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StringTools

 IsControlCharacter
 determine if a character is a control character

 Calling Sequence IsControlCharacter(char)

Parameters

 char - string; character to test

Description

 • The IsControlCharacter(char) command determines whether char is a control character.
 If char is a control character, IsControlCharacter 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.
 • If char is a string that contains more than one character, then all the characters in the string are tested. The command returns true if the condition is true of all characters in the input string. For the empty string, the tested condition is vacuously true.
 • 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[IsControlCharacter] command is thread-safe as of Maple 15.

Examples

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

Important Note: The user should take care if attempting to copy the following example into a Maple session.  Since the output from the following command contains control characters, unexpected results can occur on certain platforms. It is recommended that this example not be copied.

 > $\mathrm{Select}\left(\mathrm{IsControlCharacter},s\right)$
 ${"\a\b\t\n\v\f\r\e"}$ (2)