src/library/utils/R/URLencode.R

#  File src/library/utils/R/URLencode.R
#  Part of the R package, https://www.R-project.org
#
#  Copyright (C) 1995-2015 The R Core Team
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  A copy of the GNU General Public License is available at
#  https://www.R-project.org/Licenses/

URLencode <- function(URL, reserved = FALSE, repeated = FALSE)
{
    if(!repeated && grepl("%[[:xdigit:]]{2}", URL, useBytes = TRUE))
        return(URL)
    ## It is unsafe to use ranges here as collation is locale-dependent.
    ## We want to do this on characters and not on bytes.
    OK <- paste0("[^",
                 if(!reserved) "][!$&'()*+,;=:/?@#",
                 "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
                 "abcdefghijklmnopqrstuvwxyz0123456789._~-",
                 "]")
    x <- strsplit(URL, "")[[1L]]
    z <- grep(OK, x)
    if(length(z)) {
        y <- vapply(x[z],
                    function(x)
                        paste0("%", toupper(as.character(charToRaw(x))),
                               collapse = ""),
                    "")
        x[z] <- y
    }
    paste(x, collapse = "")
}

URLdecode <- function(URL)
{
    x <- charToRaw(URL)
    pc <- charToRaw("%")
    out <- raw(0L)
    i <- 1L
    while(i <= length(x)) {
        if(x[i] != pc) {
            out <- c(out, x[i])
            i <- i + 1L
        } else {
            y <- as.integer(x[i + 1L:2L])
            y[y > 96L] <- y[y > 96L] - 32L # a-f -> A-F
            y[y > 57L] <- y[y > 57L] - 7L  # A-F
            y <- sum((y - 48L) * c(16L, 1L))
            out <- c(out, as.raw(as.character(y)))
            i <- i + 3L
        }
    }
    rawToChar(out)
}