sed -i

[Yar Tikhiy]

On Thu, Mar 29, 2007 at 11:19:44AM +0300, Diomidis Spinellis wrote:
> Yar Tikhiy wrote:
> >
> >Recently noticed that our sed(1) differs from its GNU analog in
> >that in -i mode it considers all files as a single sequence of lines
> >while the latter treats each file independently.  The in-line mode
> >isn't in POSIX, so it isn't really clear which way is correct.
> >
> >Here is a couple of practical consequences:
> >
> >- our sed won't act on a numeric range of lines in each file,
> >  as in: sed -i '' 2,5d *, which may be counter-intuitive.
> >- our sed's line ranges can span file boundaries in -i mode.
> >
> >If the second feature isn't important, I think we should use
> >a separate line space for each file edited in-line, which is
> >usually desired.
> >
> >Comments?
> >
> >P.S. Attached are a test script and outputs from it for our
> >sed and GNU sed as found in a Linux I have access to.
> >
> 
> I believe the GNU interpretation of lines in -i makes sense.

Hurray!  I've got a blessing from the author of BSD sed himself! :-)
Thank you!

May I take a bit more of your time?

I've started playing with the code and noticed another gray area.
Namely a `c' command won't print the text if having 2 addresses
with the 2nd address beyond the actual end of file.  For example:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BEGIN
$ jot 9 |
> sed '6,15c\
> text
> ' test
1
2
3
4
5
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% END

Ditto with RE's, if the 2nd RE doesn't match any line:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BEGIN
$ jot 9 | sed '/6/,/15/c\
> text
> ' test
1
2
3
4
5
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% END

If we've started to delete the pattern space, we should print the
text in place of it because `c' is for `change'.  BSD and GNU seds
have this bug, but Solaris sed doesn't have it.  Do you think we
should fix it, too?

Thanks!

-- 
Yar