ISALPHA(3)

ISALPHA(3) | Library Functions Manual | ISALPHA(3)

# 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.

April 17, 2008 | NetBSD 8.3