Fill placeholders in file in single pass

Question

I have a skeleton text file with placeholder strings:

blah blah blah
blah $PLACEHOLDER_1$
blah
$PLACEHOLDER_2$

and so on. Specific \"form\" of

Answer 1

You can still use sed to do the replace in a single pass. You just need to specify all the replacements in one command.

eg.

sed -i 's/PLACEHOLDER_1/string 1/g;s/PLACEHOLDER_2/string 2/g'