xref: /dragonfly/lib/libc/locale/iscntrl.3 (revision c66c7e2f)

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.\"     @(#)iscntrl.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: head/lib/libc/locale/iscntrl.3 233992 2012-04-07 09:05:30Z joel $
.\"
.Dd December 25, 2013
.Dt ISCNTRL 3
.Os
.Sh NAME
.Nm iscntrl ,
.Nm iscntrl_l
.Nd control character test
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ctype.h
.Ft int
.Fn iscntrl "int c"
.Ft int
.Fn iscntrl_l "int c" "locale_t locale"
.Sh DESCRIPTION
The
.Fn iscntrl
and
.Fn iscntrl_l
functions test for any control character.
The value of the argument must be representable as an
.Vt "unsigned char"
or the value of
.Dv EOF .
.Pp
In the ASCII character set, this includes the following characters
(with their numeric values shown in octal):
.Bl -column \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__ \&000_``0''__
.It "\&000\ NUL" Ta "001\ SOH" Ta "002\ STX" Ta "003\ ETX" Ta "004\ EOT"
.It "\&005\ ENQ" Ta "006\ ACK" Ta "007\ BEL" Ta "010\ BS" Ta "011\ HT"
.It "\&012\ NL" Ta "013\ VT" Ta "014\ NP" Ta "015\ CR" Ta "016\ SO"
.It "\&017\ SI" Ta "020\ DLE" Ta "021\ DC1" Ta "022\ DC2" Ta "023\ DC3"
.It "\&024\ DC4" Ta "025\ NAK" Ta "026\ SYN" Ta "027\ ETB" Ta "030\ CAN"
.It "\&031\ EM" Ta "032\ SUB" Ta "033\ ESC" Ta "034\ FS" Ta "035\ GS"
.It "\&036\ RS" Ta "037\ US" Ta "177\ DEL" Ta \& Ta \&
.El
.Pp
The
.Fn iscntrl_l
function takes an explicit
.Fa locale
argument, whereas the
.Fn iscntrl
function uses the current global or per-thread locale.
.Sh RETURN VALUES
The
.Fn iscntrl
and
.Fn iscntrl_l
functions return zero if the character tests false and
returns non-zero if the character tests true.
.Sh COMPATIBILITY
The
.Bx 4.4
extension of accepting arguments outside of the range of the
.Vt "unsigned char"
type in locales with large character sets is considered obsolete
and may not be supported in future releases.
The
.Fn iswcntrl
and
.Fn iswcntrl_l
functions should be used instead.
.Sh SEE ALSO
.Xr ctype 3 ,
.Xr ctype_l 3 ,
.Xr iswcntrl 3 ,
.Xr iswcntrl_l 3 ,
.Xr xlocale 3 ,
.Xr ascii 7
.Sh STANDARDS
The
.Fn iscntrl
function conforms to
.St -isoC .
The
.Fn iscntrl_l
function conforms to
.St -p1003.1-2008 .