| /* |
| 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 if |
| <[c]> is representable as an unsigned char or if <[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_ptr__[c+1] & (_U|_L)); |
| } |
| |
