[U-Boot] U-boot env variables parsing

Detlev Zundel dzu at denx.de
Thu Apr 8 18:06:40 CEST 2010


Hi Jocke,

[...]

> Since an escape char appear to exist, one should be able to use it much like you
> did above so I don't think that any use case disappears. Instead the common usage
> becomes simpler and the so far artificial use case needs an extra escape char.

Hm.  I have to admit that I did not actually try your code, but there is
a loop in there until no further substitution takes place.  It seems to
me that this loop over process_macros thus does substitution _and_ uses
up the escape characters.  

So I fear that if in one iteration _some_ substitution takes place and
the escape character is stripped in the same iteration _another_ round
of substitution will be done and the escape character is gone.  So in
effect you will have to study the whole string in advance (plus all the
substitutions it will see) to tell how many rounds the loop will take
and how many escape characters will be needed.

Such a behaviour would be very odd in my eyes.  On the other hand, this
is only theory....

Cheers
  Detlev

-- 
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