Swap or replace bytes in a binary file from command line

Question

There already is a beautiful trick in this thread to write bytes to binary file at desired address with dd ,is there any way to swap bytes(e.g swap 0x00 and 0xFF), or replace bytes with common tools (such as dd)?

tshiono · Accepted Answer · 2022-02-21 12:07:07Z

2

Would you please try the following:

xxd -p input_file | fold -w2 | perl -pe 's/00/ff/ || s/ff/00/' | xxd -r -p > output_file

xxd -p file dumps the binary data file in continuous hexdump style.
fold -w2 wraps the input lines by every two characters (= every bytes).
perl -pe 's/00/ff/ || s/ff/00/' swaps 00 and ff in the input string. The || logic works as if .. else .. condition. Otherwise the input 00 is once converted to ff and immediately converted back to 00 again.
xxd -r -p is the reversed version of xxd -p which converts the input hexadecimal strings into binaries.

edited Feb 21, 2022 at 12:07

answered Feb 19, 2022 at 7:55

tshiono

22.3k2 gold badges18 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nikolaii99 · Accepted Answer · 2025-01-12 05:55:30Z

1

dd has this functionality built-in via conv=swab, which "swaps every pair of input bytes". It's incredibly useful if you need to convert file formats from "byte-swapped" to "big-endian" (or vice versa):

dd if=file1.v64 of=file2.z64 conv=swab

answered Jan 12 at 5:55

Nikolaii99

12410 bronze badges

Collectives™ on Stack Overflow

Swap or replace bytes in a binary file from command line

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related