied with \fInmemb\fP. Do not assume that the header line is zero
terminated! The pointer named \fIuserdata\fP is the one you set with the
lines are passed on to the callback. Parsing headers is very easy using
this. The size of the data pointed to by \fIptr\fP is \fIsize\fP multiplied
with \fInmemb\fP. Do not assume that the header line is zero terminated! The
pointer named \fIuserdata\fP is the one you set with the
\fICURLOPT_WRITEHEADER\fP option. The callback function must return the number
of bytes actually taken care of. If that amount differs from the amount passed
to your function, it'll signal an error to the library. This will abort the
@ -365,19 +365,20 @@ negotiation. If you need to operate on only the headers from the final
response, you will need to collect headers in the callback yourself and use
HTTP status lines, for example, to delimit response boundaries.
Since 7.14.1: When a server sends a chunked encoded transfer, it may contain a
trailer. That trailer is identical to a HTTP header and if such a trailer is
received it is passed to the application using this callback as well. There
are several ways to detect it being a trailer and not an ordinary header: 1)
it comes after the response-body. 2) it comes after the final header line (CR
LF) 3) a Trailer: header among the response-headers mention what header to
expect in the trailer.
When a server sends a chunked encoded transfer, it may contain a trailer. That
trailer is identical to a HTTP header and if such a trailer is received it is
passed to the application using this callback as well. There are several ways
to detect it being a trailer and not an ordinary header: 1) it comes after the
response-body. 2) it comes after the final header line (CR LF) 3) a Trailer:
header among the regular response-headers mention what header(s) to expect in
the trailer.
.IP CURLOPT_WRITEHEADER
(This option is also known as \fBCURLOPT_HEADERDATA\fP) Pass a pointer to be
used to write the header part of the received data to. If you don't use your
own callback to take care of the writing, this must be a valid FILE *. See
also the \fICURLOPT_HEADERFUNCTION\fP option above on how to set a custom
get-all-headers callback.
used to write the header part of the received data to. If you don't use
\fICURLOPT_WRITEFUNCTION\fP or \fICURLOPT_HEADERFUNCTION\fP to take care of
the writing, this must be a valid FILE * as the internal default will then be
a plain fwrite(). See also the \fICURLOPT_HEADERFUNCTION\fP option above on
how to set a custom get-all-headers callback.
.IP CURLOPT_DEBUGFUNCTION
Function pointer that should match the following prototype: \fIint
curl_debug_callback (CURL *, curl_infotype, char *, size_t, void *);\fP