NAME
isalpha —
alphabetic character test
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
isalpha(int
c);
DESCRIPTION
Theisalpha()
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.