sed - how to do regex groups using sed

Question

Is there anyway you can do regex match group using sed like java regex pattern/match/group?

if i have string like

test-artifact-201251-balbal-0.1-SNAPSHOT.jar

how do I use sed just to get the result like:

test-artifact-0.1-SNASHOT.jar

I am wondering does sed allow you to do something like java regex, you define the pattern like:

([a-z]*-[a-z]*-)([0-9]*-)([a-z]*-)([.]*SNAPSHOT.jar)

and then you can get the results as an array like:

test-artifact-
201251-
balbal-
0.1-SNAPSHOT.jar

http://stackoverflow.com/questions/2777579/how-to-output-only-captured-groups-with-sed — Ciro Santilli OurBigBook.com, Oct 07 '15 at 13:42

Birei · Accepted Answer · 2012-07-25T13:51:50.073

79

You have to escape parentheses to group expressions:

\([a-z]*-[a-z]*-\)\([0-9]*-\)\([a-z]*-\)\([.]*SNAPSHOT.jar\)

And use them with \1, \2, etc.

EDIT: Also note just before SNAPSHOT that [.] will not match. Inside brackets . is literal. It should be [0-9.-]*

edited Jul 25 '12 at 13:51

answered Jul 25 '12 at 13:46

Birei

25

With GNU `sed` you can avoid all the escaped parenthesis by using extended regular expressions. Use the `-r` switch to do this. – Thor Jul 25 '12 at 13:59
4

`-E` also works in GNU to not need to escape parens. – abalter Oct 14 '16 at 17:11

score 24 · Answer 2 · answered Jul 25 '12 at 13:59

24

This is what Birei and Thor mean:

sed -r "s/([a-z]*-[a-z]*-)([0-9]*-)([a-z]*-)(.*)/\1\n\2\n\3\n\4/"

Output:

test-artifact-
201251-
balbal-
0.1-SNAPSHOT.jar

answered Jul 25 '12 at 13:59

Steve

score 7 · Answer 3 · answered Jul 25 '12 at 14:05

infact for those regular string, awk could save you from grouping. :)

you just give the part index number you want:

awk 'BEGIN{FS=OFS="-"}{print $1,$2,$5,$6}'

output:

kent$  echo "test-artifact-201251-balbal-0.1-SNAPSHOT.jar"|awk 'BEGIN{FS="-";OFS="-"}{print $1,$2,$5,$6}'
test-artifact-0.1-SNAPSHOT.jar

score 3 · Answer 4 · answered Sep 27 '16 at 19:10

If you are searching for an easier way I guess this might be of your help! :)

echo "est-artifact-201251-balbal-0.1-SNAPSHOT.jar" | cut -d- -f1,2,5,6

"-" used as delimeter and fields 1,2,5,6 are printed.

Note: This would require you to know the exact position of the field.

4 Answers4