C in a Nutshell

Name

iscntrl

Synopsis

Ascertains whether a given character is a control character

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

The function iscntrl() tests whether its character argument is a control character. For the ASCII character set, these are the character codes from 0 through 31 and 127. The function may yield different results depending on the current locale setting for the localization category LC_CTYPE, which you can query or change using the setlocale() function.

If the argument is a control character, iscntrl() returns a nonzero value (that is, true); if not, the function returns 0 (false).

Example

See the example for isprint() in this chapter.

See Also

The corresponding C99 function for wide characters, iswcntrl(); isalnum(), isalpha(), isblank(), isdigit(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(), isxdigit(), setlocale()