Mount a partition from within a complete disk dump

INFILE=/path/to/your/backup.img; MOUNTPT=/mnt/foo; PARTITION=1; mount "$INFILE" "$MOUNTPT" -o loop,offset=$[ `/sbin/sfdisk -d "$INFILE" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*start=[ ]*//' | sed 's/,.*//'` * 512 ]
Suppose you made a backup of your hard disk with dd: dd if=/dev/sda of=/mnt/disk/backup.img This command enables you to mount a partition from inside this image, so you can access your files directly. Substitute PARTITION=1 with the number of the partition you want to mount (returned from sfdisk -d yourfile.img).
Sample Output
alanceil@kvirasim:22:20:1:~> /sbin/sfdisk -d disk.img
# partition table of disk.img
unit: sectors
disk.img1 : start=       63, size=   128457, Id=83
disk.img2 : start=        0, size=        0, Id= 0
disk.img3 : start=        0, size=        0, Id= 0
disk.img4 : start=        0, size=        0, Id= 0
root@kvirasim:22:20:0:~> INFILE=/home/alanceil/disk.img; MOUNTPT=/mnt/gen; PARTITION=1; mount "$INFILE" "$MOUNTPT" -o loop,offset=$[ `/sbin/sfdisk -d "$INFILE" | grep "start=" | head -n $PARTITION | tail -n1 | sed 's/.*start=[ ]*//' | sed 's/,.*//'` * 512 ]
root@kvirasim:22:22:0:~> mount | grep gen
/dev/loop0 on /mnt/gen type ext2 (rw,offset=32256)

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What Others Think

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pixelbeat · 695 weeks and 1 day ago
Why backticks? $() is your friend.
atoponce · 695 weeks ago
Sorry, I do not share your opinion that backticks are evil (and I will not get into a discussion here, this is the wrong place for that).
Alanceil · 694 weeks and 6 days ago
seofox · 32 weeks and 1 day ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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