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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 and greater than 126. 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.

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>

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-

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>

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 (

   "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)

}

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, "\n")
   fmt.Println("as bytes, stripped of control codes:")
   fmt.Println(stripCtlFromBytes(src), "\n")
   fmt.Println("as bytes, stripped of control codes and extended characters:")
   fmt.Println(stripCtlAndExtFromBytes(src), "\n")
   fmt.Println("as UTF-8, stripped of control codes:")
   fmt.Println(stripCtlFromUTF8(src), "\n")
   fmt.Println("as UTF-8, stripped of control codes and extended characters:")
   fmt.Println(stripCtlAndExtFromUTF8(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

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>

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>

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>

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

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>def stripped(x): return "".join([i for i in x if ord(i) in range(32, 127)])

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

REXX

version 1

This version is much faster, but much harder to understand what's happening. <lang rexx> /*REXX program to strip all "control codes" from a string (ASCII|EBCDIC)*/

xxx='string of ��?, may include control characters and other ilk.��' ebcdic=1=='f1'x /*is this an EBCDIC|ASCII system?*/

ccChars=xrange('0'x,d2c(c2d(' ')-1)) /*generate a range of characters.*/ if \ebcdic then ccChars=ccChars'7f'x /*add the ASCII '7f'X char. */

say 'hex ccChars =' c2x(ccChars)

yyy=translate(space(translate(xxx,'ff'x," "ccChars),0),,'ff'x) say 'old = >>>'xxx"<<<" say 'new = >>>'yyy"<<<" </lang> Output:

hex ccChars = 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F7F
old = >>>string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄<<<
new = >>>string of , may include control characters and other ilk.<<<

version 2

A slower version, but much easier to understand the process. <lang rexx> /*REXX program to strip all "control codes" from a string (ASCII|EBCDIC)*/

xxx='string of ☺☻♥♦⌂, may include control characters and other ilk.♫☼§►↔◄' ebcdic=1=='f1'x /*is this an EBCDIC|ASCII system?*/

ccChars=xrange('0'x,d2c(c2d(' ')-1)) /*generate a range of characters.*/ if \ebcdic then ccChars=ccChars'7f'x /*add the ASCII '7f'X char. */

say 'hex ccChars =' c2x(ccChars) yyy=

 do j=1 for length(xxx)
 _=substr(xxx,j,1)
 if pos(_,ccChars)\==0 then iterate   /*skip this char,  it's a no-no. */
 yyy=yyy||_
 end

say 'old = >>>'xxx"<<<" say 'new = >>>'yyy"<<<" </lang> Output is identical to version 1.

Ruby

<lang ruby>class String

 def strip_control_characters()
   self.chars.inject("") do |str, char|
     unless char.ascii_only? and (char.ord < 32 or char.ord == 127)
       str << char
     end
     str
   end
 end

 def strip_control_and_extended_characters()
   self.chars.inject("") do |str, char|
     if char.ascii_only? and char.ord.between?(32,126)
       str << char
     end
     str
   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>

outputs

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

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

Tcl

<lang tcl>proc stripAsciiCC str {

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

} proc stripCC str {

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

}</lang>