In GNU sed it will be something like this
's/foo/bar/3g' <<< "foofoofoofoofoo"
Output: "foofoobarbarbar"
The same command in BSD sed gives me a following error
sed: 1: "s/foo/bar/3g": more than one number or 'g' in substitute flags
How can I implement this on BSD sed?
I searched SO and found this but all the answers are for GNU. I read the man but am having a difficulty figuring this out.
One option is implementing a loop using a label and t command:
$ sed -e ':l' -e 's/foo/bar/3' -e 'tl' <<< 'foofoofoofoofoo'
foofoobarbarbar
Just be careful because if your replacement text is matched by your original RE (e.g. s/f.x/fox/) then you'll be stuck in an infinite loop and if it generates the original text after replacement then you'll get unexpected results, e.g.:
$ sed 's/foo/oo/3g' <<< 'foofoofffoo'
foofooffoo
$ sed -e ':l' -e 's/foo/oo/3' -e 'tl' <<< 'foofoofffoo'
foofoooo
Note above that the first version works because it's doing all replacements in 1 pass of the text so the previous replacement isn't considered part of the string for the current replacement pass.