| |
| /* |
| FUNCTION |
| <<iscntrl>>---control character predicate |
| |
| INDEX |
| iscntrl |
| |
| ANSI_SYNOPSIS |
| #include <ctype.h> |
| int iscntrl(int <[c]>); |
| |
| TRAD_SYNOPSIS |
| #include <ctype.h> |
| int iscntrl(<[c]>); |
| |
| DESCRIPTION |
| <<iscntrl>> is a macro which classifies ASCII integer values by table |
| lookup. It is a predicate returning non-zero for control characters, and 0 |
| for other characters. 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 iscntrl>>'. |
| |
| RETURNS |
| <<iscntrl>> returns non-zero if <[c]> is a delete character or ordinary |
| control character (<<0x7F>> or <<0x00>>--<<0x1F>>). |
| |
| PORTABILITY |
| <<iscntrl>> is ANSI C. |
| |
| No supporting OS subroutines are required. |
| */ |
| |
| #include <_ansi.h> |
| #include <ctype.h> |
| |
| |
| |
| #undef iscntrl |
| int |
| _DEFUN(iscntrl,(c),int c) |
| { |
| return(__ctype_ptr__[c+1] & _C); |
| } |
| |
| |
