3 isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii, toascii, _toupper, _tolower, toupper, tolower \- ASCII character classification
51 Each is a predicate returning nonzero for true,
54 is defined on all integer values; the rest
55 are defined only where
57 is true and on the single non-\c
66 is a letter, a\-z or A\-Z
70 is an upper case letter, A\-Z
74 is a lower case letter, a\-z
82 is a hexadecimal digit, 0\-9 or a\-f or A\-F
86 is an alphanumeric character, a\-z or A\-Z or 0\-9
90 is a space, horizontal tab, newline, vertical tab, formfeed, or carriage return
91 (0x20, 0x9, 0xA, 0xB, 0xC, 0xD)
95 is a punctuation character
98 !"#$%&'()*+,-./:;<=>?@[\e]^_`{|}~\fR)
102 is a printing character, 0x20 (space)
107 is a visible printing character, 0x21 (exclamation) through 0x7E
112 is a delete character, 0x7F,
113 or ordinary control character, 0x0 through 0x1F
119 character, 0x0 through 0x7F
122 is not a classification macro;
123 it converts its argument to
131 is an upper case letter,
133 returns the lower case version of the character;
134 otherwise it returns the original character.
136 is similar, returning the upper case version of a character
137 or the original character.
145 are corresponding macros which should only be used when it
146 is known that the argument is upper case or lower case, respectively.
148 .TF /sys/src/libc/port/ctype.c
150 .B /sys/include/ctype.h
153 .B /sys/src/libc/port/ctype.c