SQL below gives you list of chr values between 0 to 255
select level,CHR(level),
decode(chr(level), regexp_substr(chr(level), '[[:graph:]]'), '*') is_graph, --printable character
decode(chr(level), regexp_substr(chr(level), '[[:blank:]]'), '*') is_blank,
decode(chr(level), regexp_substr(chr(level), '[[:alnum:]]'), '*') is_alnum, --Any alphanumeric character, [A-Za-z0-9]
decode(chr(level), regexp_substr(chr(level), '[[:alpha:]]'), '*') is_alpha, -- Any letter, [A-Za-z]
decode(chr(level), regexp_substr(chr(level), '[[:digit:]]'), '*') is_digit, -- Any digit, [0-9]
decode(chr(level), regexp_substr(chr(level), '[[:cntrl:]]'), '*')
is_cntrl, --Any character not part of the character classes: [:upper:],
[:lower:], [:alpha:], [:digit:], [:punct:], [:graph:], [:print:],
[:xdigit:]
decode(chr(level), regexp_substr(chr(level), '[[:lower:]]'), '*') is_lower, -- Any lowercase letter, [a-z]
decode(chr(level), regexp_substr(chr(level), '[[:upper:]]'), '*') is_upper, --Any uppercase letter, [A-Z]
decode(chr(level), regexp_substr(chr(level), '[[:print:]]'), '*') is_print, --Any printable character
decode(chr(level), regexp_substr(chr(level), '[[:punct:]]'), '*')
is_punct, --Any punctuation character: START ! ' # S % & ' ( ) * + ,
- . / : ; < = > ? @ [ / ] ^ _ { | } ~ END
decode(chr(level), regexp_substr(chr(level), '[[:space:]]'), '*')
is_space, --A tab, new line, vertical tab, form feed, carriage return,
or space
decode(chr(level), regexp_substr(chr(level), '[[:xdigit:]]'), '*') is_xdigit --Any hexadecimal digit, [0-9A-Fa-f]
from dual
where level between 0 and 255
connect by level <= 256
