Replace hex in binary file with shell without sed

Question

I have binary file that I want to replace with shell script 0xaa,0xbb,0xcc,0xdd with 0x11,0x22,0x33,0x44

I can get 0xaa,0xbb,0xcc,0xdd into shell script like $1 but how can I replace it with 0x11,0x22,0x33,0x44 without sed?

Answer 1

You could create a bash script that does a hexdump of your file, a simple replace and then convert back to a binary file.

You could use an application such as xxd, or hexdump to create a hex dump of your file. This is explained here: convert binary data to hex in shell script?

It looks like xxd creates a hex string that looks like this "aabbccdd" rather than your "0xaa,0xbb,0xcc,0xdd" so watch out for that!

To find out how to do a replace, you could look at this answer: Find and Replace Inside a Text File from a Bash Command

You would then want to convert the HEX string back into binary, which is explained here: linux shell scripting: hex string to bytes