Using variables in sed -f (where sed script is in a file rather than inline)

Question

We have a process which can use a file containing sed commands to alter piped input.

I need to replace a placeholder in the input with a variable value,

Answer 1

To add a newline in the replacement expression using a sed file, what finally worked for me is escaping a literal newline. Example: to append a newline after the string NewLineHere, then this worked for me:

#! /usr/bin/sed -f
s/NewLineHere/NewLineHere\
/g

Not sure it matters but I am on Solaris unix, so not GNU sed for sure.