Strip control codes and extended characters from a string

The task is to strip control codes and extended characters from a string. The solution should demonstrate how to achieve each of the following results:

a string with control codes stripped (but extended characters not stripped)
a string with control codes and extended characters stripped

In ASCII, the control codes have decimal codes 0 through to 31 and 127. On an ASCII based system, if the control codes are stripped, the resultant string would have all of its characters within the range of 32 to 126 decimal on the ASCII table.

On a non-ASCII based system, we consider characters that do not have a corresponding glyph on the ASCII table (within the ASCII range of 32 to 126 decimal) to be an extended character for the purpose of this task.

Ada

<lang Ada>with Ada.Text_IO;

procedure Strip_ASCII is

  Full: String := 'a' & Character'Val(11) & 'b' & Character'Val(166) &
                  'c' & Character'Val(127) & Character'Val(203) &
                  Character'Val(202) & "de";
  -- 5 ordinary characters ('a' .. 'e')
  -- 2 control characters (11, 127); note that 11 is the "vertical tab"
  -- 3 extended characters (166, 203, 202)

  function Filter(S:     String;
                  From:  Character := ' ';
                  To:    Character := Character'Val(126);
                  Above: Character := Character'Val(127)) return String is
  begin
     if S'Length = 0 then
        return "";
     elsif (S(S'First) >= From and then S(S'First) <= To) or else S(S'First) > Above then
        return S(S'First) & Filter(S(S'First+1 .. S'Last), From, To, Above);
     else
        return Filter(S(S'First+1 .. S'Last), From, To, Above);
     end if;
  end Filter;

  procedure Put_Line(Text, S: String) is
  begin
     Ada.Text_IO.Put_Line(Text & " """ & S & """, Length:" & Integer'Image(S'Length));
  end Put_Line;

begin

  Put_Line("The full string :", Full);
  Put_Line("No Control Chars:", Filter(Full)); -- default values for From, To, and Above
  Put_Line("Neither_Extended:", Filter(Full, Above => Character'Last)); -- defaults for From and To

end Strip_ASCII; </lang>

Output:

The full string : "a
                    b�c��de", Length: 10
No Control Chars: "ab�c��de", Length: 8
Neither_Extended: "abcde", Length: 5

ALGOL 68

<lang algol68># remove control characters and optionally extended characters from the string text #

assums ASCII is the character set #

PROC strip characters = ( STRING text, BOOL strip extended )STRING:

    BEGIN
        # we build the result in a []CHAR and convert back to a string at the end #
        INT text start = LWB text;
        INT text max   = UPB text;
        [ text start : text max ]CHAR result;
        INT result pos := text start;
        FOR text pos FROM text start TO text max DO
            INT ch := ABS text[ text pos ];
            IF ( ch >= 0 AND ch <= 31 ) OR ch = 127 THEN
                # control character #
                SKIP
            ELIF strip extended AND ( ch > 126 OR ch < 0 ) THEN
                # extened character and we don't want them #
                SKIP
            ELSE
                # include this character #
                result[ result pos ] := REPR ch;
                result pos +:= 1
            FI
        OD;
        result[ text start : result pos - 1 ]
    END # strip characters # ;

test the control/extended character stripping procedure #

STRING t = REPR 2 + "abc" + REPR 10 + REPR 160 + "def~" + REPR 127 + REPR 10 + REPR 150 + REPR 152 + "!"; print( ( "<<" + t + ">> - without control characters: <<" + strip characters( t, FALSE ) + ">>", newline ) ); print( ( "<<" + t + ">> - without control or extended characters: <<" + strip characters( t, TRUE ) + ">>", newline ) )</lang>

Output:

<<�abc
ádef~?
ûÿ!>> - without control characters:             <<abcádef~ûÿ!>>
<<�abc
ádef~?
ûÿ!>> - without control or extended characters: <<abcdef~!>>

AutoHotkey

Translation of: Python

<lang AHK>Stripped(x){ Loop Parse, x if Asc(A_LoopField) > 31 and Asc(A_LoopField) < 128 r .= A_LoopField return r } MsgBox % stripped("`ba" Chr(00) "b`n`rc`fd" Chr(0xc3))</lang>

AWK

syntax: GAWK -f STRIP_CONTROL_CODES_AND_EXTENDED_CHARACTERS.AWK

BEGIN {

   s = "ab\xA2\x09z" # a b cent tab z
   printf("original string: %s (length %d)\n",s,length(s))
   gsub(/[\x00-\x1F\x7F]/,"",s); printf("control characters stripped: %s (length %d)\n",s,length(s))
   gsub(/[\x80-\xFF]/,"",s); printf("control and extended stripped: %s (length %d)\n",s,length(s))
   exit(0)

} </lang>

output:

original string: ab¢    z (length 5)
control characters stripped: ab¢z (length 4)
control and extended stripped: abz (length 3)

BASIC

Works with: QBasic

While DOS does support some extended characters, they aren't entirely standardized, and shouldn't be relied upon.

<lang qbasic>DECLARE FUNCTION strip$ (what AS STRING) DECLARE FUNCTION strip2$ (what AS STRING)

DIM x AS STRING, y AS STRING, z AS STRING

' tab c+cedilla eof x = CHR$(9) + "Fran" + CHR$(135) + "ais" + CHR$(26) y = strip(x) z = strip2(x)

PRINT "x:"; x PRINT "y:"; y PRINT "z:"; z

FUNCTION strip$ (what AS STRING)

   DIM outP AS STRING, L0 AS INTEGER, tmp AS STRING
   FOR L0 = 1 TO LEN(what)
       tmp = MID$(what, L0, 1)
       SELECT CASE ASC(tmp)
           CASE 32 TO 126
               outP = outP + tmp
       END SELECT
   NEXT
   strip$ = outP

END FUNCTION

FUNCTION strip2$ (what AS STRING)

   DIM outP AS STRING, L1 AS INTEGER, tmp AS STRING
   FOR L1 = 1 TO LEN(what)
       tmp = MID$(what, L1, 1)
       SELECT CASE ASC(tmp)
               'normal     accented    various     greek, math, etc.
           CASE 32 TO 126, 128 TO 168, 171 TO 175, 224 TO 253
               outP = outP + tmp
       END SELECT
   NEXT
   strip2$ = outP

END FUNCTION</lang>

Output:

x:      Français→
y:Franais
z:Français

See also: Liberty BASIC, PureBasic, Run BASIC

BBC BASIC

<lang bbcbasic> test$ = CHR$(9) + "Fran" + CHR$(231) + "ais." + CHR$(127)

     PRINT "Original ISO-8859-1 string: " test$ " (length " ; LEN(test$) ")"
     test$ = FNstripcontrol(test$)
     PRINT "Control characters stripped: " test$ " (length " ; LEN(test$) ")"
     test$ = FNstripextended(test$)
     PRINT "Control & extended stripped: " test$ " (length " ; LEN(test$) ")"
     END
     
     DEF FNstripcontrol(A$) : REM CHR$(127) is a 'control' code
     LOCAL I%
     WHILE I%<LEN(A$)
       I% += 1
       IF ASCMID$(A$,I%)<32 OR ASCMID$(A$,I%)=127 THEN
         A$ = LEFT$(A$,I%-1) + MID$(A$,I%+1)
       ENDIF
     ENDWHILE
     = A$
     
     DEF FNstripextended(A$)
     LOCAL I%
     WHILE I%<LEN(A$)
       I% += 1
       IF ASCMID$(A$,I%)>127 THEN
         A$ = LEFT$(A$,I%-1) + MID$(A$,I%+1)
       ENDIF
     ENDWHILE
     = A$</lang>

Output:

Original ISO-8859-1 string:  Français (length 11)
Control characters stripped: Français. (length 9)
Control & extended stripped: Franais. (length 8)

Bracmat

<lang bracmat>( "string of ☺☻♥♦⌂, may include control characters and other ilk.\L\D§►↔◄ Rødgrød med fløde"

 : ?string1
 : ?string2

& :?newString & whl

 ' ( @(!string1:?clean (%@:<" ") ?string1)
   & !newString !clean:?newString
   )

& !newString !string1:?newString & out$(str$("Control characters stripped: " str$!newString)) & :?newString & whl

 ' ( @(!string2:?clean (%@:(<" "|>"~")) ?string2)
   & !newString !clean:?newString
   )

& !newString !string2:?newString & out

 $ ( str
   $ ( "

Control characters and extended characters stripped: "

       str$!newString
     )
   )

& );</lang> Output:

Control characters stripped:
string of ⌂, may include controlcharacters and other ilk.§Rødgrød med fløde

Control characters and extended characters stripped:
string of , may include controlcharacters and other ilk.Rdgrd med flde

C

<lang C>#include <stdio.h>

include <stdlib.h>

define IS_CTRL (1 << 0)
define IS_EXT (1 << 1)
define IS_ALPHA (1 << 2)
define IS_DIGIT (1 << 3) /* not used, just give you an idea */

unsigned int char_tbl[256] = {0};

/* could use ctypes, but then they pretty much do the same thing */ void init_table() { int i;

for (i = 0; i < 32; i++) char_tbl[i] |= IS_CTRL; char_tbl[127] |= IS_CTRL;

for (i = 'A'; i <= 'Z'; i++) { char_tbl[i] |= IS_ALPHA; char_tbl[i + 0x20] |= IS_ALPHA; /* lower case */ }

for (i = 128; i < 256; i++) char_tbl[i] |= IS_EXT; }

/* depends on what "stripped" means; we do it in place.

