NAME
isalnum —
alphanumeric character
test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
isalnum(
int
c);
DESCRIPTION
The
isalnum() function tests for any character for which
isalpha(3) or
isdigit(3) is true.
RETURN VALUES
The
isalnum() function returns zero if the character tests
false and returns non-zero if the character tests true.
SEE ALSO
ctype(3),
isalpha(3),
isascii(3),
isblank(3),
iscntrl(3),
isdigit(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
isalnum() function conforms to
ANSI
X3.159-1989 (“ANSI C89”).
CAVEATS
The argument to
isalnum() must be
EOF
or representable as an
unsigned char; otherwise, the
behavior is undefined. See the
CAVEATS
section of
ctype(3) for more
details.