ISDIGIT(3)
Library Functions Manual
ISDIGIT(3)
NAME
isdigit
—
decimal-digit character test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <
ctype.h
>
int
isdigit
(
int c
);
DESCRIPTION
The
isdigit
() function tests for any decimal-digit character.
RETURN VALUES
The
isdigit
() function returns zero if the character tests false and returns non-zero if the character tests true.
SEE ALSO
ctype(3)
,
isalnum(3)
,
isalpha(3)
,
isascii(3)
,
isblank(3)
,
iscntrl(3)
,
isgraph(3)
,
islower(3)
,
isprint(3)
,
ispunct(3)
,
isspace(3)
,
isupper(3)
,
isxdigit(3)
,
stdio(3)
,
toascii(3)
,
tolower(3)
,
toupper(3)
,
ascii(7)
STANDARDS
The
isdigit
() function conforms to ANSI X3.159-1989 (“ANSI C”).
CAVEATS
The argument to
isdigit
() must be
EOF
or representable as an
unsigned char
; otherwise, the behavior is undefined. See the
CAVEATS
section of
ctype(3)
for more details.
April 17, 2008
NetBSD 5.99