Manual page for CTYPE(3P)
isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, toupper, tolower - character classification macros
SYNOPSIS
#include <ctype.h>
isalpha(int c);
. . .
DESCRIPTION
These interfaces classify C locale integer values
by table lookup.
Each is a predicate returning nonzero for true,
zero for false.
- isalpha
-
c
is a letter
- isupper
-
c
is an upper case letter
- islower
-
c
is a lower case letter
- isdigit
-
c
is a digit
- isxdigit
-
c
is a hex digit
- isalnum
-
c
is any character for which isalpha or isdigit is true.
- isspace
-
c
is a space, tab, carriage return, newline, vertical tab, or formfeed
- ispunct
-
c
is a punctuation character (neither control nor alphanumeric)
- isprint
-
c
is a printing character, code 040(8) (space) through 0176 (tilde)
- isgraph
-
c
is a printing character, similar to
isprint
except false for space.
- iscntrl
-
c
is a delete character (0177) or ordinary control character
(less than 040).
- tolower
-
c
is converted to lower case. Return value is undefined if not
isupper(c).
- toupper
-
c
is converted to upper case. Return value is undefined if not
islower(c).
NOTE
These interfaces are provided in the form of macros and functions.
If you're using NEXTSTEP font encoding, then
you shouldn't use these interfaces;
use the NXCType functions instead.
NXCType is discussed in the online NEXTSTEP documentation
(accessible through the Digital Librarian).
These macros are provided to support ANSI-C.
SEE ALSO
ascii(7), online NEXTSTEP documentation for NXCType
Created by unroff & hp-tools.
© somebody (See intro for details). All Rights Reserved.
Last modified 11/5/97
