Hi all, I'm trying to use sed to replace multiple occurrences of a
word with a single one.

I have a line as follows:

..*Comment:Comment:Comment:.* where the .* is text that is irrelevant
to this post.

I want to replace the multiple occurrences of "Comment:" with a single
"Comment:".

I can't do it within Vim 7.0. Apparently the quantifiers apply to
repetitions of characters and not words.
So :%s/Comment:\{2,}/Comment:/ doesn't work in Vim.

Er, yes, I know this is a shell forum but I'm just posting what I
tried.

I tried it in sed but I'm a sed newbie and the command 's/Comment://2'
will delete only the second occurrence. I couldn't find out how to
delete all the occurrences from the second one onwards.

Can someone out with the right command using sed, vim or awk (in
that order?)

Thanks,
Sashi

Sashi wrote:
> Hi all, I'm trying to use sed to replace multiple occurrences of a
> word with a single one.
>
> I have a line as follows:
>
> .*Comment:Comment:Comment:.* where the .* is text that is irrelevant
> to this post.
>
> I want to replace the multiple occurrences of "Comment:" with a single
> "Comment:".
<snip>

$ echo ".*Comment:Comment:Comment:.*" |
sed 's/Comment:\(Comment:\)*/Comment:/'
..*Comment:.*

Regards,

Ed.

On Sep 4, 10:20 am, Ed Morton <mor...@lsupcaemnt.com> wrote:
> <snip>
>
> $ echo ".*Comment:Comment:Comment:.*" |
> sed 's/Comment:\(Comment:\)*/Comment:/'
> .*Comment:.*
>
> Regards,
>
> Ed.

Thank you, Ed.
I'm using sed on Solaris 10 and it didn't work with default /usr/bin/
sed but worked with /usr/xpg4/bin/sed.

Regards,
Sashi

On Sep 4, 5:06 pm, Sashi <small...@gmail.com> wrote:
> Hi all, I'm trying to use sed to replace multiple occurrences of a
> word with a single one.
>
> I have a line as follows:
>
> .*Comment:Comment:Comment:.* where the .* is text that is irrelevant
> to this post.
>
> I want to replace the multiple occurrences of "Comment:" with a single
> "Comment:".
>
> I can't do it within Vim 7.0. Apparently the quantifiers apply to
> repetitions of characters and not words.
> So :%s/Comment:\{2,}/Comment:/ doesn't work in Vim.
>
> Er, yes, I know this is a shell forum but I'm just posting what I
> tried.
>
> I tried it in sed but I'm a sed newbie and the command 's/Comment://2'
> will delete only the second occurrence. I couldn't find out how to
> delete all the occurrences from the second one onwards.
>
> Can someone out with the right command using sed, vim or awk (in
> that order?)
>
> Thanks,
> Sashi

This works just fine ... :-)
>echo 'Comment:Comment:Comment:' | sed 's/\(Comment:\)\{1,\}/\1/'
Comment:

The reason this does not work with /bin/sed is that that version of
'sed' doesn't support
a multi-atom RE followed by \{m,n\} . The GNU version of 'sed' can
handle that though.

In order to do it with the /bin/sed version you would have to iterate,
for example:

echo '.....' |
sed -e '
:a
s/\(Comment:\)\1/\1/
ta
'



On Sep 4, 7:06 pm, Sashi <small...@gmail.com> wrote:
> I have a line as follows:
>
> .*Comment:Comment:Comment:.* where the .* is text that is irrelevant
> to this post.
>
> I want to replace the multiple occurrences of "Comment:" with a single
> "Comment:".
>
> I can't do it within Vim 7.0. Apparently the quantifiers apply to
> repetitions of characters and not words.
> So :%s/Comment:\{2,}/Comment:/ doesn't work in Vim.
>