Busybox
lastmod 2025-11-04created 2023-12-173 edits
BusyBox is software that provides several stripped-down Unix tools in a single executable file. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, but many of the tools are designed to work with interfaces provided by the Linux kernel. It was written for embedded operating systems with very limited resources. Its authors called it the Swiss Army knife of embedded Linux, because a single executable replaces the basic functions of more than 300 individual commands. It is released as free software under the terms of the GNU GPL v2.
In short....
BusyBox is software that combines the functionality of many UNIX command-line utilities into a single executable file.
The official slogan is "The Swiss Army Knife of Embedded Linux".
Details
Because roughly the functionality of about 350 essential UNIX utilities fits into a small binary of only a few hundred KB, it is widely used in embedded environments. If you run ls -al /bin in an embedded Linux environment that uses BusyBox, you can see that many commands are symbolic links to busybox.
Of course, because of size constraints, the features each command provides are simplified, so a drawback is that quite a few features are missing compared to GNU Coreutils or the POSIX/SUS specs.
When compiling BusyBox, you can choose whether to include each command ("applet"). If you decide you don't need all 350 utilities and strip some out, you can even make a BusyBox binary of only a few tens of KB.
BusyBox is free software distributed under the GNU GPLv2.
Use cases
Mainly used when system files are corrupted. Use it like this: