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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);

DESCRIPTION
     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 char-acter character
     acter set, this includes the following characters (preceded by their numeric values, 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

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), isalnum_l(3), iswcntrl(3), multibyte(3), ascii(7)

STANDARDS
     The iscntrl() function conforms to ISO/IEC 9899:1990 (``ISO C90'').

BSD                             August 21, 2004                            BSD