* "what" is a combination of the IS_* macros, meaning strip if
* a char IS_ any of them
*/

void strip(char * str, int what) { unsigned char *ptr, *s = (void*)str; ptr = s; while (*s != '\0') { if ((char_tbl[(int)*s] & what) == 0) *(ptr++) = *s; s++; } *ptr = '\0'; }

int main() { char a[256]; int i;

init_table();

/* populate string with one of each char */ for (i = 1; i < 255; i++) a[i - 1] = i; a[255] = '\0'; strip(a, IS_CTRL); printf("%s\n", a);

for (i = 1; i < 255; i++) a[i - 1] = i; a[255] = '\0'; strip(a, IS_CTRL | IS_EXT); printf("%s\n", a);

for (i = 1; i < 255; i++) a[i - 1] = i; a[255] = '\0'; strip(a, IS_CTRL | IS_EXT | IS_ALPHA); printf("%s\n", a);

return 0; }</lang>output:<lang> !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ <odd stuff my xterm thinks are bad unicode hence can't be properly shown>

!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
!"#$%&'()*+,-./0123456789:;<=>?@[\]^_`{|}~</lang>

C++

<lang Cpp>#include <string>

include <iostream>
include <algorithm>
include <boost/lambda/lambda.hpp>
include <boost/lambda/casts.hpp>
include <ctime>
include <cstdlib>

using namespace boost::lambda ;

struct MyRandomizer {

  char operator( )( ) {
     return static_cast<char>( rand( ) % 256 ) ;
  }

} ;

std::string deleteControls ( std::string startstring ) {

  std::string noControls( "                                        " ) ;//creating space for 
  //the standard algorithm remove_copy_if
  std::remove_copy_if( startstring.begin( ) , startstring.end( ) , noControls.begin( ) ,

ll_static_cast<int>( _1 ) < 32 && ll_static_cast<int>( _1 ) == 127 ) ;

  return noControls ;

}

std::string deleteExtended( std::string startstring ) {

  std::string noExtended ( "                                        " ) ;//same as above
  std::remove_copy_if( startstring.begin( ) , startstring.end( ) , noExtended.begin( ) ,

ll_static_cast<int>( _1 ) > 127 || ll_static_cast<int>( _1 ) < 32 ) ;

  return noExtended ;

}

int main( ) {

  std::string my_extended_string ;
  for ( int i = 0 ; i < 40 ; i++ ) //we want the extended string to be 40 characters long
     my_extended_string.append( " " ) ;
  srand( time( 0 ) ) ;
  std::generate_n( my_extended_string.begin( ) , 40 , MyRandomizer( ) ) ;
  std::string no_controls( deleteControls( my_extended_string ) ) ;
  std::string no_extended ( deleteExtended( my_extended_string ) ) ;
  std::cout << "string with all characters: " << my_extended_string << std::endl ;
  std::cout << "string without control characters: " << no_controls << std::endl ;
  std::cout << "string without extended characters: " << no_extended << std::endl ;
  return 0 ;

}</lang> Output:

string with all characters: K�O:~���7�5����
���W��@>��ȓ�q�Q@���W-
string without control characters: K�O:~���7�5����
���W��@>��ȓ�q�Q@���W-
string without extended characters: KO:~75W@>qQ@W-

C#

Uses the test string from REXX. <lang csharp> using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;

namespace RosettaCode {

   class Program
   {
       static void Main(string[] args)
       {
           string test = "string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄";
           Console.WriteLine("Original: {0}", test);
           Console.WriteLine("Stripped of control codes: {0}", StripControlChars(test));
           Console.WriteLine("Stripped of extended: {0}", StripExtended(test));
       }

       static string StripControlChars(string arg)
       {
           char[] arrForm = arg.ToCharArray();
           StringBuilder buffer = new StringBuilder(arg.Length);//This many chars at most
           
           foreach(char ch in arrForm)
               if (!Char.IsControl(ch)) buffer.Append(ch);//Only add to buffer if not a control char

           return buffer.ToString();
       }

       static string StripExtended(string arg)
       {
           StringBuilder buffer = new StringBuilder(arg.Length); //Max length
           foreach(char ch in arg)
           {
               UInt16 num = Convert.ToUInt16(ch);//In .NET, chars are UTF-16
               //The basic characters have the same code points as ASCII, and the extended characters are bigger
               if((num >= 32u) && (num <= 126u)) buffer.Append(ch);
           }
           return buffer.ToString();
       }
   }

} </lang> Output:

Original: string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄
Stripped of control codes: string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄
Stripped of extended: string of , may include control characters and other ilk.

Clojure

<lang clojure>; generate our test string of characters with control and extended characters (def range-of-chars (apply str (map char (range 256))))

filter out the control characters

(apply str (filter #(not (Character/isISOControl %)) range-of-chars))

filter to return String of characters that are between 32 - 126

(apply str (filter #(<= 32 (int %) 126) range-of-chars))</lang>

Common Lisp

> (defparameter *extended-ascii* (coerce (loop for i from 0 to 255 collect (code-char i)) 'string))

*EXTENDED-ASCII*
> (defparameter *control-codes-stripped* 
    (remove-if #'(lambda (c) 
                   (let ((x (char-code c)))
                     (or (< x 32) (= x 127))))
               *extended-ascii*))

*CONTROL-CODES-STRIPPED*
> *control-codes-stripped*

" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklm¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ"
> (defparameter *control-codes-and-extended-stripped* 
    (remove-if-not #'(lambda (c) (and (standard-char-p c) (graphic-char-p c)))
                   *extended-ascii*))

*CONTROL-CODES-AND-EXTENDED-STRIPPED*
> *control-codes-and-extended-stripped*

" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~"

D

<lang d>import std.traits;

S stripChars(S)(S s, bool function(dchar) pure nothrow mustStrip)

       pure nothrow if (isSomeString!S) {
   S result;
   foreach (c; s) {
       if (!mustStrip(c))
           result ~= c;
   }
   return result;

}

void main() {

   import std.stdio, std.uni;
   auto s = "\u0000\u000A abc\u00E9def\u007F";
   writeln(s.stripChars( &isControl ));
   writeln(s.stripChars( c => isControl(c) || c == '\u007F' ));
   writeln(s.stripChars( c => isControl(c) || c >= '\u007F' ));

}</lang>

Output:

 abcédef?
 abcédef
 abcdef

Erlang

Exported functions to be used by Update_a_configuration_file <lang Erlang> -module( strip_control_codes ).

-export( [is_not_control_code/1, is_not_control_code_nor_extended_character/1, task/0] ).

is_not_control_code( C ) when C > 127 -> true; is_not_control_code( C ) when C < 32; C =:= 127 -> false; is_not_control_code( _C ) -> true.

is_not_control_code_nor_extended_character( C ) when C > 127 -> false; is_not_control_code_nor_extended_character( C ) -> is_not_control_code( C ).

task() ->

   String = lists:seq( 0, 255 ),
   io:fwrite( "String (~p characters): ~s~n", [erlang:length(String), String] ),
   String_without_cc = lists:filter( fun is_not_control_code/1, String ),
   io:fwrite( "String without control codes (~p characters): ~s~n", [erlang:length(String_without_cc), String_without_cc] ),
   String_without_cc_nor_ec = lists:filter( fun is_not_control_code_nor_extended_character/1, String ),
   io:fwrite( "String without control codes nor extended characters (~p characters): ~s~n", [erlang:length(String_without_cc_nor_ec), String_without_cc_nor_ec] ).

</lang>

Output:

41> strip_control_codes:task().
String (256 characters): ^@^A^B^C^D^E^F^G^H     
^N^O^P^Q^R^S^T^U^V^W^X^Y^Z^[^\^]^^^_ !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~^ ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
String without control codes (223 characters):  !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
String without control codes nor extended characters (95 characters):  !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

F#

Uses test string from REXX. <lang fsharp> open System

let stripControl (arg:string) =

   String(Array.filter (fun x -> not (Char.IsControl(x))) (arg.ToCharArray()))

//end stripControl

let stripExtended (arg:string) =

   let numArr = Array.map (fun (x:char) -> Convert.ToUInt16(x)) (arg.ToCharArray()) in
   String([|for num in numArr do if num >= 32us && num <= 126us then yield Convert.ToChar(num) |])

//end stripExtended

[<EntryPoint>] let main args =

   let test = "string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄"
   printfn "Original: %s" test
   printfn "Stripped of controls: %s" (stripControl test)
   printfn "Stripped of extended: %s" (stripExtended test)
   0//main must return integer, much like in C/C++

</lang> Output:

Original: string of ☺☻♥♦?, may include control characters and other ilk.♫☼§►↔◄
Stripped of controls: string of ☺☻♥♦?, may include control characters and other ilk.♫☼§►↔◄
Stripped of extended: string of , may include control characters and other ilk.

Factor

<lang>USING: ascii kernel sequences ;

strip-control-codes ( str -- str' ) [ control? not ] filter ;

strip-control-codes-and-extended ( str -- str' )

   strip-control-codes [ ascii? ] filter ;</lang>

Forth

<lang forth>: strip ( buf len -- buf len' ) \ repacks buffer, so len' <= len

 over + over swap over ( buf dst limit src )
 do
   i c@ 32 127 within if
     i c@ over c! char+
   then
 loop
 over - ;</lang>

Fortran

<lang fortran>module stripcharacters implicit none

contains

 pure logical function not_control(ch)
   character, intent(in) :: ch
   not_control = iachar(ch) >= 32 .and. iachar(ch) /= 127
 end function not_control

 pure logical function not_extended(ch)
   character, intent(in) :: ch
   not_extended = iachar(ch) >= 32 .and. iachar(ch) < 127
 end function not_extended

 pure function strip(string,accept) result(str)
   character(len=*), intent(in) :: string
   character(len=len(string))   :: str
   interface
     pure logical function accept(ch)
       character, intent(in) :: ch
     end function except
   end interface
   integer :: i,n
   str = repeat(' ',len(string))
   n = 0
   do i=1,len(string)
     if ( accept(string(i:i)) ) then
       n = n+1
       str(n:n) = string(i:i)
     end if
   end do
 end function strip

end module stripcharacters

program test

 use stripcharacters
 
 character(len=256) :: string, str
 integer            :: ascii(256), i
 forall (i=0:255) ascii(i) = i
 forall (i=1:len(string)) string(i:i) = achar(ascii(i))
 write (*,*) string
 
 write (*,*) 'Control characters deleted:'
 str = strip(string,not_control)
 write (*,*) str

 forall (i=1:len(string)) string(i:i) = achar(ascii(i))
 write (*,*) 'Extended characters deleted:'
 write (*,*) strip(string,not_extended)

end program test </lang>

FreeBASIC

<lang freebasic>' FB 1.05.0 Win64

Function stripControlChars(s As Const String) As String

 If s = "" Then Return ""
 Dim count As Integer = 0
 Dim strip(0 To Len(s) - 1) As Boolean
 For i As Integer = 0 To Len(s) - 1
   For j As Integer = 0 To 31
     If s[i] = j OrElse s[i] = 127 Then 
       count += 1
       strip(i) = True
       Exit For 
     End If
   Next j
 Next i

 Dim buffer As String = Space(Len(s) - count)
 count  = 0  
 For i As Integer = 0 To Len(s) - 1
   If Not Strip(i) Then
     buffer[count] = s[i]
     count += 1
   End If
 Next
 Return buffer

End Function

Function stripExtendedChars(s As Const String) As String

 If s = "" Then Return ""
 Dim count As Integer = 0
 Dim strip(0 To Len(s) - 1) As Boolean
 For i As Integer = 0 To Len(s) - 1
   For j As Integer = 128 To 255
     If s[i] = j Then 
       count += 1
       strip(i) = True
       Exit For 
     End If
   Next j
 Next i

 Dim buffer As String = Space(Len(s) - count)
 count  = 0  
 For i As Integer = 0 To Len(s) - 1
   If Not Strip(i) Then
     buffer[count] = s[i]
     count += 1
   End If
 Next
 Return buffer

End Function

Dim s As String = !"\v\001The\t quick\255 \vbrown\127\f fox\156" Dim s1 As String = stripControlChars(s) Dim s2 As String = stripExtendedChars(s) Dim s3 As String = stripExtendedChars(s1)

' Under Windows console, code page 850 : ' "vertical tab" displays as ♂ ' "form feed" displays as ♀ ' Chr(1) displays as ☺ ' Chr(127) displays as ⌂ ' the other control characters do what it says on the tin ' Chr(156) displays as £ ' Chr(255) displays as space

Print "Before stripping :" , s Print "Ctl chars stripped :" , s1 Print "Ext chars stripped :" , s2 Print "Both sets stripped :" , s3 Print Print "Before stripping" , "Length => " ; Len(s) Print "Ctl chars stripped" , "Length => " ; Len(s1) Print "Ext chars stripped" , "Length => " ; Len(s2) Print "Both sets stripped" , "Length => " ; Len(s3) Print Print "Press any key to quit" Sleep</lang>

Output:

Before stripping   :        ♂☺The        quick  ♂brown⌂♀ fox£
Ctl chars stripped :        The quick  brown fox£
Ext chars stripped :        ♂☺The        quick ♂brown⌂♀ fox
Both sets stripped :        The quick brown fox

Before stripping            Length =>  27
Ctl chars stripped          Length =>  21
Ext chars stripped          Length =>  25
Both sets stripped          Length =>  19

Gambas

Click this link to run this code <lang gambas>Public Sub Main() Dim sString As String = "The\t \equick\n \fbrownfox \vcost £125.00 or €145.00 or $160.00 \bto \ncapture ©®" Dim sStd, sExtend As String Dim siCount As Short

For siCount = 32 To 126

 sStd &= Chr(siCount)

 sExtend &= Chr(siCount)

End '________________________________________________________________ Public Sub Check(sString As String, sCheck As String) As String Dim siCount As Short Dim sResult As String

For siCount = 1 To Len(sString)

 If InStr(sCheck, Mid(sString, siCount, 1)) Then sResult &= Mid(sString, siCount, 1)

End</lang> Output:

Original string: -      The      uick
 
brownfox ^Kcost £125.00 or €145.00 or $160.00to 
capture ©®

No extended characters: -       The quick brownfox cost 125.00 or 145.00 or $160.00 to capture 
With extended characters: -     The quick brownfox cost £125.00 or €145.00 or $160.00 to capture ©®

Go

Go works for ASCII and non-ASCII systems. The first pair of functions below interpret strings as byte strings, presumably useful for strings consisting of ASCII and 8-bit extended ASCII data. The second pair of functions interpret strings as UTF-8. <lang go>package main

import ( "golang.org/x/text/transform" "golang.org/x/text/unicode/norm" "fmt" "strings" )

// two byte-oriented functions identical except for operator comparing c to 127. func stripCtlFromBytes(str string) string { b := make([]byte, len(str)) var bl int for i := 0; i < len(str); i++ { c := str[i] if c >= 32 && c != 127 { b[bl] = c bl++ } } return string(b[:bl]) }

func stripCtlAndExtFromBytes(str string) string { b := make([]byte, len(str)) var bl int for i := 0; i < len(str); i++ { c := str[i] if c >= 32 && c < 127 { b[bl] = c bl++ } } return string(b[:bl]) }

// two UTF-8 functions identical except for operator comparing c to 127 func stripCtlFromUTF8(str string) string { return strings.Map(func(r rune) rune { if r >= 32 && r != 127 { return r } return -1 }, str) }

func stripCtlAndExtFromUTF8(str string) string { return strings.Map(func(r rune) rune { if r >= 32 && r < 127 { return r } return -1 }, str) }

// Advanced Unicode normalization and filtering, // see http://blog.golang.org/normalization and // http://godoc.org/golang.org/x/text/unicode/norm for more // details. func stripCtlAndExtFromUnicode(str string) string { isOk := func(r rune) bool { return r < 32 || r >= 127 } // The isOk filter is such that there is no need to chain to norm.NFC t := transform.Chain(norm.NFKD, transform.RemoveFunc(isOk)) // This Transformer could also trivially be applied as an io.Reader // or io.Writer filter to automatically do such filtering when reading // or writing data anywhere. str, _, _ = transform.String(t, str) return str }

const src = "déjà vu" + // precomposed unicode "\n\000\037 \041\176\177\200\377\n" + // various boundary cases "as⃝df̅" // unicode combining characters

func main() { fmt.Println("source text:") fmt.Println(src) fmt.Println("\nas bytes, stripped of control codes:") fmt.Println(stripCtlFromBytes(src)) fmt.Println("\nas bytes, stripped of control codes and extended characters:") fmt.Println(stripCtlAndExtFromBytes(src)) fmt.Println("\nas UTF-8, stripped of control codes:") fmt.Println(stripCtlFromUTF8(src)) fmt.Println("\nas UTF-8, stripped of control codes and extended characters:") fmt.Println(stripCtlAndExtFromUTF8(src)) fmt.Println("\nas decomposed and stripped Unicode:") fmt.Println(stripCtlAndExtFromUnicode(src)) }</lang> Output: (varies with display configuration)

source text:
déjà vu
� !~?��
as⃝df̅ 

as bytes, stripped of control codes:
déjà vu !~��as⃝df̅ 

as bytes, stripped of control codes and extended characters:
dj vu !~asdf 

as UTF-8, stripped of control codes:
déjà vu !~��as⃝df̅ 

as UTF-8, stripped of control codes and extended characters:
dj vu !~asdf

as decomposed and stripped Unicode:
deja vu !~asdf

Groovy

<lang Groovy>def stripControl = { it.replaceAll(/\p{Cntrl}/, ) } def stripControlAndExtended = { it.replaceAll(/[^\p{Print}]/, ) }</lang> Test: <lang Groovy>def text = (0..255).collect { (char) it }.join() def textMinusControl = text.findAll { int v = (char)it; v > 31 && v != 127 }.join() def textMinusControlAndExtended = textMinusControl.findAll {((char)it) < 128 }.join()

assert stripControl(text) == textMinusControl assert stripControlAndExtended(text) == textMinusControlAndExtended</lang>

Haskell

<lang Haskell>strip :: String -> String strip =

 filter
   (\x -- Though use of Data.Char functions like isAlpha, isDigit etc
       -- seems more probable.
      ->
       let o = fromEnum x
       in o > 31 && o < 126)

main :: IO () main = print $ strip "alphabetic 字母 with some less parochial parts"</lang>

Output:

"alphabetic  with some less parochial parts"

Icon and Unicon

We'll use deletec to remove unwanted characters (2nd argument) from a string (1st argument). The procedure below coerces types back and forth between string and cset. The character set of unwanted characters is the difference of all ASCII characters and the ASCII characters from 33 to 126. <lang Icon>procedure main(A) write(image(deletec(&ascii,&ascii--(&ascii)[33:127]))) end link strings </lang>

Library: Icon Programming Library

strings.icn provides deletec

The IPL procedure deletec is equivalent to this: <lang Icon>procedure deletec(s, c) #: delete characters

  result := ""
  s ? {
     while  result ||:= tab(upto(c)) do tab(many(c))
     return result ||:= tab(0)
     }

end</lang>

Output:

" !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}"

J

Solution: <lang j>stripControlCodes=: -.&(DEL,32{.a.) stripControlExtCodes=: ([ -. -.)&(32}.127{.a.)</lang> Usage: <lang j> mystring=: a. {~ ?~256 NB. ascii chars 0-255 in random order

  #mystring                       NB. length of string

256

  #stripControlCodes mystring     NB. length of string without control codes

223

  #stripControlExtCodes mystring  NB. length of string without control codes or extended chars

95

  #myunicodestring=: u: ?~1000     NB. unicode characters 0-999 in random order

1000

  #stripControlCodes myunicodestring

967

  #stripControlExtCodes myunicodestring

95

  stripControlExtCodes myunicodestring

k}w:]U3xEh9"GZdr/#^B.Sn%\uFOo[(`t2-J6*IA=Vf&N;lQ8,${XLz5?D0~s)'Y7Kq|ip4<WRCaM!b@cgv_T +mH>1ejPy</lang>

JavaScript

ES 5

<lang JavaScript>(function (strTest) {

   // s -> s
   function strip(s) {
       return s.split().filter(function (x) {
           var n = x.charCodeAt(0);
           
           return 31 < n && 127 > n;
       }).join();
   }

   return strip(strTest);

})("\ba\x00b\n\rc\fd\xc3");</lang>

Output:

Java

Works with: Java version 8+

<lang java>import java.util.function.IntPredicate;

public class StripControlCodes {

   public static void main(String[] args) {
       String s = "\u0000\n abc\u00E9def\u007F";
       System.out.println(stripChars(s, c -> c > '\u001F' && c != '\u007F'));
       System.out.println(stripChars(s, c -> c > '\u001F' && c < '\u007F'));
   }

   static String stripChars(String s, IntPredicate include) {
       return s.codePoints().filter(include::test).collect(StringBuilder::new,
               StringBuilder::appendCodePoint, StringBuilder::append).toString();
   }

}</lang>

 abcédef
 abcdef

jq

Works with: jq version 1.4

<lang jq>def strip_control_codes:

explode | map(select(. > 31 and . != 127)) | implode;

def strip_extended_characters:

 explode | map(select(31 < . and . < 127)) | implode;</lang>

Example: <lang jq>def string: "string of ☺☻♥♦⌂, may include control characters such as null(\u0000) and other ilk.\n§►↔◄\nRødgrød med fløde";

"string | strip_control_codes\n => \(string | strip_control_codes)", "string | strip_extended_characters\n => \(string | strip_extended_characters)"</lang>

Output:

<lang sh>$ jq -n -r -f Strip_control_codes_and_extended_characters.jq string | strip_control_codes

=> string of ☺☻♥♦⌂, may include control characters such as null() and other ilk.§►↔◄Rødgrød med fløde

string | strip_extended_characters

=> string of , may include control characters such as null() and other ilk.Rdgrd med flde</lang>

Julia

<lang Julia> stripc0{T<:String}(a::T) = replace(a, r"[\x00-\x1f\x7f]", "") stripc0x{T<:String}(a::T) = replace(a, r"[^\x20-\x7e]", "")

a = "a\n\tb\u2102d\u2147f"

println("Original String:\n ", a) println("\nWith C0 control characters removed:\n ", stripc0(a)) println("\nWith C0 and extended characters removed:\n ", stripc0x(a)) </lang>

Output:

Original String:
    a
        bℂdⅇf

With C0 control characters removed:
    abℂdⅇf

With C0 and extended characters removed:
    abdf

Kotlin

<lang scala>// version 1.1.2

fun String.strip(extendedChars: Boolean = false): String {

   val sb = StringBuilder()
   for (c in this) {
       val i = c.toInt()
       if (i in 32..126 || (!extendedChars && i >= 128)) sb.append(c)
   }
   return sb.toString()

}

fun main(args: Array<String>) {

   println("Originally:")
   val s = "123\tabc\u0007DEF\u007F+-*/€æŧðłþ"
   println("String = $s  Length = ${s.length}")
   println("\nAfter stripping control characters:")
   val t = s.strip()
   println("String = $t  Length = ${t.length}")
   println("\nAfter stripping control and extended characters:")
   val u = s.strip(true)
   println("String = $u  Length = ${u.length}")

}</lang>

Output:

Originally:
String = 123	abcDEF?+-*/€æŧðłþ  Length = 22

After stripping control characters:
String = 123abcDEF+-*/€æŧðłþ  Length = 19

After stripping control and extended characters:
String = 123abcDEF+-*/  Length = 13

Liberty BASIC

   all$ =""
   for i =0 to 255
       all$ =all$ +chr$( i)
   next i

   print "Original string of bytes.  ( chr$( 10) causes a CRLF.)"
   print all$
   print

   lessControl$ =controlStripped$( all$)
   print "With control codes stripped out."
   print lessControl$
   print

   lessExtendedAndControl$ =extendedStripped$( lessControl$)
   print "With extended codes stripped out too."
   print lessExtendedAndControl$

end

   function controlStripped$( i$)
       r$ =""
       for j =1 to len( i$)
           ch$ =mid$( i$, j, 1)
           if asc( ch$) >=32 then r$ =r$ +ch$
       next j
       controlStripped$ =r$
   end function

   function extendedStripped$( i$)
       r$ =""
       for j =1 to len( i$)
           ch$ =mid$( i$, j, 1)
           if asc( ch$) <=128 then r$ =r$ +ch$
       next j
       extendedStripped$ =r$
   end function

</lang>

Lua

<lang lua>function Strip_Control_Codes( str )

   local s = ""
   for i in str:gmatch( "%C+" ) do
	s = s .. i
   end
   return s

end

function Strip_Control_and_Extended_Codes( str )

   local s = ""
   for i = 1, str:len() do

if str:byte(i) >= 32 and str:byte(i) <= 126 then

 	    s = s .. str:sub(i,i)

end

   end
   return s

end

q = "" for i = 0, 255 do q = q .. string.char(i) end

print( Strip_Control_Codes(q) ) print( Strip_Control_and_Extended_Codes(q) )</lang>

 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“”•–—˜™š›œžŸ ¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

Mathematica

<lang Mathematica>stripCtrl[x_]:=StringJoin[Select[Characters[x], MemberQ[CharacterRange["!","~"]~Join~Characters[FromCharacterCode[Range[128,255]]],#]&]]

stripCtrlExt[x_]:=StringJoin[Select[Characters[x], MemberQ[CharacterRange["!","~"],#]&]]</lang>

Test:

CompleteSet=FromCharacterCode[Range[0,255]]
->\.00\.02\.03\.04\.05\.06\.07\.08\.0b\.0e\.0f\.10\.11\.12\.13\.14
\.15\.16\.17\.18\.19\.1a\[RawEscape]\.1c\.1d\.1e\.1f !"#$%&'()*+,-./
0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]
^_`abcdefghijklmnopqrstuvwxyz{|}~? ¡¢£¤¥¦§¨©ª«\[Not]®¯\[Degree]
\[PlusMinus]\.b2\.b3\.b4\[Micro]\[Paragraph]\[CenterDot]¸¹º»¼½¾¿
ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ*ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö/øùúûüýþÿ

stripCtrl[CompleteSet]
->!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]
^_`abcdefghijklmnopqrstuvwxyz{|}~ ¡¢£¤¥¦§¨©ª«\[Not]®¯\[Degree]
\[PlusMinus]\.b2\.b3\.b4\[Micro]\[Paragraph]\[CenterDot]
¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ*ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö
/øùúûüýþÿ

stripCtrlExt[CompleteSet]
->!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]
^_`abcdefghijklmnopqrstuvwxyz{|}~

MATLAB / Octave

<lang MATLAB> function str = stripped(str)

   str = str(31<str & str<127); 
 end; </lang>

Nim

<lang nim>proc stripped(str): string =

 result = ""
 for c in str:
   if ord(c) in 32..126:
     result.add c

echo stripped "\ba\x00b\n\rc\fd\xc3"</lang> Output:

abcd

OCaml

<lang ocaml>let is_control_code c =

 let d = int_of_char c in
 d < 32 || d = 127

let is_extended_char c =

 let d = int_of_char c in
 d > 127

let strip f str =

 let len = String.length str in
 let res = String.create len in
 let rec aux i j =
   if i >= len then String.sub res 0 j else
   if f str.[i]
   then aux (succ i) j
   else begin
     res.[j] <- str.[i];
     aux (succ i) (succ j)
   end
 in
 aux 0 0

let () =

 let len = 32 in
 let s = String.create len in
 Random.self_init();
 for i = 0 to pred len do
   s.[i] <- char_of_int (Random.int 256)
 done;
 print_endline (strip is_control_code s);
 print_endline (strip (fun c -> (is_control_code c) || (is_extended_char c)) s);

</lang>

Pascal

Works with: Free_Pascal

<lang pascal>program StripCharacters(output);

function Strip (s: string; control, extended: boolean): string;

 var
   index: integer;
 begin
   Strip := ;
   for index:= 1 to length(s) do
   if not ((control and (ord(s[index]) <= 32)) or (extended and (ord(s[index]) > 127))) then
     Strip := Strip + s[index];
 end;

var

 test: string;
 i: integer;

begin

 setlength(test, 40);
 randomize;
 for i := 1 to length(test) do
   test[i] := char(1 + random(255));
 writeln ('Original: ', test);
 writeln ('No CNTL:  ', Strip(test, true,  false));
 writeln ('No extnd: ', Strip(test, false, true));
 writeln ('ASCII:    ', Strip(test, true,  true));

end.</lang> Output:

% ./StripCharacters 
Original: )?z8i9?a?K??N?s?F˪w?a??s
                                  #?b?B}PT?ٜ
No CNTL:  )?z8i9?a?K??N?s?F˪w?a??s#?b?B}PT?ٜ
No extnd: )z8i9aKNsFwas
                       #bB}PT
ASCII:    )z8i9aKNsFwas#bB}PT

Peloton

Peloton has a native instruction for removing control codes from a string, SAL, the Low ASCII Strip. From the manual: <lang sgml>Create variable with control characters: <@ SAYLETVARLIT>i|This string has control characters - - - - - -

in it</@> Strip control characters <@ SAYSALVAR>i</@> Assign infix <@ LETVARSALVAR>j|i</@> <@ SAYVAR>j</@> Assign prepend <@ LETSALVARVAR>k|i</@> <@ SAYVAR>k</@> Reflexive assign <@ ACTSALVAR>i</@> <@ SAYVAR>i</@></lang>

Peloton also has SAH, High ASCII Strip. Again, from the manual: <lang sgml>Create variable with high and low ANSI: <@ SAYLETVARLIT>i|This string has both low ansi and high ansi characters - il doit d'être prévenu</@> Strip high ANSI <@ SAYSAHVAR>i</@> Assign infix <@ LETVARSAHVAR>j|i</@> <@ SAYVAR>j</@> Assign prepend <@ LETSAHVARVAR>k|i</@> <@ SAYVAR>k</@> Reflexive assign <@ ACTSAHVAR>i</@> <@ SAYVAR>i</@></lang>

Perl

<lang Perl>#!/usr/bin/perl -w use strict ;

my @letters ; my @nocontrols ; my @noextended ; for ( 1..40 ) {

  push @letters ,  int( rand( 256 ) ) ;

} print "before sanitation : " ; print join( , map { chr( $_ ) } @letters ) ; print "\n" ; @nocontrols = grep { $_ > 32 && $_ != 127 } @letters ; print "Without controls: " ; print join( , map { chr( $_ ) } @nocontrols ) ; @noextended = grep { $_ < 127 } @nocontrols ; print "\nWithout extended: " ; print join( , map { chr( $_ ) } @noextended ) ; print "\n" ;</lang> Output:

before sanitation : �L08&YH�O��n)�:���O�G$���.���"zO���Q�?��
Without controls: �L08&YH�O��n)�:�O�G$���.���"zO��Q�?��
Without extended: L08&YHOn):OG$."zOQ?

