Question

If I have a string like: a.com b.com c.com

How can I add to the front of it to make it like *.a.com *.b.com *.c.com using Bash?

Answer 1

Assuming that we have a file named testfile with the following content:

a.com b.com c.com

You can use:

sed -i 's/^/\*./g;s/ / *./g' testfile

If you like to use it in shell directly:

echo "a.com b.com c.com" | sed 's/^/\*./g;s/ / *./g'