i-love-coffee-i-love-tea/hexakt

HexDump util written in Java. Focused on creating exactly the same output as util-linux hexdump so it is possible to diff hexdumps made in java with hexdump made with the hexdump shell program.

Hex dump utility written in java

Creates output exactly formatted as util-linux's hexdump -C

Motivation

Over the years I have needed a hexdump util in java multiple times. It has helped me during development of filesystem tools, a network packet logger and binary format parsers. After more than 10 years I had a lot of different versions of this class, because

• I used it in different environments
  • Without logger
  • with slf4j
  • with direct logger usage
• I had different requirements for input and output
  • file
  • stream
  • array

To be done with this mess I generalized the class to hopefully have all required input/output combinations and with a printf method, so you have only one place to change to use a different logger or printing method.

Goals

• procudes diffable output (with util-linux hexdump -C)
• no dependencies
• drop it into your project, at most choose your logger and be done, without having to change code in multiple places

Usage

In java code

Copy the class, use one of the methods to dump the input data in hex. It has no dependencies.

Input can either come from

• byte[]
• FileInputStream
• InputStream

Output can go to

• Custom PrintStream
• System.out
• A logger that you like. You just need to insert
  • the logger import(s)
  • a line for getting a logger
  • the logger usage in HexUtil.printf

at the console (not its main purpose, but also possible)

With a file argument

`java -jar hexakt.jar filename`

With piped stdin

`cat file | java -jar hexakt.jar`

Example output

00000000  4a 61 76 61 3a 20 57 72  69 74 65 20 6f 6e 63 65  |Java: Write once|
00000010  2c 20 72 75 6e 20 61 77  61 79 2e 0a 0a           |, run away...|
0000001d