cpp/string/byte/isprint

Checks if is a printable character as classified by the currently installed C locale. In the default, locale, the following characters are printable:


 * digits
 * uppercase letters
 * lowercase letters
 * punctuation characters
 * space

The behavior is undefined if the value of is not representable as  and is not equal to.

Return value
Non-zero value if the character can be printed, zero otherwise.