Problem Statement

Strip control codes and extended characters from a string.

The solution should demonstrate how to achieve each of the following results:

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.

Let's start with the solution:

BYTE FUNC IsAscii(CHAR c)
  IF c<32 OR c>124 OR c=96 OR c=123 THEN
    RETURN (0)
  FI
RETURN (1)

PROC Strip(CHAR ARRAY src,dst)
  CHAR c
  BYTE i

  dst(0)=0
  FOR i=1 TO src(0)
  DO
    c=src(i)
    IF IsAscii(c) THEN
      dst(0)==+1
      dst(dst(0))=c
    FI
  OD
RETURN

PROC Main()
  CHAR ARRAY
    src(20)=[16 0 16 96 123 'a 'b 'c 131 27 30 '1 '2 '3 4 1 20],
    dst(20)

  PrintF("Original string: ""%S""%E",src)
  Strip(src,dst)
  PrintF("Stripped string: ""%S""%E",dst)
RETURN