@ISPRINT[string]: Returns 1 if string is entirely composed of printable characters; 0 otherwise.
See also: @ISALNUM, @ISALPHA, @ISASCII, @ISCNTRL, @ISDIGIT, @ISPUNCT, @ISSPACE, @ISXDIGIT.
Examples:
echo %@isprint[abc]
1
set var=abc^ndef
echo %@isprint[%var]
0