regex submatch replace

I'm trying to replace all occurrences of a word but only when is placed inside a pair of delimiters. Example:

Original: asdf oldfoo asdf ("asdf oldfoo asdf oldfoo asdf") asdf oldfoo asdf
Desired:  asdf o开发者_StackOverflow中文版ldfoo asdf ("asdf newfoo asdf newfoo asdf") asdf oldfoo asdf

Is there any way to do it with sed or awk?

Thanks!

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If the delimiters are '("'and '")' and only one occurrence of the delimiters occurs per line:

sed -e ':begin;s/\(.*(".*\)oldfoo\(.*").*\)/\1newfoo\2/;t begin'

It does not work if you have multiple occurrences per line as the 'oldfoo' in the middle bellow happen to be inside the outer delimiters:

asdf oldfoo asdf ("asdf oldfoo asdf oldfoo asdf") asdf oldfoo asdf ("asdf oldfoo asdf oldfoo asdf") asdf oldfoo asdf

If your delimiters are '('and ')' , this works even if you have multiple delimiters per line:

sed -e ':begin;s/\(.*([^)]*\)oldfoo\([^(]*).*\)/\1newfoo\2/;t begin'

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yes, as @nobody mentioned, it's something like

oldfoo(?=[^"]*"([^"]*"[^"]*")*[^"]*$)

i guess you'll probably have to play with escaping of " a bit to make it work correctly with awk/sed

if you have perl it would be

perl -pe 's/oldfoo(?=[^"]*"([^"]*"[^"]*")*[^"]*$)/newfoo/g' whatever.txt

EDIT: ok sorry, i didn't know that sed/awk don't support lookahead/lookbehind at all. I'm afraid that there is no way to do this task without at least lookahead.