[Techtalk] finding added lines in a file

[Chris Wilson]

Hi Miriam,

On Fri, 16 Aug 2013, Miriam English wrote:

> Thanks Bonnie. That's very cool. I wouldn't have thought of using grep like 
> that.
>
> One problem I've noticed with my solution and yours is that if a new line is 
> added to B that happens to be the same as an existing line elsewhere in A it 
> is lost. For example, say A and B are revisions of a story and both versions 
> have a line '"Yes," she said.' early in both files, if there is another new 
> line added to B later with the same wording, but unrelated to the original, 
> so it is truly a new line, it is nevertheless lost. It is, of course, because 
> of the sort, which removes context, which is why I've been trying to fathom 
> the manuals of cmp, diff, and comp. I normally like reading manuals...

In that case, try "diff -u A.txt B.txt".

You can use grep to find only the added lines, and sed to remove the 
'+' signs if you want. For example:

   diff -u A.txt B.txt | grep '^+' | sed -e 's/^+//'

Cheers, Chris.
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