This task   (the reverse of   URL encoding   and distinct from   URL parser)   is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.



Test cases

   The encoded string   "http%3A%2F%2Ffoo%20bar%2F"   should be reverted to the unencoded form   "http://foo bar/".
   The encoded string   "google.com/search?q=%60Abdu%27l-Bah%C3%A1"   should revert to the unencoded form   "google.com/search?q=`Abdu'l-Bahá".


sub decode_url$(s$)
    local res$, ch$
 
    while(s$ <> "")
        ch$ = left$(s$, 1)
        if ch$ = "%" then
            ch$ = chr$(dec(mid$(s$, 2, 2)))
            s$ = right$(s$, len(s$) - 3)
        else
            if ch$ = "+" ch$ = " "
            s$ = right$(s$, len(s$) - 1)
	endif
        res$ = res$ + ch$
    wend
    return res$
end sub
 
print decode_url$("http%3A%2F%2Ffoo%20bar%2F")
print decode_url$("google.com/search?q=%60Abdu%27l-Bah%C3%A1")