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

AFAIK, it's not possible. Your best bet will be :

INPUT FILE

aaa
bbb
ccc

SH SCRIPT

#!/bin/sh

STRING="${1//\//\\/}"   # using parameter expansion to prevent / collisions

shift

sed "
s/aaa/$STRING/
" "$@"

COMMAND LINE

./sed.sh "fo/obar" 

OUTPUT

fo/obar
bbb
ccc