iscntrl - test for control character

Syntax

#include <ctype.h> int iscntrl(int c);

Description iscntrl() whether the character c is a control character. Control characters are

	non-printable characters, e.g. for printer control. In all cases, the argument c is an int, the value of which must be representable as an unsigned char or must equal the value of the macro EOF. If the argument c has any other value, the behavior is undefined.
Return val.	!= 0 0	Control character Not a control character
Notes	iscntrl() is implemented both as a function and as a macro. To generate a function call, the definition of the macro name must be first undefined (#undef iscntrl). The behavior of iscntrl() is determined by the class cntrl of the current locale. The current locale is the C locale, unless it was explicitly changed using setlocale().
See also	isalnum(), isalpha(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(), isxdigit(), setlocale(), ctype.h.