LinuxQuestions.org - [SOLVED] why is this for loop not entered?

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why is this for loop not entered?

hello linux q

I just wrote this script to shutdown my list of xen machines, back them up via rsync, then restart them. And can't for the life of me figure out why it never enters into the first (and likely other) for loop(s)

Code:



#!/bin/bash

VMLIST1='vm01 vm02 vm03 vm04 vm05 vm06 vm07 vm08 vm09'

VMLIST2='vm10 vm11 vm12 vm13 vm14 vm15'



for i in `/usr/bin/virsh list | /bin/grep -v -e Id -e --- -e 0 | /bin/awk '{print $1}'`; do /usr/bin/virsh shutdown $i; echo "shutting down session $i"; sleep 5; echo; echo; done



sleep 300



ssh sum2 "for i in `virsh list | /bin/grep -v -e Id -e --- -e 0 | /bin/awk '{print $1}'`; do virsh shutdown $i; echo "shutting down session $i"; sleep 5; echo; echo; done"



sleep 300



/usr/bin/rsync -avzp /mnt/store/xen/ /mnt/nas/xen/



sleep 300



for a in $VMLIST1; do /usr/sbin/xm create /mnt/store/xen/$a; echo "starting $a"; sleep 5; done







ssh sum2 "for a in $VMLIST2; do /usr/sbin/xm create /mnt/store/xen/$a; echo "starting $a; sleep 5; done"

I'd appreciate any suggestions you may have...

The first question will have to be what the output of

Code:

/usr/bin/virsh list | /bin/grep -v -e Id -e --- -e 0 | /bin/awk '{print $1}'

is :}

Cheers,
Tink

ah! the output was nothing, tho I honestly thought I saw some output from the same line before.

this line did the trick!!

Code:

/usr/bin/virsh list | /bin/grep -v -e Id -e --- -e 'Domain-0' | /bin/awk '{print $1}'

so now that I am grepping for Domain-0 and not just 0 all is well..

thanks and best wishes!!

Heh ... anytime ;}

Cheers,
Tink

Personally I would ask why the use of grep at all seeing awk would do all the work you have written.
Also a preference is to use $() at least when showing code here as very difficult for some of us oldies to pick up where the backticks start and stop :(