[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: lynx-dev type of isdigit etc. (was: Relatively mild dev13 build prob
From: |
T.E.Dickey |
Subject: |
Re: lynx-dev type of isdigit etc. (was: Relatively mild dev13 build problems) |
Date: |
Sun, 31 Oct 1999 13:53:53 -0500 (EST) |
> FYI, a comment form GNU libc's ctype.h regarding that library's
> implementation:
>
> (The first sentence's "These" refers to macros that are used in the
> expansion of is*(), to*().)
>
> These point into arrays of 384, so they can be indexed by any `unsigned
> char' value [0,255]; by EOF (-1); or by any `signed char' value
> [-128,-1). ISO C requires that the ctype functions work for `unsigned
> char' values and for EOF; we also support negative `signed char' values
indeed (more common is to simply dump core when there's inadvertant sign-
extension)
> for broken old programs. The case conversion arrays are of `int's
> rather than `unsigned char's because tolower (EOF) must be EOF, which
> doesn't fit into an `unsigned char'. But today more important is that
> the arrays are also used for multi-byte character sets. */
for that, 384 entries won't work...
> So it accepts negative values only to cater for improper use.
>
> Klaus
--
Thomas E. Dickey
address@hidden
http://www.clark.net/pub/dickey
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: lynx-dev type of isdigit etc. (was: Relatively mild dev13 build problems),
T.E.Dickey <=