The HasControlCharacter( s ) command determines whether s contains a control character.

If s contains a control character, HasControlCharacter returns true. Otherwise, false is returned.

Note: A control character is a special non-printing character that is defined by the character set to which it belongs. For more information about control characters in Maple, see backslash.

All of the StringTools package commands treat strings as (null-terminated) sequences of $8$-bit (ASCII) characters.  Thus, there is no support for multibyte character encodings, such as unicode encodings.

The StringTools[HasControlCharacter] command is thread-safe as of Maple 15.

For more information on thread safety, see index/threadsafe.

$\mathrm{with}\left(\mathrm{StringTools}\right)\:$

$s≔\mathrm{convert}\left(\left[\mathrm{`\$`}\left(1..255\right)\right]\,'\mathrm{bytes}'\right)\:$

$\mathrm{length}\left(s\right)$

$255$

$\mathrm{HasControlCharacter}\left(s\right)$

$\mathrm{true}$