How can I create a file with multiple lines from the command-line?

Question

How can I enter the following contents in a file:

Hi
abcd

I tried using echo "Hi\nabcd" >> ab.txt, but in the file it's written as is (the \n is included, instead of a newline)

Answer 1

You need to tell echo to honor escape sequences.

echo -e "Hi\nabcd" >> ab.txt

Answer 2

The behavior of echo varies from shell to shell¹; printf's behavior is more standard.

printf "Hi\nabcd" >> ab.txt

¹ "It is not possible to use echo portably across all POSIX systems unless both -n (as the first argument) and escape sequences are omitted."

Answer 3

You can also play games with quoting:

 % echo 'Hi
> abcd' >> ab.txt

You type that in bash by hitting "Enter" after "Hi". Bash uses '>' as its continuation-of-command prompt for me. I could not escape an individual return with a backslash for some reason.

Answer 4

You can also just do cat > file, then type away and hit Ctrl-D when you're done.