Sed - How to print regular expression groups in multi-line mode?

Question

Input file (test):

123456<a id="id1" name="name1" href="link1">This is link1</a>789<a id="id2"
href="link2">This is link2</a>0123

Required Conclusion:

link1
link2

What I've done:

$ sed -e '/<a/{:begin;/<\/a>/!{N;b begin};s/<a\([^<]*\)<\/a>/QQ/;/<a/b begin}' test
123456QQ789QQ0123

Question: How do you print regex groups in sed ( multiline )?

+3

hahakubile May 12, '11 at 3:31

1 answer

anubhava · Accepted Answer · 2011-05-12T03:41:01+0000

If you use sed like this:

sed -e '/<a/{:begin;/<\/a>/!{N;b begin};s/<a\([^<]*\)<\/a>/\n/;/<a/b begin}'

then it will print in different lines:

123456
789
0123

But is that what you are trying to print? Or do you want to print text in hrefs?

sed -r '$!N; s~\n~~; s~(<a )~\n\1~ig; s~[^<]*<a[^>]*href\s*=\s*"([^"]*)"[^\n]*~\1\n~ig' test

Output

link1
link2

regex='href="([^"]*)"'
while read line; do
   [[ $line =~ $regex ]] || continue
   echo ${BASH_REMATCH[1]}
done < test

Output

link1
link2