I don't know why you get an error as it works on my FC5 box.
cat file.txt
I have a red PET
and some more
stuff here.
cat myscript
s/red PET/beautiful red PET/
Code:
sed -f myscript file.txt
I have a beautiful red PET
and some more
stuff here.
sed --version
GNU sed version 4.1.5
Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE,
to the extent permitted by law.