Adding (not replacing) a pattern match with a similar pattern?
I'm writing a bash script to search html files, and when I find any occurrence of an img src tag like this:
<img src="123-picture-normal.jpg" alt="some random user entered text" border="0">
I want to add a second line below it that looks like:
<img src="123-picture-thumbnail.jpg" alt="some random user entered text" border="0">
All I need to do is duplicate the line but replace "normal" with "thumbnail"
Each file can have multiple img src tags with different numbered jpgs.
I have a feeling this is a job for sed, but I'm struggling with it. Any ideas?