Question

I want to remove the STRONG tags in a text-file.

I’m using sed 's/< strong>/>/g' for removing the STRONG tag and that works fine.

But when I want to remove the < /STRONG> tag with this sed 's/< /strong>//g'
it states the following error sed: -e expression #1, char 13: Unknown option tos’`

I believe it has to do with the < /-part but I don’t know what. Can somebody please explain me how to fix it?

The space between < and strong and others is on purpose for this question-only

Answer 1

Your problem is that you are using / as a pattern/replacement separator, if you want to match/replace one (/), you must escape it (like: \/) that way, but more on that see below.

sed is not an ideal tool for (X|HT)ML processing. If the tag does not span to multiple lines, it might work for you:

sed 's_</\s*\?strong>_>_g' INPUTFILE

This replaces both <strong>, < strong>, </strong>, < /strong> with a single > (as you had written in the question). sed can use several pattern/replacement separators, not just / (I’m using _ above.)