Re: sh(1) read: add LINE_MAX safeguard and "-n" option

[tlaronde%kergis.com@localhost]

On Tue, Sep 24, 2024 at 06:54:35PM +0700, Robert Elz wrote:
>     Date:        Tue, 24 Sep 2024 12:56:49 +0200
>     From:        <tlaronde%kergis.com@localhost>
>     Message-ID:  <ZvKa8e8a7FHIFLz6%kergis.com@localhost>
> 
>   | The present patch does two things:
>   |
>   | 1) Set, by default, the maximum of bytes read, in every case, as being
>   | LINE_MAX (the maximum number of bytes in a line in a text file);
> 
> I am not really in favour of that part, while allowed by the standard,
> imposing unnecessary limits, just because they are permitted, is not
> really ideal.   Apart from that, the "line" read by read (without -r)
> can actually be several (or many) text file lines, if each is ended by
> a \ (line continuation).

In the present code, a delimiter can not be "any character": because
if the delimiter is the backslash, what shall be the behavior? 

Since backslash is defined to be the escape character, it can not be
used as a delimiter, unless specifying that all backslashes have to
be escaped to be accepted as end delimiter... But how to specify a
continuation line then?

Shouldn't we rule out backslash as a delimiter (for -d) (and POSIX has
to be amended). Or, if backslash is a delimiter, does this imply
"raw", i.e. no escaping club?

Furthermore the continuation test on:

			if (c != '\n')	/* \ \n is always just removed */
				goto wdch;

seems wrong. Shouldn't it be?:

	 if (c != end)
		goto wdch;

to accept whatever continuation line with whatever delimiter?

-- 
        Thierry Laronde <tlaronde +AT+ kergis +dot+ com>
                     http://www.kergis.com/
                    http://kertex.kergis.com/
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