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Command: iscntrl | Section: 3 | Source: OpenBSD | File: iscntrl.3
ISCNTRL(3) FreeBSD Library Functions Manual ISCNTRL(3)
NAME
iscntrl, iscntrl_l - control single-byte character test
SYNOPSIS
#include <ctype.h>
int
iscntrl(int c);
int
iscntrl_l(int c, locale_t locale);
DESCRIPTION
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.
RETURN VALUES
These functions return zero if the character tests false or non-zero if
the character tests true.
ENVIRONMENT
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).
SEE ALSO
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)
STANDARDS
The iscntrl() function conforms to ANSI X3.159-1989 ("ANSI C89"), and
iscntrl_l() to IEEE Std 1003.1-2008 ("POSIX.1").
HISTORY
The iscntrl() function first appeared in Version 7 AT&T UNIX, and
iscntrl_l() has been available since OpenBSD 6.2.
CAVEATS
The argument c must be EOF or representable as an unsigned char;
otherwise, the result is undefined.
FreeBSD 14.1-RELEASE-p8 September 11, 2022 FreeBSD 14.1-RELEASE-p8