[U-Boot] [PATCH] Ignore all Carriage Returns when importing an environment.

Wolfgang Denk wd at denx.de
Sat May 12 23:18:11 CEST 2012


Dear Alexander Holler,

In message <4FAE7232.1050407 at ahsoftware.de> you wrote:
>
> > I would like to put as little restrictions on the content of an
> > environment variable as possible.  I can see valid use for strings
> > that contain a CR character.
> 
> I don't see any reasonable usage for carriage returns in imported 
> environment variables, but I've seen many people from the windows camp 

A CR causes the output to re-start from start of line. I can
construct all kind of fancy disply by using "echo $var" - especially
so if "var" can contain control characters including CR.  It makes no
sense striiping these out.

> struggling in writing small text files to set some environment variables 
> (which mostly end up in the kernel cmdline). Especially because those 
> CR's often will lead to obscure errors because almost nothing (in u-boot 
> or linux) is able to handle them.

This is a problem that is as old as DOS, and solutions for this have
been known since.  I already mentioned dos2unix.

> Anyway I don't really care, I just found it very user friendly to strip 
> the carriage returns, especially for those embedded newbies which are in 
> need to use some unnamed windows IDE.
> 
> So I've decided (after having that patch lying around for about a year) 
> to finally post it.

Thanks - but it adds restrictions to doing perfectly valid things.  I
see the disadvantages significantly bigger than what we can win - keep
in mind, that dealing wqith DOS line endings is a topic that is
decades old.

Best regards,

Wolfgang Denk

-- 
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