Replace newlines in multiline input with “\n”

Question

I've been trying to do some work with generating SQL commands with an interactive bash script and have a multiline string that I need to escape for use with MySQL.

Notes has already been defined as a multi-line string.

notes=$(echo "$notes" | php -r 'echo mysql_escape_string(fgets(STDIN));');

However, only one line is being returned. How can I get my multiline string properly escaped and returned?

Answer 1

Use pattern substitution:

notes=${notes//$'\n'/\\n}