topic Re: Extract fields from text file. in Operating System - Linux

Extract fields from text file.

Rajesh SB — Wed, 02 May 2007 07:27:40 GMT

Hi Experts,

I have df -k output text
Can any body help me in extracting last 2 column fields(Space Separator) from below text irrespective of no. of coloumns.

mpfs 38G 0K 38G 0% /dev/vx/rdmp
swap 38G 356M 38G 1% /tmp
/dev/vx/dsk/bootdg/opt
32G 15G 17G 48% /opt
/dev/vx/dsk/tempbackup_DG/tempvol
200G 8.6G 179G 5% /tempbackup
/dev/vx/dsk/dbaarch_DG/dbaarch_data_Vol6
98G 28G 69G 29% /opt/oraclea/arch
/dev/vx/dsk/dbabckp_DG/dbabckp_data_Vol5
100G 25G 75G 25% /opt/oraclea/backup
/dev/vx/dsk/dba_DG/dba_data_Vol2
50G 48G 1.6G 97% /opt/oraclea/mnt2

Any tips.

Thanks & Regards,
Rajesh SB

Re: Extract fields from text file.

Piergiacomo Perini — Wed, 02 May 2007 07:30:32 GMT

Hi Rajesh SB,
try this
df -k > dfk.txt
awk â Fâ â â { print $5, $6 }â dfk.txt

regards
pg

Re: Extract fields from text file.

Wouter Jagers — Wed, 02 May 2007 07:34:43 GMT

Hi,

This seems to work overhere:

# cat file.txt | awk '{FROM=(NF-2);print $FROM,$(FROM+1),$NF}'

--> returns 3 last fields.

Cheers,
Wout

Re: Extract fields from text file.

Rajesh SB — Wed, 02 May 2007 07:37:30 GMT

Thanks PG for quick response.

Some of the lines are having 6 columns and some are with 5 columns.

I am particularly looking for mount-point and percentage columns.

You command won't work.
Any other tips.

Regards,
Rajesh

Re: Extract fields from text file.

James R. Ferguson — Wed, 02 May 2007 07:40:47 GMT

Hi:

# awk '{print $NF,$(NF-1)}' file

Regards!

...JRF...

Re: Extract fields from text file.

Peter Nikitka — Wed, 02 May 2007 07:41:03 GMT

Hi,

I would add a check to send output only when there are more than 2 columns - this will deal correctly with the bdf output for long device names:

bdf -l | awk 'NF>2 {print $(NF-1),$NF}'

mfG Peter

Re: Extract fields from text file.

Rajesh SB — Wed, 02 May 2007 07:52:31 GMT

Thanks Peter,
You command is working fine.
Highly appreciate your timely response.

Case-1 Not Worked
cat df-k.op| awk '{FROM=(NF-2);print $FROM,$(FROM+1),$NF}'
awk: The field -1 must be in the range 0 to 199.

The input line number is 2.
The source line number is 1.

Case-2 Not worked:
cat df-k.op|grep -v Filesystem| awk '{FROM=(NF-2);print $FROM,$(FROM+1),$NF}'

Thanks to you all for quick response again

Thanks & Regards,

Re: Extract fields from text file.

James R. Ferguson — Wed, 02 May 2007 07:56:09 GMT

Hi (again) Rajesh:

Avoid the extra 'cat' process just to read a file. Instead of :

# cat myfile | awk '...'

...simply do:

# awk '...' myfile

Regards!

...JRF...

Re: Extract fields from text file.

Wouter Jagers — Wed, 02 May 2007 08:01:25 GMT

Very true, I should learn not posting that.

(you know how it goes: make a sample file, cat it to check, use command history and start piping..)

Also, sorry for confusing the numbers two and three. That should not happen too often or I'm going to get myself in trouble one day :-)

Cheers

Re: Extract fields from text file.

Rajesh SB — Wed, 02 May 2007 08:11:22 GMT

Thanks James for your tips on effecting scripting.
It is good to avoid unnecessary extra command usage.

Learning is never ending process!

Cheers,
Rajesh

Re: Extract fields from text file.

Rajesh SB — Thu, 03 May 2007 04:31:05 GMT

Hi,

I am able to extract the last 2 coloumn using below awk command.

# bdf -l | awk 'NF>2 {print $(NF-1),$NF}'

Cheers,
Rajesh SB