Grep command

Applications UNIX Desktop Questions & Answers
1

Hi,

Could someone tell me in this line:

/dev/hda2 12001268 1538572 9843232 14% /

How could i grep so it only shows when the number is from 90% to 100%?

i've tried df -k | grep '/dev/hda2' | cut -c 53-55 | grep '^9' | grep '^100'

but it dosent work.

Thanks in advance

2

Try this:

df -k | grep '/dev/hda2'| awk '{sub("%","",$5) ; if($5>89) print}'
3

If you are looking for alerting when the hard disk reaches 90%, then perl is more reliable than checking in this way of GREP, and commands..

This will help you a lot: Perl script to monitor disk space and send an email

4 
df -HP | { while read disk b c d used e
do    
        used=${used%?}
        case  "$used" in
        [9][0-9]|100)
            echo "overload over 90%: $disk, used: $used%"
        esac
done 
}
5

I don't get how perl could be "more reliable". Both Perl and the shell/awk results are 100% correct for such a simple task.

6

that's right. I think he is talking about all those extra greps, which are totally unnecessary.

7

Go it:

df -k | awk '$1 == "/dev/hda2" {sub("%","",$5) ; if($5>89) print}'

or the simpler if all filesystems are to be tested:

df -k | awk '{sub("%","",$5) ; if($5>89) print}'
8

thanks guys, it did the job :slight_smile: