How to batch edit a list of files?

Question

I have a list of files where I need to remove some lines that have been added yesterday by a spambot. The section I want to remove looks like this:

^M <script>[...] bunch of malware code [...]</script> 

That section seems to have been appended to the files, so I can be relatively sure it's the last lines of each file that contain this part.

Now I know a bit of Linux, but not enough to do this via a command. How would I go about and do this?

Answer 1

Is the malware code consistent? does it start and end with the same text in all cases??

If you can write a regexp, you can do something like:

perl -npi.bak -e 's/startofcode.*?endofcode//' file1 file2 file3 orglob*