How to add a line break in a pipe-received output, using sed, only for cases that fit the established pattern?
I used sed "s/.*oo.*/&\n/" to no avail. The default is OK, but the addition of the new line does not. I need to know what to put there where it is \n .
Examples of results I hope:
No Match:
echo 'bravo bar' | sed "s/.*oo.*/&\n/"
Expected output:
bravo bar
Match:
echo 'foo bar' | sed "s/.*oo.*/&\n/"
Expected output:
foo
bar
Use sed 's/.*oo.*/&\'$'\n/g' but to get foo you need to improve the default:
echo 'foo bar' | sed 's/.*oo/&\'$'\n/g'
& represents ALL the string that matches the pattern, so you're only adding a line break to the end of the line.
This here generates the expected output:
echo 'foo bar' | sed 's/\(.*oo\) \(.*\)/\n/g'
Using Gnu-sed (present in linux and easily installable everywhere, and times with the name gsed) the example proposed by the OP works with slight modification:
sed echo 'foo bar' | sed 's/.*oo/&\n/'
output
foo
bar
@HenriqueBarcelos presented some richer examples with re-use of substrings which obviously works great on GnuSed.
To highlight the potentiality of this issue, along with a slightly more complex example that changes site line breaks:
Given a text with broken words:
$ cat texto
Exemplo
aqui vai um tex-
to que tem trans-
lineações a dar
com um pau!
change the word continuations to the previous line!
$ sed -zre 's/-\n([^ ]+) /\n/g' texto
Exemplo
aqui vai um texto
que tem translineações
a dar
com um pau!