ISCNTRL(3) Library Functions Manual ISCNTRL(3)
NAME
iscntrlcontrol character test
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ctype.h>
int
iscntrl(int c);
DESCRIPTION
The iscntrl() function tests for any control character.
RETURN VALUES
The iscntrl() function returns zero if the character tests false and returns non-zero if the character tests true.
SEE ALSO
STANDARDS
The iscntrl() function conforms to ANSI X3.159-1989 (“ANSI C”).
CAVEATS
The argument to iscntrl() must be EOF or representable as an unsigned char; otherwise, the behavior is undefined. See the CAVEATS section of ctype(3) for more details.