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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_ + 1)[c] & _C);
}
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