procedure translate_controls (char_range)
local
  replace_text ;
if translate_array = TPU$K_UNSPECIFIED then
   translate_array        := create_array (256,0);
   translate_array {0}    := '';
   translate_array {1}    := '';
   translate_array {2}    := '';
   translate_array {3}    := '';
   translate_array {4}    := '';
   translate_array {5}    := '';
   translate_array {6}    := '';
   translate_array {7}    := '';
   translate_array {8}    := '';
   translate_array {9}    := '';
   translate_array {10}    := '';
   translate_array {11}    := '';
   translate_array {12}    := '';
   translate_array {13}    := '';
   translate_array {14}    := '';
   translate_array {15}    := '';
   translate_array {16}    := '';
   translate_array {17}    := '';
   translate_array {18}    := '';
   translate_array {19}    := '';
   translate_array {20}    := '';
   translate_array {21}    := '';
   translate_array {22}    := '';
   translate_array {23}    := '';
   translate_array {24}    := '';
   translate_array {25}    := '';
   translate_array {26}    := '';
   translate_array {27}    := '';
   translate_array {28}    := '';
   translate_array {29}    := '';
   translate_array {30}    := '';
   translate_array {31}    := '';
   translate_array {127}    := '';
   translate_array {128}    := '';
   translate_array {129}    := '';
   translate_array {130}    := '';
   translate_array {131}    := '';
   translate_array {132}    := '';
   translate_array {133}    := '';
   translate_array {134}    := '';
   translate_array {135}    := '';
   translate_array {136}    := '';
   translate_array {137}    := '';
   translate_array {138}    := '';
   translate_array {139}    := '';
   translate_array {140}    := '';
   translate_array {141}    := '';
   translate_array {142}    := '';
   translate_array {143}    := '';
   translate_array {144}    := '';
   translate_array {145}    := '';
   translate_array {146}    := '';
   translate_array {147}    := '';
   translate_array {148}    := '';
   translate_array {149}    := '';
   translate_array {150}    := '';
   translate_array {151}    := '';
   translate_array {152}    := '';
   translate_array {153}    := '';
   translate_array {154}    := '';
   translate_array {155}    := '';
   translate_array {156}    := '';
   translate_array {157}    := '';
   translate_array {158}    := '';
   translate_array {159}    := '';
   translate_array {160}    := '';
   translate_array {164}    := '';
   translate_array {166}    := '';
   translate_array {172}    := '';
   translate_array {173}    := '';
   translate_array {174}    := '';
   translate_array {175}    := '';
   translate_array {180}    := '';
   translate_array {184}    := '';
   translate_array {190}    := '';
   translate_array {208}    := '';
   translate_array {222}    := '';
   translate_array {240}    := '';
   translate_array {254}    := '';
   translate_array {255}    := '';
endif;

if length (char_range) <> 1 then
   return 0 ;
endif;
                   
replace_text := translate_array {ascii (str (char_range))};
if replace_text = TPU$K_UNSPECIFIED then
   return 0;
endif;

erase (char_range);
copy_text (replace_text);
return 1;
endprocedure;
!------------------------------------------------------------------------------
procedure eve_clear_nonprint

constant
 ctrl_char_str :=
 ASCII (0)  + ASCII(1)  + ASCII(2)  + ASCII(3)  +
 ASCII (4)  + ASCII(5)  + ASCII(6)  + ASCII(7)  +
 ASCII (8)  + ASCII(9)  + ASCII(10)  + ASCII(11)  +
 ASCII (12)  + ASCII(13)  + ASCII(14)  + ASCII(15)  +
 ASCII (16)  + ASCII(17)  + ASCII(18)  + ASCII(19)  +
 ASCII (20)  + ASCII(21)  + ASCII(22)  + ASCII(23)  +
 ASCII (24)  + ASCII(25)  + ASCII(26)  + ASCII(27)  +
 ASCII (28)  + ASCII(29)  + ASCII(30)  + ASCII(31)  +
 ASCII (127)  + ASCII(128)  + ASCII(129)  + ASCII(130)  +
 ASCII (131)  + ASCII(132)  + ASCII(133)  + ASCII(134)  +
 ASCII (135)  + ASCII(136)  + ASCII(137)  + ASCII(138)  +
 ASCII (139)  + ASCII(140)  + ASCII(141)  + ASCII(142)  +
 ASCII (143)  + ASCII(144)  + ASCII(145)  + ASCII(146)  +
 ASCII (147)  + ASCII(148)  + ASCII(149)  + ASCII(150)  +
 ASCII (151)  + ASCII(152)  + ASCII(153)  + ASCII(154)  +
 ASCII (155)  + ASCII(156)  + ASCII(157)  + ASCII(158)  +
 ASCII (159)  + ASCII(160)  + ASCII(164)  + ASCII(166)  +
 ASCII (172)  + ASCII(173)  + ASCII(174)  + ASCII(175)  +
 ASCII (180)  + ASCII(184)  + ASCII(190)  + ASCII(208)  +
 ASCII (222)  + ASCII(240)  + ASCII(254)  + ASCII(255);

local
  ctrl_char_pattern,
  source_buffer,
  ctrl_char_range;

source_buffer := current_buffer;
eve_buffer ("translate_buffer");
erase (current_buffer);
copy_text (source_buffer);

ctrl_char_pattern := ANY (ctrl_char_str);
eve_top;

LOOP
  ctrl_char_range := search_quietly (ctrl_char_pattern, forward);
  exitif ctrl_char_range = 0;
  position (ctrl_char_range);
  if not translate_controls (ctrl_char_range) then
     move_horizontal (1);
  endif;
endloop;
endprocedure;
!------------------------------------------------------------------------------