.\" @(#)ctype.3 6.4 (Berkeley) 5/12/86

.\"

.TH CTYPE 3 "May 12, 1986"

.AT 3

.SH NAME

ctype, isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii, toupper, tolower, toascii \- character classification macros

.SH SYNOPSIS

.nf

.ft B

#include <ctype.h>

int isalpha(int \fIc\fP)

\&...

.fi

.SH DESCRIPTION

These macros classify characters

by table lookup.

Each is a predicate returning nonzero for true,

zero for false.

.B Isascii

and

.B toascii

are defined on all integer values; the rest

are defined only on the range of

.B "unsigned char"

and on the special value

EOF (see

.BR stdio (3)).

.TP 15n

.B isalpha

.I c

is a letter

.TP

.B isupper

.I c

is an upper case letter

.TP

.B islower

.I c

is a lower case letter

.TP

.B isdigit

.I c

is a digit

.TP

.B isxdigit

.I c

is a hex digit

.TP

.B isalnum

.I c

is an alphanumeric character

.TP

.B isspace

.I c

is a space, tab, carriage return, newline, vertical tab, or formfeed

.TP

.B ispunct

.I c

is a punctuation character (neither control nor alphanumeric)

.TP

.B isprint

.I c

is a printing character, code 040(8) (space) through 0176 (tilde)

.TP

.B isgraph

.I c

is a printing character, similar to

.B isprint

except false for space.

.TP

.B iscntrl

.I c

is a delete character (0177) or ordinary control character

(less than 040).

.TP

.B isascii

.I c

is an ASCII character, code less than 0200

.TP

.B tolower

.I c

is converted to lower case. Return value is undefined if not

.BR isupper (\fIc\fR).

.TP

.B toupper

.I c

is converted to upper case. Return value is undefined if not

.BR islower (\fIc\fR).

.TP

.B toascii

.I c

is converted to be a valid ascii character.

.SH "SEE ALSO"

.BR ascii (7)