HP C/iX Library Reference Manual (30026-90004)

Chapter 5 217
HP C/iX Library Function Descriptions
iscntrl
iscntrl
Tests whether an argument is a control character.
Syntax
#include <ctype.h>
int iscntrl (int c );
Parameters
c An argument to be evaluated. The argument must be representable as an
unsigned char or the macro EOF.
Return Values
≠0 The argument passed in c is an ASCII control character.
0 The argument passed in
c is not an ASCII control character.
Description
The iscntrl function returns a nonzero value if the argument passed in c is an ASCII
control character (octal values 00 through 037 and 0177); otherwise, the returned value is
zero.
See Also
isalnum(), isalpha(), isdigit(), isgraph(), islower(), isprint(), ispunct(),
isspace(), isupper(), isxdigit(), ANSI C 4.3.1.3, POSIX.1 8.1