Chapter Contents |
Previous |
Next |
iscntrl |
Portability: | ISO/ANSI C conforming, UNIX compatible |
SYNOPSIS | |
DESCRIPTION | |
RETURN VALUE | |
CAUTION | |
PORTABILITY | |
IMPLEMENTATION | |
EXAMPLE | |
RELATED FUNCTIONS | |
SEE ALSO |
SYNOPSIS |
#include <ctype.h> int iscntrl(int c);
DESCRIPTION |
iscntrl
tests an integer value
c
to determine whether
it is a control character.
RETURN VALUE |
iscntrl
returns 0 if the character is not a control character, or a nonzero value
if it is. If the argument is
EOF
, 0 is
returned.
CAUTION |
The effect of
iscntrl
on a noncharacter argument other than
EOF
is undefined. Do not assume that
iscntrl
returns either 0 or
1.
Note:
For some EBCDIC
characters, neither
iscntrl(c)
nor
isprint(c)
is true, even though this identity
is sometimes used as a definition of
isprint
.
PORTABILITY |
You should carefully examine the
iscntrl
function when using it in a program that
is expected to be portable. IBM uses the words control character
to designate characters between
0x00
and
0x3f
, as well as
0xff
. This implementation defines
iscntrl('\xff')
as false.
IMPLEMENTATION |
iscntrl
is implemented by a macro.
iscntrl
tests
a character to see whether it is less than a blank in the EBCDIC collating
sequence. This is true for the EBCDIC equivalents of all ASCII control characters.
EXAMPLE |
#include <ctype.h> #include <stdio.h> main() { char *buf; buf = "Hello World. \n This is a test. "; do { if (!iscntrl(*buf)) putchar(*buf); else putchar('*'); buf++; } while (*buf); putchar("\n"); }
RELATED FUNCTIONS |
SEE ALSO |
Chapter Contents |
Previous |
Next |
Top of Page |
Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.