iscntrl -- control character test
Standard C Library (libc, -lc)
#include <ctype.h>
int
iscntrl(int c);
The iscntrl() function tests for any control character. For single C
chars locales (see multibyte(3)) the value of the argument is representable
as an unsigned char or the value of EOF. In the ASCII character
set, this includes the following characters (with their numeric values
shown in octal):
000 NUL 001 SOH 002 STX 003 ETX 004 EOT
005 ENQ 006 ACK 007 BEL 010 BS 011 HT
012 NL 013 VT 014 NP 015 CR 016 SO
017 SI 020 DLE 021 DC1 022 DC2 023 DC3
024 DC4 025 NAK 026 SYN 027 ETB 030 CAN
031 EM 032 SUB 033 ESC 034 FS 035 GS
036 RS 037 US 177 DEL
The iscntrl() function returns zero if the character tests false and
returns non-zero if the character tests true.
Although iscntrl() accepts arguments outside of the range of the unsigned
char type in locales with large character sets, this is a 4.4BSD extension
and the iwcntrl() function should be used instead for maximum portability.
ctype(3), iswcntrl(3), multibyte(3), ascii(7)
The iscntrl() function conforms to ISO/IEC 9899:1990 (``ISO C89'').
FreeBSD 5.2.1 October 6, 2002 FreeBSD 5.2.1 [ Back ] |