freebsd man page for iscntrl

ISCNTRL(3)						   BSD Library Functions Manual 						ISCNTRL(3)

NAME
     iscntrl -- control character test

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <ctype.h>

     int
     iscntrl(int c);

     int
     iscntrl_l(int c, locale_t loc);

DESCRIPTION
     The iscntrl() function tests for any control character.  The value of the argument must be 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_l() function takes an explicit locale argument, whereas the iscntrl() function uses the current global or per-thread locale.

RETURN VALUES
     The iscntrl() function returns zero if the character tests false and returns non-zero if the character tests true.

COMPATIBILITY
     The 4.4BSD extension of accepting arguments outside of the range of the unsigned char type in locales with large character sets is considered
     obsolete and may not be supported in future releases.  The iswcntrl() function should be used instead.

SEE ALSO
     ctype(3), iswcntrl(3), xlocale(3), ascii(7)

STANDARDS
     The iscntrl() function conforms to ISO/IEC 9899:1990 (``ISO C90'').  The iscntrl_l() function conforms to IEEE Std 1003.1-2008 (``POSIX.1'').

BSD
								   July 17, 2005							       BSD