ISCNTRL(3) | Library Functions Manual | ISCNTRL(3) |
iscntrl
, iscntrl_l
— control single-byte character test
#include
<ctype.h>
int
iscntrl
(int
c);
int
iscntrl_l
(int
c, locale_t
locale);
The
iscntrl
()
and
iscntrl_l
()
functions tests for any control character.
In the C locale, the complete list of control characters consists of the characters numbered 0x00–0x1f and 0x7f. OpenBSD always uses the C locale for these functions, ignoring the global locale, the thread-specific locale, and the locale argument.
These functions return zero if the character tests false or non-zero if the character tests true.
On systems supporting non-ASCII single-byte character encodings,
results of these functions may differ, and the results of
iscntrl
() may depend on the
LC_CTYPE
locale(1).
isalnum(3), isalpha(3), isascii(3), isblank(3), isdigit(3), isgraph(3), islower(3), isprint(3), ispunct(3), isspace(3), isupper(3), iswcntrl(3), isxdigit(3), stdio(3), toascii(3), tolower(3), toupper(3), ascii(7)
The iscntrl
() function conforms to
ANSI X3.159-1989 (“ANSI C89”),
and iscntrl_l
() to IEEE Std
1003.1-2008 (“POSIX.1”).
The iscntrl
() function first appeared in
Version 7 AT&T UNIX, and
iscntrl_l
() has been available since
OpenBSD 6.2.
The argument c must be
EOF
or representable as an unsigned
char
; otherwise, the result is undefined.
October 4, 2017 | OpenBSD-current |