Perl 6

<lang perl6>my $str = (0..400).roll(80)».chr.join;

say $str; say $str.subst(/<[ ^@..^_ ]>/, , :g); say $str.subst(/<-[ \ ..~ ]>/, , :g);</lang>

�¶ØèúđkƌĘ�r=êıƏÄÙÍy1SGa%TÑ�ęMRŅ�EŧİÌŬńĩµ9ŒďĔÜÉĈĬzĳdś5FúŨƏźƅíýÛÃņGÏ
                                                                      ö~ƀRÑú
¶ØèúđkƌĘr=êıƏÄÙÍy1SGa%TÑęMRŅEŧİÌŬńĩµ9ŒďĔÜÉĈĬzĳdś5FúŨƏźƅíýÛÃņGÏö~ƀRÑú
kr=y1SGa%TMRE9zd5FG~R

PicoLisp

Control characters in strings are written with a hat (^) in PicoLisp. ^? is the DEL character. <lang PicoLisp>(de stripCtrl (Str)

  (pack
     (filter
        '((C)
           (nor (= "^?" C) (> " " C "^A")) )
        (chop Str) ) ) )

(de stripCtrlExt (Str)

  (pack
     (filter
        '((C) (> "^?" C "^_"))
        (chop Str) ) ) )</lang>

Test:

: (char "^?")
-> 127

: (char "^_")
-> 31

: (stripCtrl "^I^M a b c^? d äöüß")
-> " a b c d äöüß"

: (stripCtrlExt "^I^M a b c^? d äöüß")
-> " a b c d "

Pike

<lang Pike>> string input = random_string(100); > (string)((array)input-enumerate(32)-enumerate(255-126,1,127)); Result: "p_xx08M]cK<FHgR3\\I.x>)Tm<VgakYddy&P7"</lang>

PL/I

<lang PL/I> stripper: proc options (main);

  declare s character (100) varying;
  declare i fixed binary;

  s = 'the quick brown fox jumped';
  /* A loop to replace blanks with control characters */
  do i = 1 to length(s);
     if substr(s, i, 1) = ' ' then
        substr(s, i, 1) = '01'x;
  end;
  put skip list (s);

  call stripcc (s);
  put skip list (s);

  s = 'now is the time for all good men';
  /* A loop to replace blanks with control characters */
  do i = 1 to length(s);
     if substr(s, i, 1) = ' ' then
        substr(s, i, 1) = 'A1'x;
  end;
  put skip list (s);

  call stripex (s);
  put skip list (s);

/* Strip control codes. */ stripcc: procedure (s);

  declare s character (*) varying;
  declare w character (length(s));
  declare c character (1);
  declare (i, j) fixed binary;

  j = 0;
  do i = 1 to length (s);
     c = substr(s, i, 1);
     if unspec(c) >= '00100000'b | unspec(c) = '01111111'b then
        do;
           j = j + 1;
           substr(w, j, 1) = c;
        end;
  end;
  s = substr(w, 1, j);

end stripcc;

/* Strips control codes and extended characters. */ stripex: procedure (s);

  declare s character (*) varying;
  declare w character (length(s));
  declare c character (1);
  declare (i, j) fixed binary;

  j = 0;
  do i = 1 to length (s);
     c = substr(s, i, 1);
     if unspec(c) >= '00100000'b & unspec(c) < '01111111'b then
        do;
           j = j + 1;
           substr(w, j, 1) = c;
        end;
  end;
  s = substr(w, 1, j);

end stripex;

end stripper; </lang> Output:

the�quick�brown�fox�jumped 
thequickbrownfoxjumped 
now¡is¡the¡time¡for¡all¡good¡men 
nowisthetimeforallgoodmen

PowerShell

<lang PowerShell> function Remove-Character {

   [CmdletBinding(DefaultParameterSetName="Control and Extended")]
   [OutputType([string])]
   Param
   (
       [Parameter(Mandatory=$true,
                  ValueFromPipeline=$true,
                  ValueFromPipelineByPropertyName=$true,
                  Position=0)]
       [string]
       $String,

       [Parameter(ParameterSetName="Control")]
       [switch]
       $Control,

       [Parameter(ParameterSetName="Extended")]
       [switch]
       $Extended
   )

   Begin
   {
       filter Remove-ControlCharacter
       {
           $_.ToCharArray() | ForEach-Object -Begin {$out = ""} -Process {if (-not [Char]::IsControl($_)) {$out += $_ }} -End {$out}
       }

       filter Remove-ExtendedCharacter
       {
           $_.ToCharArray() | ForEach-Object -Begin {$out = ""} -Process {if ([int]$_ -lt 127) {$out += $_ }} -End {$out}
       }
   }
   Process
   {
       foreach ($s in $String)
       {
           switch ($PSCmdlet.ParameterSetName)
           {
               "Control"  {$s | Remove-ControlCharacter}
               "Extended" {$s | Remove-ExtendedCharacter}
               Default    {$s | Remove-ExtendedCharacter | Remove-ControlCharacter}
           }
       }
   }

} </lang>

<lang PowerShell> $test = "$([char]9)Français."

"Original string : `"$test`"" "Control characters stripped : `"$($test | Remove-Character -Control)`"" "Extended characters stripped : `"$($test | Remove-Character -Extended)`"" "Control & extended stripped : `"$($test | Remove-Character)`"" </lang>

Output:

Original string              : "	Français."
Control characters stripped  : "Français."
Extended characters stripped : "	Franais."
Control & extended stripped  : "Franais."

<lang PowerShell> "Français", "Čeština" | Remove-Character -Extended </lang>

Output:

Franais
etina

PureBasic

<lang PureBasic>Procedure.s stripControlCodes(source.s)

 Protected i, *ptrChar.Character, length = Len(source), result.s
 *ptrChar = @source
 For i = 1 To length
   If *ptrChar\c > 31 
     result + Chr(*ptrChar\c)
   EndIf
   *ptrChar + SizeOf(Character)
 Next
 ProcedureReturn result

EndProcedure

Procedure.s stripControlExtCodes(source.s)

 Protected i, *ptrChar.Character, length = Len(source), result.s
 *ptrChar = @source
 For i = 1 To length
   If *ptrChar\c > 31 And *ptrChar\c < 128
     result + Chr(*ptrChar\c)
   EndIf
   *ptrChar + SizeOf(Character)
 Next
 ProcedureReturn result

EndProcedure

If OpenConsole()

 ;create sample string
 Define i, s.s
 For i = 1 To 80
   s + Chr(Random(254) + 1) ;include character values from 1 to 255
 Next

 PrintN(stripControlCodes(s))    ;string without control codes 
 PrintN("---------")
 PrintN(stripControlExtCodes(s)) ;string without control codes or extended chars
 
 Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
 CloseConsole()

EndIf</lang> Sample output:

»╫=┐C─≡G(═ç╤â√╝÷╔¬ÿ▌x  è4∞|)ï└⌐ƒ9²òτ┌ºáj)▓<~-vPÿφQ╨ù¿╖îFh"[ü╗dÉ₧q#óé├p╫■
---------
=CG(x 4|)9j)<~-vPQFh"[dq#p

Python

<lang Python>stripped = lambda s: "".join(i for i in s if 31 < ord(i) < 127)

print(stripped("\ba\x00b\n\rc\fd\xc3"))</lang>Output:<lang>abcd</lang>

Racket

lang racket

Works on both strings (Unicode) and byte strings (raw/ASCII)

(define (strip-controls str)

 (regexp-replace* #rx"[\0-\037\177]+" str ""))

(define (strip-controls-and-extended str)

 (regexp-replace* #rx"[^\040-\176]+" str ""))

</lang>

REXX

Note that guillemets were used as fences in presenting/displaying the «««before»»» and «««after»»» text strings.

idiomatic version

This REXX version processes each character in an idiomatic way (if it's a wanted character, then keep it). <lang rexx>/*REXX program strips all "control codes" from a character string (ASCII or EBCDIC). */ z= 'string of ☺☻♥♦⌂, may include control characters and other ♫☼§►↔◄░▒▓█┌┴┐±÷²¬└┬┘ilk.' @=' !"#$%&()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~' $=

  do j=1  for length(z);   _=substr(z, j, 1)    /*get a char from   X   one at a time. */
  if verify(_, @)==0  then $=$ || _             /*Is char in the @ list?   Then use it.*/
  end   /*j*/                                   /*stick a fork in it,  we're all done. */

say 'old = »»»'z"«««" /*add ««fence»» before & after old text*/ say 'new = »»»'$"«««" /* " " " " " new " */</lang>

output:

old = »»»string of ☺☻♥♦⌂, may include control characters and other    ♫☼§►↔◄░▒▓█┌┴┐±÷²¬└┬┘ilk.«««
new = »»»string of , may include control characters and other    ilk.«««

faster version

This REXX version only deletes unwanted characters.

It also shows a different way of performing concatenations (without using abutments, and a way to split a long literal (character) string.

