fdisk command, for / value / do

linuxchump · 03-11-2005, 11:49 PM

I've been parsing the posts here and have found some valuable information. But I'm still lost on something. I'm wanting to write a script that will identify Linux filesystems. Essentially, I was thinking of using 'fdisk' and 'mount' to obtain this information.

'fdisk -l' lists recognized partitions and a 'System Type' field (value of 'Linux' is the one I'm concerned with).

'mount -vf --guess-fstype' allows me to use 'mount' to guess the FS TYPE for a partition, without actually mounting it.

My thought was to parse the output of 'fdisk -l' and look only for entries containing 'Linux', and then run the 'mount' command above against each of those to report the Linux FS TYPE on the filesystem/partition.

I've tried IFs, FOR, and LOOPS. Nada. Zilch. I'm beyond lame at this point. I know what I want, but I'm stuck getting there. A variable could be 'type', and set that to 'Linux'. So if the output of fdisk is equal to that I want to execute the mount command. The most success has been with IF statement,

#!/bin/bash
#
#

type=Linux

if [ 'fdisk -l' = $type ]; then
mount -vf --guess-fstype > output_file
fi

Does anyone have any thoughts on the best route to take here, in writing a bash script to identify the FS TYPE for a partition?

LC

dbalsige · 03-12-2005, 01:12 AM

hello

the option --guess-vfstype requires an argument
so what you might use is something like:

#!/bin/sh

guess_fs()
{
local IFS=$'\n'
for LINE in `fdisk -l | grep Linux` ; do
mount -vf --guess-fstype ${LINE%% *}
done
}

guess_fs

linuxchump · 03-12-2005, 10:01 PM

Hi dbalsige and all,

I see your hint and it works good. I get output;

[root@chump tmp]# ./reiser_2.sh
ext2
ext3
reiserfs
ext2
ext3
swap
[root@chump tmp]#

I have two goals though I'm working through.

ONE: Associate the device (partition) with the FS TYPE guessed by mount. (Output of FS TYPE isn't associated with any device above.)

TWO: If the FS TYPE returned is equal ot 'reiserfs' I want to run another command against that (those) reiserfs partition(s).

I'm going to work with your tip above and see where I go. Report back more soon. Thank you kindly.

LC

linuxchump · 03-12-2005, 10:37 PM

I'm a step further in my quest, in that I now use;

#!/bin/sh

guess_fs()
{
local IFS=$'\n'
for LINE in `fdisk -l | grep Linux` ; do
blkid -c /dev/null ${LINE%% *} | grep reiser
done
}

guess_fs

That now returns more meaningful information;

[root@chump tmp]# ./reiserid.sh
/dev/sda4: LABEL="reisfs" TYPE="reiserfs"

Now for goal TWO, taking any of the reisefs identified partitions and running a command against them.

I want to run 'losetup' against reiserfs partitions. Associate each partition with a loop device. I'm wondering if I can take the output returned from part one and use that for part two?

Of course this calls for finding available loop device and associating partition with it.

I'm thinking, should I redirect the output from what I have above to a file and then parse this file for devices (/dev/hd*, /dev/sd*) and associate them to loop?

Thank you kindly,

LC

gbonvehi · 03-13-2005, 05:56 AM

I didn't understand what you're really trying to achieve, but hope this helps:

Code:

#!/bin/sh
                                                                                          
guess_fs()
{
local IFS=$'\n'
for LINE in `fdisk -l | grep Linux` ; do
    if blkid -c /dev/null ${LINE%% *} | grep reiser >/dev/null; then
        yourcommands;
    fi
done
}
                                          
guess_fs