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NAME
iscntrl - test for a control character
SYNOPSIS
#include <ctype.h> int iscntrl(int c);
DESCRIPTION
The iscntrl() function shall test whether c is a character of class cntrl in the program's current
locale; see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale.
The c argument is a type int, the value of which the application shall ensure is a character
representable as an unsigned char or equal to the value of the macro EOF. If the argument has any other
value, the behavior is undefined.
RETURN VALUE
The iscntrl() function shall return non-zero if c is a control character; otherwise, it shall return 0.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
To ensure applications portability, especially across natural languages, only this function and those
listed in the SEE ALSO section should be used for character classification.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
isalnum() , isalpha() , isdigit() , isgraph() , islower() , isprint() , ispunct() , isspace() , isupper()
, isxdigit() , setlocale() , the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale,
<ctype.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The
original Standard can be obtained online at http://www.opengroup.org/unix/online.html .