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/*
FUNCTION
<<iscntrl>>, <<iscntrl_l>>---control character predicate
INDEX
iscntrl
INDEX
iscntrl_l
SYNOPSIS
#include <ctype.h>
int iscntrl(int <[c]>);
#include <ctype.h>
int iscntrl_l(int <[c]>, locale_t <[locale]>);
DESCRIPTION
<<iscntrl>> is a macro which classifies singlebyte charset 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.
<<iscntrl_l>> is like <<iscntrl>> but performs the check based on the
locale specified by the locale object locale. If <[locale]> is
LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
You can use a compiled subroutine instead of the macro definition by
undefining the macro using `<<#undef iscntrl>>' or `<<#undef iscntrl_l>>'.
RETURNS
<<iscntrl>>, <<iscntrl_l>> return non-zero if <[c]> is a delete character
or ordinary control character.
PORTABILITY
<<iscntrl>> is ANSI C.
<<iscntrl_l>> is POSIX-1.2008.
No supporting OS subroutines are required.
*/
#include <_ansi.h>
#include <ctype.h>
#undef iscntrl
int
iscntrl (int c)
{
return(__CTYPE_PTR[c+1] & _C);
}
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