How to transform hexadecimal information to binary using a Linux command

In Linux systems, converting hexadecimal data to binary data can be achieved using a series of command-line tools. A commonly used tool is xxd, which facilitates conversion between hexadecimal and binary formats. Below are the specific steps and examples:

Step 1: Create Hexadecimal Data

First, prepare some hexadecimal data. For instance, consider the following hexadecimal values:

shell
1a2b3c4d

Save this data to a file, such as hexdata.txt.

Step 2: Convert to Binary Using xxd

The xxd command can generate hexadecimal dumps or convert hexadecimal data to binary files. To perform the conversion, use the -r and -p options: -r specifies conversion from hexadecimal, while -p enforces a plain hexadecimal format without additional formatting.

Execute the following command:

bash
xxd -r -p hexdata.txt binarydata

This command reads the hexadecimal data from hexdata.txt and converts it to binary data, writing the output to binarydata.

Step 3: Inspect the Binary File

To view the contents of binarydata, use xxd for its hexadecimal representation or od (octal dump) for binary content:

bash
xxd binarydata

or

bash
od -t x1 binarydata

Example

Suppose hexdata.txt contains the following hexadecimal data:

shell
echo "1a2b3c4d" > hexdata.txt

Apply the conversion command:

bash
xxd -r -p hexdata.txt binarydata

Then inspect the converted binary file:

bash
xxd binarydata

The output may appear as:

shell
00000000: 1a2b 3c4d                                .+<M

This confirms that the hexadecimal data 1a2b3c4d has been successfully converted to binary format.

By following this process, you can efficiently convert any hexadecimal data to binary data, which is particularly valuable for handling binary files and data analysis tasks.