Insert newline (\n) using sed

Question

I am trying to scrub some lists into a properly formatted CSV file for database import.

My starting file, looks something like this with what is supposed to be each &

Answer 1

Add a line after a match.

The sed command can add a new line after a pattern match is found. The "a" command to sed tells it to add a new line after a match is found.

sed '/unix/ a "Add a new line"' file.txt

unix is great os. unix is opensource. unix is free os.

    "Add a new line"
    
    learn operating system.
    
    unixlinux which one you choose.
    
    "Add a new line"

Add a line before a match

The sed command can add a new line before a pattern match is found. The "i" command to sed tells it to add a new line before a match is found.

sed '/unix/ i "Add a new line"' file.txt

"Add a new line"

unix is great os. unix is opensource. unix is free os.

learn operating system.

"Add a new line"

unixlinux which one you choose.

Answer 2

The sed on BSD does not support the \n representation of a new line (turning it into a literal n):

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1\n next line/'
123n next line

GNU sed does support the \n representation:

$ echo "123." | gsed -E 's/([[:digit:]]*)\./\1\nnext line/'
123
next line

Alternatives are:

Use a single character delimiter that you then use tr translate into a new line:

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1|next line/' | tr '|' '\n'
123
next line

Or use an escaped literal new line in your sed script:

$ echo "123." | sed -E 's/([[:digit:]]*)\./\1\
next line/'
123
next line

Or use awk:

$ echo "123." | awk '/^[[:digit:]]+\./{sub(/\./,"\nnext line")} 1'
123
next line

Or use GNU sed which supports \n

Answer 3

The following works on Oracle Linux, x8664:

$ echo 'foobar' | sed 's/foo/foo\n/'
foo
bar

If you need it to match more than once per line, you'll need to place a g at the end, as in:

$ echo 'foobarfoobaz' | sed 's/foo/foo\n/g'
foo
barfoo
baz

Answer 4

The portable way to get a newline in sed is a backslash followed by a literal newline:

$ echo 'foo' | sed 's/foo/foo\
bar/'
foo
bar

I guarantee there's a far simpler solution to your whole problem by using awk rather than sed though.