subroutineurl_quote

subroutine url_quote(text, out)
    character(len=*), intent(in) :: text                !! the text
    character(len=:), allocatable, intent(out) :: out   !! the result
    character(len=*), parameter :: HEX = '0123456789ABCDEF'
    character(len=*), parameter :: SAFE = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.-~/'
    integer :: k, c

    out = ''
    do k = 1, len(text)
        if (index(SAFE, text(k:k)) > 0) then
            out = out//text(k:k)
        else
            c = iand(ichar(text(k:k)), 255)
            out = out//'%'//HEX(c/16 + 1:c/16 + 1)//HEX(mod(c, 16) + 1:mod(c, 16) + 1)
        end if
    end do
end subroutine url_quote