Dd

dd is used to copy raw data from source to sink, where source and sink can be a block device, file or piped input/output.

Installation
As part of the GNU, it should be already installed with any Gentoo GNU/Linux system.

Usage
dd takes input from stdin, optionally manipulates the data, and default writes to stdout.

Examples
Some common tasks where dd is used:

Boot stick
This should work with any live media as long as the memory stick is large enough.





The default is 512 bytes but most modern devices can read/write much faster. It is possible to define different sizes for source and sink using  and.

Master boot record backup
To backup the master boot record (MBR), copy only the first 512 bytes:



Input manipulation
As an example, convert any upper case character in a file to lowercase and reverse the input per line, then pipe the output to less to display the file:



To convert lower case to upper case use.