Re: sed: must do append before delete?

[Andreas Schwab]

address@hidden (Dan Jacobson) writes:

|> Interesting, very interesting, where is the logic to defend:
|> 
|> $ yes|sed 2q|sed '$d;$a\
|> > hello'
|> y
|> $ yes|sed 2q|sed '$a\
|> > hello
|> > $d'
|> y
|> hello
|> $ sed --version
|> GNU sed version 3.02
|> 
|> seems backwards to me.  I delete the line and then write something
|> there, instead that something gets deleted.  Instead I write something
|> there and then delete that line and instead it stays.  Using the i
|> command instead of the a command one gets the same results.  Using
|> s/.*// instead of d allows the hello thru though...

I'd guess the logic is that $d causes the address $ to not exist any more,
so that $a is not executed.  Like this:

$ yes|sed 2q|sed '1d;1a\
> hello'
y

Andreas.

-- 
Andreas Schwab                                  "And now for something
address@hidden                          completely different."
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