A Byte of Coding Issue 350

Merhaba,

FYI tomorrow is Valentine’s day. At least get your significant other flowers or chocolates or a lobster roll or whatever small thing they’d appreciate it. Or just forward them tomorrow’s issue of A Byte of Coding 😉 Nothing gets the magic going like deeply technical content.

Anyway, here’s the issue.

Avoiding Multiprocessing Errors in Bash Shell

Published: 12 February 2024

Tags: bash

John D. Cook concisely demonstrates how to use a mutex in a bash script that has race conditions.

Some highlights:

• creates a file as the lock

• checks for the existence of the file and creates it in one atomic operation

• it works because “the existence of a file can either be true or false and nothing else; the existence of a file is guaranteed atomicity by the OS and the filesystem”

Window: Live, Constant Time Grep

Published: 10 February 2024

Tags: rust

Alex Kladov describes the design and implementation of window, “a small grep-like utility [he] implemented in 500 lines of Rust”.

Some highlights:

• prioritizes showing some result over showing full result set

• built for processing logs with gigabytes worth of data

• you use a toml file with config options to navigate a big log file

DJI - The ART of obfuscation

Published: 6 February 2024

Tags: reverse engineering, android

Eric Le Guevel dives into how the DJI Pilot app (for drones) has had its APK code obfuscated.

Some highlights:

• first step is to find the bytecode

• encryption analysis required to decrypt DEX files

• final step is to de-obfuscate the bytecode by hijacking the Android Runtime (ART)