Re: lines matching N and N+1

Yes, I did mean "word" as in GNU sed \<word\> sense.

With the "test file" and "desired output" I mentioned, 
here's what I came up with, similar to something I saw
from Y-J Chang. It assumes using -r command line option.

$! N 
s:(.*)\<foo\>(.*)\n(.*)\<bar\>(.*):\1FOO\2\n\3BAR\4:
t    
P; D 

# Append next line if NOT last line of file
# Try changing foo in line #1, bar in line #2
# If change happened, print lines and read a new pair
# Else, print & delete line #1, run N to make next pair

This seems similar to some of the other solutions 
that were posted.

Thanks,
Daniel

--- In [email protected], Davide Brini  wrote:
>
> On Mon, 28 Jan 2013 20:18:23 -0000, "Daniel"  wrote:
> 
> > This came up in a recent cross-Atlantic conversation. :)
> > 
> > The problem: How to apply a change when a *combination* 
> > of lines occurs, eg when the word "foo" appears in line 
> > N and the word "bar" appears in line N+1. How then to 
> > apply the change in line N (or line N+1)? For example, 
> > change word "foo" to "FOO" and word "bar" to "BAR".
> > 
> > Here's a test file I dreamed up:
> > 
> > food foot foo
> > bare bark bar
> > bar bark bare
> > bark bar bare
> > foot foo food
> > bark bar bare
> > foot foo food
> > foo foot food
> > bar bark bare
> > foot foo food 
> > 
> > Here's the desired output:
> > 
> > food foot FOO
> > bare bark BAR
> > bar bark bare
> > bark bar bare
> > foot FOO food
> > bark BAR bare
> > foot foo food
> > FOO foot food
> > BAR bark bare
> > foot foo food 
> > 
> > I tried doing this in bash and couldn't make it
> > work. I do have a possible sed solution.
> > 
> > Thought I'd post this, see if anyone would like
> > to take a look, either sed or bash (or whatever!).
> 
> I assume that you use "word" as meant by GNU sed's \< and \> operators (or
> \b). Leaving out some unspecified corner cases:
> 
> $!N
> s/\ \(.*\n.*\)\ /FOO\1BAR/
> P
> D
> 
> If "foo" and "bar" are regular expressions and not fixed strings, turning
> them to uppercase is more complicated, yet still possible using GNU sed
> (which I'm assuming anyway);
> 
> $!N
> s/\(\ \)\(.*\n.*\)\(\ \)/\U\1\E\2\U\3\E/
> P
> D
> 
> 
> -- 
> D.
>