/* decode %xx hex values in string to ascii
 * Written by Harry Sintonen <sintonen@iki.fi>
 * Public Domain.
 */

options results

a = arg(1)
say a 'decoded: 'decode(a)
exit 0

decode: PROCEDURE
  v = arg(1)
  l = length(v)
  r = ''
  do i = 1 to l
    c = substr(v, i, 1)
    if c  == '%' & i <= l - 2 then do
      hex = substr(v, i + 1, 2)
      if datatype(hex, 'X') then do
        dec = x2d(hex)
        /* filter out ctrlcodes */
        if ((dec >= 32 & dec <= 126) | dec >= 160) then r = r || x2c(hex)
        else r = r || '?'
        i = i + 2
      end
      else r = r || c
    end
    else r = r || c
  end
  return r