Help with AWK...

[psychosb]

Hello to all!

I would like some help...

I'm trying to use AWK to filter the results of the file /proc/mdstat in linux.

The content of the file is:

[root@hostname~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdq1[0] sdr1[1]
264960 blocks [2/2] [UU]
bitmap: 0/33 pages [0KB], 4KB chunk

md1 : active raid1 sdq2[0] sdr2[1]
142793664 blocks [2/2] [UU]
bitmap: 2/137 pages [8KB], 512KB chunk

I'm trying to create a script that runs the following command:

/sbin/mdadm -Q --detail /dev/mdX

Where the "X" is the number of devices listed on the mdstat file.

I wrote the following script, and it's working fine...
But I'm wondering if there's any way that i can do the same thing, without using the pipe to run the second awk (awk 'NR=='$a -> to get the line number).

for ((a=1; a <= 10 ; a++))
do
mdx=`awk '$1 ~ /^[md]/ {print substr($0,0,3)}' /proc/mdstat | awk 'NR=='$a`
if [[ -n "$mdx" ]] ; then
/sbin/mdadm -Q --detail /dev/$mdx
else
echo
fi
done

I've made a lot of tests trying to use the awk to invoke the system command but without any success.

Does anyone have a idea?

Thanks!

 

[feherke]

Hi

$1 ~ /^[md]/

Do you realize there you wrote if $1's first character is either "m" or "d" ?

As far as I understand it, this would be enough :

awk '$1~/^md/{print"/sbin/mdadm -Q --detail /dev/"$1}' /proc/mdstat | sh

Do you have to process /sbin/mdadm output too ?


Feherke.

 

[Annihilannic]

system() should also do the trick, although a fraction less efficient:

awk '[blue]$1[/blue]~[green]/^md/[/green]{[b]print[/b][red]"[/red][purple]/sbin/mdadm -Q --detail /dev/[/purple][red]"[/red][blue]$1[/blue]}' /proc/mdstat

Annihilannic
[small]tgmlify - code syntax highlighting for your tek-tips posts[/small]

 

[feherke]

Hi

Annihilannic, are you sure you intended to post that code ?


Feherke.

 

[Annihilannic]

Hehe... err... oops!

I was thinking more along these lines:

awk '[green]/^md/[/green]{[b]system[/b]([red]"[/red][purple]/sbin/mdadm -Q --detail /dev/[/purple][red]"[/red][blue]$1[/blue])}' /proc/mdstat

Thanks feherke... moral of the story, preview before you post! *sigh*


Annihilannic
[small]tgmlify - code syntax highlighting for your tek-tips posts[/small]

 

[psychosb]

Both codes worked perfectly!
Resumed 8 lines in one! =)

I'll try to find some awk library, so I can read more about it...

Thank you very much, feherke and Annihilannic!

Best regards!