query on using awk/egrep to extract specific String

Question

VOLUMES eu-west-1b  90      30              snap-54d6abac   in-use     vol-a60879a4    gp2
VOLUMES eu-west-1b  150     50              snap-8218247a   in-use     vol-6ee29c6c    gp2
VOLUMES eu-west-1b  50                      snap-8518247d   in-use     vol-76e29c74    standard
VOLUMES eu-west-1b  300     100             snap-bcef1047   in-use     vol-d22167d0    gp2
VOLUMES eu-west-1b  30                      snap-1e3ec2e6   in-use     vol-98efba9a    standard
VOLUMES eu-west-1b  24      8               snap-1b3ec2e3   in-use     vol-99efba9b    gp2
VOLUMES eu-west-1b  False   24      8       snap-1b3ec2e3   available  vol-4691b244    gp2

I have the below script that returns the above result /usr/bin/aws ec2 describe-volumes --output text | /bin/grep "VOLUME"

I am trying to extract only the column (8) - i.e. words that start with vol-

/usr/bin/aws ec2 describe-volumes --output text | /bin/grep "VOLUME" | /usr/bin/awk '{ print $6 }'

I did the following change but this returns

in-use
in-use
vol-76e29c74
in-use
vol-98efba9a
in-use
in-use
vol-6591b267
vol-01c6e403
in-use
in-use
vol-0e416c0c
vol-d1f28684
vol-f7d5a2a2
vol-84f4eca8
available

Because column 5 is blank for some of the lines - so the result looks incorrect.

Can some one point me on how to extract only strings starting with 'vol-'

I don't want to use perl - since I am not sure if the library is installed, I need to use egrep or awk.

regards D

Answer 1

how about looking in the other direction?

..... awk '{print $(NF-1)}'

Answer 2

Grep:

grep -oE '\bvol-\S+'

for the above example prints

vol-a60879a4
vol-6ee29c6c
vol-76e29c74
vol-d22167d0
vol-98efba9a
vol-99efba9b
vol-4691b244

both greps together

aws ... | grep -oP '^VOLUMES.*\K\bvol-\S+'

prints

vol-a60879a4
....
etc..