Because there are (or should be) less unwanted characters than wanted characters, this version is faster. <lang rexx>/*REXX program strips all "control codes" from a character string (ASCII or EBCDIC). */ x= 'string of ☺☻♥♦⌂, may include control characters and other ♫☼§►↔◄░▒▓█┌┴┐±÷²¬└┬┘ilk.' @=' !"#$%&()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghij' || ,

                                             'klmnopqrstuvwxyz{|}~'

$=x /*set "new" string to same as the old. */

  do  until _=0;             _=verify($, @)     /*check if  any  character isn't in  @.*/
  if _\==0  then $=delstr($, _, 1)              /*Is this a bad char?   Then delete it.*/
  end   /*until*/                               /*stick a fork in it,  we're all done. */

say 'old = »»»' || x || "«««" /*add ««fence»» before & after old text*/ say 'new = »»»' || $ || "«««" /* " " " " " new " */</lang>

output is identical to the 1^st REXX version.

Ring

<lang ring> s = char(31) + "abc" + char(13) + "def" + char(11) + "ghi" + char(10) see strip(s) + nl

func strip str strip = "" for i = 1 to len(str)

   nr = substr(str,i,1)
   a = ascii(nr)
   if a > 31 and a < 123 and nr != "'" and nr != """"
      strip = strip + nr ok

next return strip </lang>

Ruby

<lang ruby>class String

 def strip_control_characters()
   chars.each_with_object("") do |char, str|
     str << char unless char.ascii_only? and (char.ord < 32 or char.ord == 127)
   end
 end
 
 def strip_control_and_extended_characters()
   chars.each_with_object("") do |char, str|
     str << char if char.ascii_only? and char.ord.between?(32,126)
   end
 end

end

p s = "\ba\x00b\n\rc\fd\xc3\x7ffoo" p s.strip_control_characters p s.strip_control_and_extended_characters</lang>

Output:

"\ba\u0000b\n\rc\fd\xC3\u007Ffoo"
"abcd\xC3foo"
"abcdfoo"

Run BASIC

<lang runbasic>s$ = chr$(31) + "abc" + chr$(13) + "def" + chr$(11) + "ghi" + chr$(10) print strip$(s$)

' ----------------------------------------- ' strip junk ' ----------------------------------------- FUNCTION strip$(str$) for i = 1 to len(str$)

 a$ = MID$(str$,i,1)
 a = ASC(a$)
 if a > 31 then
   if a <  123 then
     if a$ <> "'" then
       if a$ <> """" then
         strip$ = strip$ + a$
       end if
     end if
   end if
 end if

next i END FUNCTION</lang>

input  : chr$(31)+"abc"+chr$(13)+"def"+chr$(11)+"ghi"+chr$(10)
output : abcdefghi

Scala

ASCII: Using StringOps Class

<lang Scala>val controlCode : (Char) => Boolean = (c:Char) => (c <= 32 || c == 127) val extendedCode : (Char) => Boolean = (c:Char) => (c <= 32 || c > 127)

// ASCII test... val teststring = scala.util.Random.shuffle( (1.toChar to 254.toChar).toList ).mkString

println( "ctrl filtered out: \n\n" +

 teststring.filterNot(controlCode) + "\n" )

println( "ctrl and extended filtered out: \n\n" +

 teststring.filterNot(controlCode).filterNot(extendedCode) + "\n" )</lang>

Output:

ctrl filtered out:

?d2??6ú╖)ⁿ┼gEhW3RS⌠!a?┬╘├╢-ß?·▄╔B,_?╟│┤'C║j«?ΩcqJ╣²▀÷±?0s∩░uτ8Φ½&Σ¬y▓H?*?AL?═eDX??≥╚╧
4σ+r=Ñ¼╙U▌"?.⌐?≡K?k╥áF\?╕QΘ?╪Z?▐√╠?`M?7▒°G^≈@xz?>t:╦╨íw¿─┐]Io(V╡?P¡┴?º┌ΓO┘φ└╓~|#⌡π?}µ
╗l???$ó{n/╫mi╤<9f≤?∙»Nª;?1??εT?■╩%╒╛[╜p∞α╬vñ╞bYδ╝5█


ctrl and extended filtered out:

?d26)gEhW3RS!a-B,_'CjcqJ0su8&yH*ALeDX4+r=U".KkF
\QZ`M7G^@xz>t:w]Io(VPO~|#}l${n/mi<9fN;1T%[pvbY5

Unicode: Using Regular Expressions

<lang Scala>// // A Unicode test string // val ulist = 0x8232.toChar :: 0xFFF9.toChar :: 0x200E.toChar :: (1.toChar to 2000.toChar).toList val ustring = scala.util.Random.shuffle( ulist ).mkString

// Remove control codes including private codes val sNoCtrlCode = ustring.replaceAll("[\\p{C}]","")

val htmlNoCtrlCode = for( i <- sNoCtrlCode.indices ) yield

 "&#" + sNoCtrlCode(i).toInt + ";" + (if( (i+1) % 10 == 0 ) "\n" else "")

println( "ctrl filtered out:

\n\n" + htmlNoCtrlCode.mkString + "

\n" )

// Keep 0x00-0x7f and remove control codes val sNoExtCode = ustring.replaceAll("[^\\p{InBasicLatin}]","").replaceAll("[\\p{C}]","")

val htmlNoExtCode = for( i <- sNoExtCode.indices ) yield

 "&#" + sNoExtCode(i).toInt + ";" + (if( (i+1) % 10 == 0 ) "\n" else "")

println( "ctrl and extended filtered out:

\n\n" + htmlNoExtCode.mkString + "

\n" )</lang>

Output:

ctrl filtered out:

Қ۳ҹؽݠČǗ ɄخȿѻȺ·˖ҎDװѩԸץ˶٤ǞĽۭԑϣʱƁΫیոϐۛؕƟͱӄצ
ݞÄҺϤΪq͆ݶȲֆ֫՞ѡ٘ٺ݅ݦϠ۸ܞЕ²ɋډҒӂȏϘʚΧ˾ܡȳևՋƖדȇހڷ
ӣ؊ՙ̨۟ۀĦ¬ς݇؛ĿΟՕƜ1ԵۣݬͮǄ̪عڔЊڳœӟѺ՜ʬΚ݀͗׵̾ʊáǇѪ
ٹȭםޮɅ֜ʼݥޤڎۊ΂ŭЁ˹īʶñۼ[׈ӽه:3ŜSԛģó͑؝Јי̅ݏˬˮіۍ
PԅM׷ѯԶɔܺ֘ݷԾڽˎΞn̏ŗۧ˒ޥϷǅŀ˳Ѡ̮ݕũۃɹƾފѼܚٍڢŽܛńի
߀CžʾʹքӭξҖҢǘZ<ɼÐՅ̔ݧئ٫ʖѬ̩ߌǿɇݻ÷ђΤǀёՓJѦϻΥ¨̦ڥ
ˍ͖٭зݡѧס̶̵¯ȐƌޭԮϙҦ+ڦÇ֍ɽƥЦ۩ǦҠêʧɮð̣̯ޘƭƠͺޠ׺ݩγ
ѳ֊НۜÚӺϭ̃ݵƬŇЎٛԪճɟЩЋֱϜޒfޓʨ؄ܮɱղŬέǏu։Ҹ˅رɾʘ׶ͅ
߃¾ª"ɖȾύƔýՈԉգȨڼۮ͍õŘ]àߊܱЫҴٗԞۢ ˂ہƞ׻ɺƚ۞ҤڻƸǵǯ
܄ʠƲťïܠmТϋɥΈώͶ٢ؖټ\Ŵˣé֔ڤÿϛσ߂Λøʞӿăմ؉ϪЗպƓ҆܀ݰ
ѹΏɨғڲƀɞԗ26Ĕŵ³ѥ͛ǨՄǓĻ֌ڊʝӹʍ̠ϰ͸ʄՍə܅лġޏǌ˴ʃ۵Ϻǆ
՟Ҽ̈۹ԺߎМރѵ͋ؾЇѐ|ԨةݝɕǕڴǉȩþؐ؆׉j˿ق۽ɳОѷęĳٯÂě޳ȴ
˓חګ٠ޅךćءɉӢɗчЉő͜Ѐ֨ےϸܽԀ»эјۇޣ֤Ґ͊ȫއɒۓ۷́ضӖΙَБ
×ʳҧЅȗUƅŷÈɸȕ܆ĵޖȁɢӼԒѢխǖ@ǡȰ՘޵ўҍГӛº۾ף˔ъͣʏ«ћڏ
حǟΖԕƑǼթٸe֦ʗސڍƙКԻ̿ιü̧´փϱʤܭηƷѨЮԭѿ¢ßݚؒ٪ҩʢں`
۠μưɍӉØN̬ވƘȈ֎ǝٙӷΨи¥՗еοݫ̷Ɨ?ͰĹ֝ݸ_؇Àׁ̌ûʥĭȶǍԔ
үơ̕ג׸˗ϑӤ׼Ӱ'άܶѮĀشڱӻǻܼƿ܉ͪ޽Ѱܑ̓K~Ұ֮πҬʷ˫ۯٿpВ̥
տؓЍܒ˲ӥɰާڜԫ͎ϿűӈϦƤڣʓƎѱޛяâޱƻЄÃ̸ـ̂֕Ӛ̗֣ͬӦ݄ۑƦܖ
߄ɷۉڨȑձІȖƯŮµۡуħۦِ̱ԢɑФ׾١̺دʂsչ.ۋҾėè˭ٷbϮݱݔǩʈ
ȻiͫϯԦĚػţ܍׭եֿχ޺݂ت܁լɀгޙȥŉˈՇݣ̰ӊɩɲȢәǊȬ֙׀ݼŏكЭ
ʒױ̼љфȃHՖ؟҂̢ʕʲƼްӀŁڄ޸˼ȅԙÙ7ّſۘ٩ȱ֟ƕ͕ʆŚͼօ°؈>ݺ
...


