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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/parser.R
\name{curl_parse_url}
\alias{curl_parse_url}
\title{Normalizing URL parser}
\usage{
curl_parse_url(url, baseurl = NULL, decode = TRUE, params = TRUE)
}
\arguments{
\item{url}{a character string of length one}
\item{baseurl}{use this as the parent if \code{url} may be a relative path}
\item{decode}{automatically \link[=curl_escape]{url-decode} output.
Set to \code{FALSE} to get output in url-encoded format.}
\item{params}{parse individual parameters assuming query is in \code{application/x-www-form-urlencoded} format.}
}
\description{
Interfaces the libcurl \href{https://curl.se/libcurl/c/libcurl-url.html}{URL parser}.
URLs are automatically normalized where possible, such as in the case of
relative paths or url-encoded queries (see examples).
When parsing hyperlinks from a HTML document, it is possible to set \code{baseurl}
to the location of the document itself such that relative links can be resolved.
}
\details{
A valid URL contains at least a scheme and a host, other pieces are optional.
If these are missing, the parser raises an error. Otherwise it returns
a list with the following elements:
\itemize{
\item \emph{url}: the normalized input URL
\item \emph{scheme}: the protocol part before the \verb{://} (required)
\item \emph{host}: name of host without port (required)
\item \emph{port}: decimal between 0 and 65535
\item \emph{path}: normalized path up till the \verb{?} of the url
\item \emph{query}: search query: part between the \verb{?} and \verb{#} of the url. Use \code{params} below to get individual parameters from the query.
\item \emph{fragment}: the hash part after the \verb{#} of the url
\item \emph{user}: authentication username
\item \emph{password}: authentication password
\item \emph{params}: named vector with parameters from \code{query} if set
}
Each element above is either a string or \code{NULL}, except for \code{params} which
is always a character vector with the length equal to the number of parameters.
Note that the \code{params} field is only usable if the \code{query} is in the usual
\code{application/x-www-form-urlencoded} format which is technically not part of
the RFC. Some services may use e.g. a json blob as the query, in which case
the parsed \code{params} field here can be ignored. There is no way for the parser
to automatically infer or validate the query format, this is up to the caller.
For more details on the URL format see
\href{https://datatracker.ietf.org/doc/html/rfc3986}{rfc3986}
or the steps explained in the \href{https://url.spec.whatwg.org/#concept-basic-url-parser}{whatwg basic url parser}.
On platforms that do not have a recent enough curl version (basically only
RHEL-8) the \href{https://github.com/ada-url/ada}{Ada URL} library is used as fallback.
Results should be identical, though curl has nicer error messages. This is
a temporary solution, we plan to remove the fallback when old systems are
no longer supported.
}
\examples{
url <- "https://jerry:secret@google.com:888/foo/bar?test=123#bla"
curl_parse_url(url)
# Resolve relative links from a baseurl
curl_parse_url("/somelink", baseurl = url)
# Paths get normalized
curl_parse_url("https://foobar.com/foo/bar/../baz/../yolo")$url
# Also normalizes URL-encoding (these URLs are equivalent):
url1 <- "https://ja.wikipedia.org/wiki/\u5bff\u53f8"
url2 <- "https://ja.wikipedia.org/wiki/\%e5\%af\%bf\%e5\%8f\%b8"
curl_parse_url(url1)$path
curl_parse_url(url2)$path
curl_parse_url(url1, decode = FALSE)$path
curl_parse_url(url1, decode = FALSE)$path
}
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