I've got a file containing the text:
blah
grah

and I want to replace those two lines with the string:
broohaha

I've tried using:
perl -pi -e 's/blah\ngrah/broohaha/' file

I've also tried:
perl -pi -e 's/blah\ngrah/broohaha/s' file
perl -pi -e 's/blah\ngrah/broohaha/m' file
perl -pi -e 's/blah\ngrah/broohaha/ms' file

all with no success. What am I doing wrong? How do I replace a string that
spans multiple lines?

Thanks,
- Jared