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Revision 1.21, Thu May 6 11:46:11 2010 UTC (4 years, 6 months ago) by jruoho
Branch: MAIN
CVS Tags: yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, netbsd-7-base, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-mips64-premerge-20101231, cherry-xenmp-base, cherry-xenmp, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver, HEAD
Changes since 1.20: +11 -6 lines

Note POSIX compliance. Reword a little around the example.

.\"	$NetBSD: ctype.3,v 1.21 2010/05/06 11:46:11 jruoho Exp $
.\"
.\" Copyright (c) 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)ctype.3	6.5 (Berkeley) 4/19/91
.\"
.Dd May 6, 2010
.Dt CTYPE 3
.Os
.Sh NAME
.Nm isalpha ,
.Nm isupper ,
.Nm islower ,
.Nm isdigit ,
.Nm isxdigit ,
.Nm isalnum ,
.Nm isspace ,
.Nm ispunct ,
.Nm isprint ,
.Nm isgraph ,
.Nm iscntrl ,
.Nm isblank ,
.Nm toupper ,
.Nm tolower ,
.Nd character classification and mapping functions
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In ctype.h
.Fn isalpha "int c"
.Fn isupper "int c"
.Fn islower "int c"
.Fn isdigit "int c"
.Fn isxdigit "int c"
.Fn isalnum "int c"
.Fn isspace "int c"
.Fn ispunct "int c"
.Fn isprint "int c"
.Fn isgraph "int c"
.Fn iscntrl "int c"
.Fn isblank "int c"
.Fn toupper "int c"
.Fn tolower "int c"
.Sh DESCRIPTION
The above functions perform character tests and conversions on the integer
.Ar c .
.Pp
See the specific manual pages for information about the
test or conversion performed by each function.
.Sh EXAMPLES
To print an upper-case version of a string to stdout,
the following code can be used:
.Bd -literal -offset indent
const char *s = "xyz";

while (*s != '\e0') {
    putchar(toupper((int)(unsigned char)*s));
    s++;
}
.Ed
.Sh SEE ALSO
.Xr isalnum 3 ,
.Xr isalpha 3 ,
.Xr isblank 3 ,
.Xr iscntrl 3 ,
.Xr isdigit 3 ,
.Xr isgraph 3 ,
.Xr islower 3 ,
.Xr isprint 3 ,
.Xr ispunct 3 ,
.Xr isspace 3 ,
.Xr isupper 3 ,
.Xr isxdigit 3 ,
.Xr tolower 3 ,
.Xr toupper 3 ,
.Xr ascii 7
.Sh STANDARDS
These functions, with the exception of
.Fn isblank ,
conform to
.St -ansiC .
All described functions, including
.Fn isblank ,
also conform to
.St -p1003.1-2001 .
.Sh CAVEATS
The first argument of these functions is of type
.Vt int ,
but only a very restricted subset of values are actually valid.
The argument must either be the value of the macro
.Dv EOF
(which has a negative value),
or must be a non-negative value within the range representable as
.Vt unsigned char .
Passing invalid values leads to undefined behavior.
.Pp
Values of type
.Vt int
that were returned by
.Xr getc 3 ,
.Xr fgetc 3 ,
and similar functions or macros
are already in the correct range, and may be safely passed to these
.Nm ctype
functions without any casts.
.Pp
Values of type
.Vt char
or
.Vt signed char
must first be cast to
.Vt unsigned char ,
to ensure that the values are within the correct range.
The result should then be cast to
.Vt int
to avoid warnings from some compilers.
Casting a negative-valued
.Vt char
or
.Vt signed char
directly to
.Vt int
will produce a negative-valued
.Vt int ,
which will be outside the range of allowed values
(unless it happens to be equal to
.Dv EOF ,
but even that would not give the desired result).