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Is it possible to extract a few number of bytes out of a file using dd ? The file is located on a secondary drive.

I apologize if this is a simple question however I'm no pro at command line.

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If this is file:

hello world how are you today

Then this would extract world from file:

 dd bs=1 skip=6 count=5 if=file

It skips 6 bytes (hello_), reads 5 bytes (world), and ignores the rest.

So with skip, count, and bs=1 (or alternatively, when using GNU dd, using the count_bytes/skip_bytes flag), you can extract specific byte ranges at byte resolution.

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  • Thanks for the prompt reply. What about the 'if' and 'of' ? That is mainly my problem. I've tried dd if=/dev/sdb2/..../'directoryname' of=/dev/sdb2/..../'directoryname 2' bs=13172736b The below should extract a number of bytes out of a Virtual Machine's virtual hdd (.vmdk file), which resides in a folder called 'Windows 7 vmware' Actual text is dd if=/dev/sdb2/media/Used\ for\ VMs/ of=/media/Used\ for\ VMs/Windows\ 7\ vmware bs=13172736b – joebegborg07 Mar 7 '15 at 12:32
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    There is no /dev/sdb2/pathname... you can either write raw data to the device, or you have to use mount so it's /mnt/sdb2/pathname. This sounds like an X Y problem so maybe you should have asked your real question... – frostschutz Mar 7 '15 at 12:49

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