Problem replacing text in a script

[Gus Mestousis]

I am trying to write a script that gets the value of the logival volume an application is on and then adds an r after the volume group so that I can run fsadm on it.
Somthing along the lines of cat /etc/fstab |grep $APPHOME |awk '{ print $1 }' sed ?????

How would I insert the "r" into /dev/vg01/lvol6, sometimes clients use different naming conventions ... /dev/vg02/appname

Thanks!

[Sridhar Bhaskarla]

I would do the following quickly -

....
...
for ENTRY in $(grep $APPHOME /etc/fstab|awk '{print $1}')
do
LVOL=$(echo $ENTRY|awk '{FS="/";print $4}')
RLVOL=$(echo $ENTRY|sed 's/'$LVOL'/r'$LVOL'/')
echo $RLVOL
done

-Sri

[Rajeev Shukla]

Other simple one would be
LVOL=`cat /etc/fstab|grep $APPHOME|awk -F / '{print $4}'`
VG=`cat /etc/fstab|grep $APPHOME|awk -F / '{print $3}'`

And when you want to substitute with 'r' you can do it

RLVOL=/dev/${VG}/r${LVOL}

cheers
Rajeev

[john korterman]

Hi Gus,

you could use the korn shell's built-in functions for string handling, e.g.:

#!/usr/bin/sh

APPHOME=$1

cat /etc/fstab | grep $APPHOME | while read line
do
LVOL=`echo $line | awk '{print $1}'`
ENDING=`basename $LVOL`
BEGINNING="${LVOL%%$ENDING}"
echo ${BEGINNING}r${ENDING}
done
~
regards,
John K.

[Robin Wakefield · Accepted solution]

Hi Gus,

grep $APPHOME /etc/fstab | awk '{print $1}' | sed 's+.*/+&r+'

Rgds, Robin

[F. X. de Montgolfier]

Hi,

bdf gives you the name of the lv your application is using.

I prefer using bdf to grepping it from fstab, as it will give you the logical volume the application is installed on even if it is sharing its logical volume...

#[SAVE]> bdf /tmp/test/
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol4 1024000 40785 921815 4% /tmp

The following command should, (though there might be tyops: I don't have access to my system fron here), give you the correct answer:

bdf $APPHOME |grep /dev/ |sed 's!(\^[^ ]+/\)!\1r!'|awk '{print $1}'

The bdf part will give you the logical volume on which your application resides, the grep will ensure that only the relevant line is printed, the sed will find the longest string containing a '/' since the begining of the line, and add 'r'after it, and the awk will print only the first argument...

I won't promise that the command is _fast_, though ;-)

Cheers,

Fran??ois-Xavier

[H.Merijn Brand (procura]

a5:/ 108 # grep -v nfs /etc/fstab
/dev/vg00/lvol3 / vxfs delaylog 0 1
/dev/vg00/lvol1 /stand hfs defaults 0 1
/dev/vg00/tmp /tmp vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/vg00/lvol7 /usr vxfs delaylog 0 2
/dev/vg00/var /var vxfs delaylog 0 2
/dev/vg00/opt /opt vxfs delaylog 0 2
/dev/vg00/home /home vxfs delaylog 0 2
/dev/vg00/u /u vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/vg00/pro /pro vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/vg00/data /data vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/vg00/wrk /wrk vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/cd0 /cdrom cdfs ro,rr,noauto 0 0
a5:/ 109 # echo $APPHOME
/pro
a5:/ 110 # perl -nle'/$ENV{APPHOME}/&&s:\s.*::&&s:vg\d+/:$&r:&&print' /etc/fstab
/dev/vg00/rpro
a5:/ 111 #

[F. X. de Montgolfier]

Sorry, following up on myself...

I don't know why I insisted on using awk when sed is enough for the job...
Let's try doing it right this time:

bdf $APPHOME |grep /dev/ |sed 's!(\^[^ ]+/\)(\[^ ]+\).+!\1r\2!'

- ^[^ ]+/ should give you the basename of your logical volume,
- [^ ]+ should give you the logical volume name,
- the .+ is there to engulf all the rest of the line

Please remember that this is untested, as I don't have access to my platform. It should be near the mark, though...

Cheers,

Fran??ois-Xavier

[Gus Mestousis]

Thanks for all the great replies.

Enjoy your holidays!

Gus

[Steven E. Protter]

Attached is a perl script that handles this based on creating filelists. Be careful using it on /etc files,but it works, is easy to modify and understand.

It actually uses sed btw.

Steve

[H.Merijn Brand (procura]

Ahhhhhhrgggggg, someone still using perl4!

Never use this, not even as an example.
And *if* you need using perl4, at least add -w to the command line.

When converting this to perl5, start with something like

#!/usr/local/bin/perl

use strict;
use warnings;
use File::Find;
use Sys::Hostname;

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