NAME
isalpha —
alphabetic character
test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
isalpha(
int
c);
DESCRIPTION
The
isalpha() function tests for any character for which
isupper(3) or
islower(3) is true and for
which none of
iscntrl(3),
isdigit(3),
ispunct(3), or
isspace(3) is true. In the
``C'' locale,
isalpha() returns true only
for the characters for which
isupper(3) or
islower(3) is true.
RETURN VALUES
The
isalpha() function returns zero if the character tests
false and returns non-zero if the character tests true.
SEE ALSO
ctype(3),
isalnum(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
isalpha() function conforms to
ANSI
X3.159-1989 (“ANSI C89”).
CAVEATS
The argument to
isalpha() must be
EOF
or representable as an
unsigned char; otherwise, the
behavior is undefined. See the
CAVEATS
section of
ctype(3) for more
details.