Date: Tue, 21 Apr 2009 18:13:37 +0200
From: Spiro Trikaliotis <an-cygwin@spiro.trikaliotis.net>
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User-Agent: Mutt/1.5.17+20080114 (2008-01-14)
Subject: Re: [1.7] Updated: cygwin-1.7.0-45
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Hello,

* On Tue, Apr 21, 2009 at 05:23:34PM +0200 Corinna Vinschen wrote:
> On Apr 14 19:08, Thomas Wolff wrote:
> > On April 14, Corinna Vinschen wrote:
[...] 
> This is a real problem.  In the OEM codepages the 0xff character is a
> non-breaking space.  Unfortunately there's no way to distinguish between
> the (signed) char value 0xff and EOF when it's put as argument into the
> ctype functions.  sed has a loop which loops over all blank characters
> in the input, basically like this:
> 
>   do {
>     ch = inchar ();
>   } while (isblank (ch);
> 
> As soon as inchar() is at the end of the input, it returns EOF == -1.  And
> then the loop never stops, because the character value -1 is a blank
> character.
> 
> However, this appears to be a generic problem with the character with
> value 0xff.  If char is signed, its value is -1 and it can't be
> distinguished from EOF.
> 
> The only solution for this problem is, AFAICS, to treat the character
> 0xff as a non-character, for which all ctype functions return 0.

No. The real solution is to define ch as int in the first place. This
way, ch = 0xff is the printable character, while ch = -1 is EOF. Look at
the prototypes of the functions in ctype.h, they all take int as an
argument. And getchar(), getc() and getch() all return an int, not a
char. There's a reason for this.

Regards,
Spiro.

-- 
Spiro R. Trikaliotis                              http://opencbm.sf.net/
http://www.trikaliotis.net/                     http://www.viceteam.org/

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