indigo. posix. ctype

Contains the basic POSIX interface for ASCII character classification.  The following entities are declared:

• isascii()
• isalpha()
• isupper()
• islower()
• isdigit()
• isxdigit()
• isspace()
• isctrnl()
• ispunct()
• isblank()
• isalnum()
• isgraph()
• isprint()
• toupper()
• tolower()