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/*

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 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 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);

}