These two functions are used to collect the contents of the header of
an HTTP response via the headerfunction option of a curl handle
and then processing that text into both the name: value pairs
and also the initial line of the response that provides the
status of the request.
basicHeaderGatherer is a simple special case of
basicTextGatherer with the built-in post-processing
step done by parseHTTPHeader.
basicHeaderGatherer(txt = character(), max = NA)
parseHTTPHeader(lines, multi = TRUE)any initial text that we want included with the header.
This is passed to basicTextGatherer. Generally it
should not be specified unless there is a good reason.
This is passed directly to
basicTextGatherer
the text as a character vector from the response header
that
parseHTTPHeader will convert to a status and name-value
pairs.
a logical value controlling whether we check for
multiple HTTP headers in the lines of text. This is caused
by a Continue being concatenated with the actual response.
When this is TRUE, we look for the lines
that start an HTTP header, e.g. HTTP 200 ...,
and we use the content from the last of these.
The return value is the same as basicTextGatherer,
i.e. a list with
update, value and reset function elements.
The value element will invoke parseHTTPHeader
on the contents read during the processing of the libcurl request
and return that value.
Curl homepage http://curl.haxx.se
# NOT RUN {
if(url.exists("http://www.omegahat.net/RCurl/index.html")) withAutoprint({
h = basicHeaderGatherer()
getURI("http://www.omegahat.net/RCurl/index.html",
headerfunction = h$update)
names(h$value())
h$value()
})
# }
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