Only return the matched string in sed [duplicate]

Question

Possible Duplicate:
Extracting a regex matched with 'sed' without printing the surrounding characters

How do I make this only print test:

echo "atestb" | sed -n 's/\(test\)/\1/p'

Must use sed? grep's -o switch looks like a shorter and cleaner way: echo "atestb" | grep -o 'test'.
I can't use sed because the real thing is like echo 'afoo="test"b' | sed -n 's/.*foo="\([^"]*\)".*/\1/p', where I only want to match test.

Thor · Accepted Answer · 2012-07-15 21:41:13Z

up vote 5 down vote accepted

You need to match the whole line:

echo "atestb" | sed -n 's/.*\(test\).*/\1/p'

or

echo "atestb" | sed 's/.*\(test\).*/\1/'

answered Jul 15 '12 at 21:41

Thor
4,721827

marked as duplicate by Gilles, Mat, Renan, jasonwryan, Stéphane Gimenez Aug 20 '12 at 17:06