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/*

FUNCTION

        <<isalpha>>---alphabetic character predicate

INDEX

        isalpha

ANSI_SYNOPSIS

        #include <ctype.h>

        int isalpha(int <[c]>);

TRAD_SYNOPSIS

        #include <ctype.h>

        int isalpha(<[c]>);

DESCRIPTION

<<isalpha>> is a macro which classifies ASCII integer values by table

lookup.  It is a predicate returning non-zero when <[c]> represents an

alphabetic ASCII character, and 0 otherwise.  It is defined only when

<<isascii>>(<[c]>) is true or <[c]> is EOF.

You can use a compiled subroutine instead of the macro definition by

undefining the macro using `<<#undef isalpha>>'.

RETURNS

<<isalpha>> returns non-zero if <[c]> is a letter (<<A>>--<<Z>> or

<<a>>--<<z>>).

PORTABILITY

<<isalpha>> is ANSI C.

No supporting OS subroutines are required.

*/

#include <_ansi.h>

#include <ctype.h>

#undef isalpha

int

_DEFUN(isalpha,(c),int c)

{

        return((_ctype_ + 1)[c] & (_U|_L));

}