ctrl and extended filtered out:

 Dq1[:3SPMnCZ<J+fu"]m\26|jU@e`N?_'K~ps.biH7>zAXVF5
=OgBhYGc-4)E/*a,%wTLoR&W{kd}8l^;0#(!trvIx$Qy9

Seed7

Seed7 strings are UTF-32 encoded, therefore no destinction between BYTE and Unicode strings is necessary. The example below uses STD_UTF8_OUT from the library utf8.s7i, to write Unicode characters with UTF-8 encoding to the console.

<lang seed7>$ include "seed7_05.s7i";

 include "utf8.s7i";

const func string: stripControl (in string: stri) is func

 result
   var string: stripped is "";
 local
   var integer: old_pos is 1;
   var integer: index is 0;
   var char: ch is ' ';
 begin
   for ch key index range stri do
     if ch < ' ' or ch = '\127;' then
       stripped &:= stri[old_pos .. pred(index)];
       old_pos := succ(index);
     end if;
   end for;
   stripped &:= stri[old_pos ..];
 end func;

const func string: stripControlAndExtended (in string: stri) is func

 result
   var string: stripped is "";
 local
   var integer: old_pos is 1;
   var integer: index is 0;
   var char: ch is ' ';
 begin
   for ch key index range stri do
     if ch < ' ' or ch >= '\127;' then
       stripped &:= stri[old_pos .. pred(index)];
       old_pos := succ(index);
     end if;
   end for;
   stripped &:= stri[old_pos ..];
 end func;

const string: src is "déjà vu\ # Unicode

   \\n\0;\31; \33;\126;\127;\128;\255;\n\  # Various boundary cases
   \as⃝df̅";                                 # Unicode combining characters

const proc: main is func

 begin
   OUT := STD_UTF8_OUT;
   writeln("source text:");
   writeln(src);
   writeln("Stripped of control codes:");
   writeln(stripControl(src));
   writeln("Stripped of control codes and extended characters:");
   writeln(stripControlAndExtended(src));
 end func;</lang>

Output:

source text:
déjà vu
� !~?ÿ
as⃝df̅
Stripped of control codes:
déjà vu !~ÿas⃝df̅
Stripped of control codes and extended characters:
dj vu !~asdf

Sidef

<lang ruby>var str = "\ba\x00b\n\rc\fd\xc3\x7ffoo"

var letters = str.chars.map{.ord} say letters.map{.chr}.join.dump

var nocontrols = letters.grep{ (_ > 32) && (_ != 127) } say nocontrols.map{.chr}.join.dump

var noextended = nocontrols.grep{ _ < 127 } say noextended.map{.chr}.join.dump</lang>

Output:

"\ba\0b\n\rc\fd\xC3\x7Ffoo"
"abcd\xC3foo"
"abcdfoo"

Tcl

<lang tcl>proc stripAsciiCC str {

   regsub -all {[\u0000-\u001f\u007f]+} $str ""

} proc stripCC str {

   regsub -all {[^\u0020-\u007e]+} $str ""

}</lang>

TI-83 BASIC

TI-83 BASIC doesn't support ASCII or Unicode, so the following program just strips every character that doesn't have a corresponding glyph from 32 to 126 decimal in a real ASCII table.

The following "normal characters" do exist, but can't be typed on the calculator and a hex editor must be used to enter them:

<lang ti83b>#$&@;_`abcdefghijklmnopqrstuvwxyz|~</lang>

The double quote character (ASCII decimal 34) can be entered, but cannot be escaped and thus cannot be stored to strings without the use of hex editors. The following program will remove double quotes from the input string if they were hacked in simply because having one stored to the "check" string is syntactically invalid.

So, in sum, you have to hack the calculator to enter in this program, but once it's entered you can transfer it to unhacked calculators and it will work.

<lang ti83b>:" !#$%&'()*+,-./0123456789:;<=>?ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~"→Str0

Input ">",Str1

":"+Str1+":"→Str1

For(I,2,length(Str1)-2)

If not(inString(Str0,sub(Str1,I,1)))

sub(Str1,1,I-1)+sub(Str1,I+1,length(Str1)-(I+1))→Str1

End

sub(Str1,2,length(Str1)-1)→Str1

Pause Str1</lang>

TXR

Translation of: Racket

<lang txrlisp>(defun strip-controls (str)

(regsub #/[\x0-\x1F\x7F]+/ "" str))

(defun strip-controls-and-extended (str)

 (regsub #/[^\x20-\x7F]+/ "" str))</lang>

VBScript

Derived from the BASIC version. <lang vb> Function StripCtrlCodes(s) tmp = "" For i = 1 To Len(s) n = Asc(Mid(s,i,1)) If (n >= 32 And n <= 126) Or n >=128 Then tmp = tmp & Mid(s,i,1) End If Next StripCtrlCodes = tmp End Function

Function StripCtrlCodesExtChrs(s) tmp = "" For i = 1 To Len(s) n = Asc(Mid(s,i,1)) If n >= 32 And n <= 126 Then tmp = tmp & Mid(s,i,1) End If Next StripCtrlCodesExtChrs = tmp End Function

WScript.StdOut.Write "ab�cd�ef�gh?€" & " = " & StripCtrlCodes("ab�cd�ef�gh?€") WScript.StdOut.WriteLine WScript.StdOut.Write "ab�cd�ef�gh?ij†klð€" & " = " & StripCtrlCodesExtChrs("ab�cd�ef�gh?ij†klð€") WScript.StdOut.WriteLine </lang>

Output:

ab�cd�ef�gh?€ = abcdefgh€
ab�cd�ef�gh?ij†klð€ = abcdefghijkl

XPL0

<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations string 0; \use zero-terminated string convention

proc Strip(Str, Both); \Strip out control and optionally extended chars char Str; int Both; int I, J, C; [I:= 0; while Str(I) do

   [C:= Str(I);
   if Both then C:= extend(C); \if stripping extended chars too, extend sign
   if C<$20 or C=$7F then
       [J:= I;                 \eliminate char by shifting string down over it
       repeat  C:= Str(J+1);
               Str(J):= C;
               J:= J+1;
       until   C=0;
       ]
   else I:= I+1;
   ];

];

char String; [String:= "Hello^M^J World àáâã"; Text(0, String); CrLf(0); Strip(String, false); Text(0, String); CrLf(0); Strip(String, true); Text(0, String); CrLf(0); ]</lang>

Output:

Hello
 World àáâã
Hello World àáâã
Hello World

zkl

ASCII <lang zkl>var ctlCodes=([1..31].pump(String,"toChar") +(127).toChar()); var extdChars=[127..255].pump(String,"toChar");

var test = "string of ☺☻♥♦⌂, control characters(\t\b\e) and other ilk.♫☼§►↔◄"; test.println("<< test string"); (test-ctlCodes).println("<< no control chars"); (test-extdChars).println("<< no extended chars"); (test-extdChars-ctlCodes).println("<< text"); </lang>

Output:

string of ☺☻♥♦⌂, control characters(   and other ilk.♫☼§►↔◄<< test string
string of ☺☻♥♦⌂, control characters() and other ilk.♫☼§►↔◄<< no control chars
string of , control characters(and other ilk.<< no extended chars
string of , control characters() and other ilk.<< text