sed replace with variable with multiple lines [duplicate]

Answer 1

Given that you're using Bash, you can use it to substitute \n for the newlines:

sed -e "s/TOREPLACE/${TEST//$'\n'/\\n}/" file.txt

To be properly robust, you'll want to escape /, & and \, too:

TEST="${TEST//\\/\\\\}"
TEST="${TEST//\//\\/}"
TEST="${TEST//&/\\&}"
TEST="${TEST//$'\n'/\\n}"
sed -e "s/TOREPLACE/$TEST/" file.txt

If your match is for a whole line and you're using GNU sed, then it might be easier to use its r command instead:

sed -e $'/TOREPLACE/{;z;r/dev/stdin\n}' file.txt <<<"$TEST"

Answer 2

You can just write the script as follows:

sed -e 's/TOREPLACE/a\
b\
c\
/g' file.txt

A little cryptic, but it works. Note also that the file won't be modified in place unless you use the -i option.

Answer 3

An interesting question..

This may get you closer to a solution for your use case.

read -r -d '' TEST <<EOI
a\\
b\\
c
EOI

echo TOREPLACE | sed -e "s/TOREPLACE/${TEST}/"
a
b
c

I hope this helps.

Answer 4

tricky... but my solution would be :-

read -r -d '' TEST <<EOI
a
b
c
EOI

sed -e "s/TOREPLACE/`echo "$TEST"|awk '{printf("%s\\\\n", $0);}'|sed -e 's/\\\n$//'`/g" file.txt

Important: Make sure you use the correct backticks, single quotes, double quotes and spaces else it will not work.