Extraction of text using sed or awk command

Shell Programming and Scripting
1

Hi All,
I need to extract 543 from the command below :

[root@puiqtk06 ]# pvscan
  PV /dev/sdb1   VG vg0   lvm2 [543.88 GB / 896.00 MB free]
  Total: 1 [543.88 GB] / in use: 1 [543.88 GB] / in no VG: 0 [0   ]

I have the following command which does the job, but I think this could be achieved in a more simple way using sed or awk. Any help is appreciated.

pvscan | grep Total | tr -s " " | cut -d " " -f4 | tr -s "[" " " | cut -d "." -f1
2

hope this helps:

pvscan | grep Total |sed 's/\(.*\)\(\[[0-9][0-9][0-9]\)\(.*\)/\2/g'
3

or:

pvscan | awk -F '[[.]' '/Total/{print $2}'
4

Using awk command I get the following error :

[root@puiqtk06 ]# pvscan | awk -F '[[.]' '/Total/{print $2}'
awk: fatal: Unmatched [ or [^: /[[.]/

Using sed , we are pretty close except that "[" also comes in the value.

[root@puiqtk06 ]# pvscan | grep Total |sed 's/\(.*\)\(\[[0-9][0-9][0-9]\)\(.*\)/\2/g'
[543
[root@puiqtk06 ]#
5

Perhaps your awk likes the [ needs to be escaped:

pvscan | awk -F '[\[.]' '/Total/{print $2}'

or:

pvscan | sed -n '/Total/{s/[^[]*\[//;s/\..*//p}'
6

ohh it should have been

 pvscan| grep Total|sed 's/\(.*\)\(\[\)\([0-9][0-9][0-9]\)\(.*\)/\3/g'
7 
line=$(pvscan|grep Total)
line=${line#*\[}
echo ${line%%.*}
8

Works like a charm using both!

Thanks Scrutiniszer and shivdatta!! Appreciate all the help!