No sure if I can do this easily but:

I have a file like


Now I want to grep by /dev/dev/my_dev2 and get the volume name and domain name. I'm getting the volname by:

volname=`grep $dsk ldm_ls-o_disk.out|uniq|cut -d\| -f2|cut -d= -f2`

this will give me disk02 but now I'm stuck on how to get the domain name since I can have several VDISK and the number of lines between the VDISK and DOMAIN is variable. Basically I want to grep the volname and "search" back to find the DOMAIN tag and get the name from it.

  • Could you add an example or two of what the expected output would look like? For the DOMAIN lines you could do something like d=$(grep "DOMAIN|name=" | cut -d= -f2) from the way that I understand the question, but I don't think that is what you are asking. – jmunsch Dec 6 '14 at 21:09
  • I want to find the domain associated with a device. Mainly I have a list of devices, I find their volume name (vol=name) and then I want to get the domain they are assigned to. – BitsOfNix Dec 6 '14 at 21:22

Assuming the domain is the most recent before the matching VDISK line, I'd use awk:

awk -F '[=|]' -v dev="/dev/dev/my_dev2" '
    $1 == "vol" && $5 == dev {vol = $2}
    $1 == "DOMAIN" {domain = $3}
    $1 == "VDISK" && $3 == vol {print vol, domain; exit}
' file

This outputs

disk02 domain01

To capture those in shell variables use read with a process substitution:

get_domain () {
    awk -F '[=|]' -v dev="$1" '
        $1 == "vol" && $5 == dev {vol = $2}
        $1 == "DOMAIN" {domain = $3}
        $1 == "VDISK" && $3 == vol {print vol, domain; exit}
    ' file

read volume domain < <(get_domain "/dev/dev/my_dev2")
  • If you need to query several devices from this file, I'd use something like awk or perl to parse the whole file, and then output the domains for each respective device. – glenn jackman Dec 6 '14 at 21:40

For the moment I'm using this solution, but I would like something cleaner.

volname=`grep $dsk ldm_ls-o_disk.out|uniq|cut -d\| -f2|cut -d= -f2`
linenr=`grep -n $volname ldm_ls-o_disk.out |grep VDISK|cut -d\: -f1`
while [ $retval -eq 1 ]
        line=`sed -n "${linenr}p" ldm_ls-o_disk.out|grep DOMAIN`
        if [ $? -eq 0 ]; then
                domain=`echo $line |cut -d= -f2`
  • 1
    This isn't an answer: it should be an edit to your question. And please edit in information requested by jmunsch... – jasonwryan Dec 6 '14 at 21:22
  • this is an answer as it does exactly what I want, although it's slow and I would like something simpler. Doing like this to 200+ devices is just overkill. Although when I posted the question I had only volume name and was thinking on how to obtain the desired result. – BitsOfNix Dec 6 '14 at 21:24
  • 1
    Then you should be posting on Code Review, not here... – jasonwryan Dec 6 '14 at 21:29
  • since when? this is shell scripting question which is part of this site you can find more info -> unix.stackexchange.com/help/on-topic. – BitsOfNix Dec 6 '14 at 21:52

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