BusyBox: Difference between revisions

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Alpine Linux is built around musl libc and [https://www.busybox.net/ busybox]. BusyBox provides replacements for most of the utilities usually found in GNU coreutils, util-linux, etc. The utilities in BusyBox generally have fewer options than their full-featured GNU counterparts.
Alpine Linux is built around musl libc and [https://www.busybox.net/ busybox]. To minimize footprint, Alpine Linux comes with BusyBox by default. BusyBox provides replacements for most of the utilities usually found in GNU coreutils, util-linux, etc. Built-in utility programs called as applets share code for many common operations. Invoking BusyBox with no argument lists the applets that have been compiled into BusyBox binary. Refer [https://busybox.net/downloads/BusyBox.html BusyBox Manual] for options supported by BusyBox.
 
BusyBox is a multi-call binary. A multi-call binary is an executable program that performs the same job as more than one utility program. That means there is just a single BusyBox binary, but that single binary acts like a large number of utilities. This allows BusyBox to be smaller since all the built-in utility programs (called as applets) can share code for many common operations. Invoking BusyBox with no arguments, will provide with a list of the applets that have been compiled into BusyBox binary.  
 
Refer [https://busybox.net/downloads/BusyBox.html BusyBox Manual] for options supported by BusyBox.


== Ash shell ==
== Ash shell ==


Alpine Linux uses Busybox Ash for its default shell. To change the default shell to other shells like {{Pkg|bash}}, {{Pkg|zsh}}, {{Pkg|fish}} etc..refer [[Change default shell|change default shell]].
Alpine Linux uses Busybox Ash for its default shell. To change the default shell to other shells like {{Pkg|bash}}, {{Pkg|zsh}}, {{Pkg|fish}} etc..refer [[Change default shell|change default shell]].
=== Aliases ===


When using Ash shell, one can’t set aliases in the {{Path|~/.profile}}, but environment variables can be set in it. In order to use aliases with Busybox Ash, you must set the ENV environment variable to refer the aliases file.  
When using Ash shell, one can’t set aliases in the {{Path|~/.profile}}, but environment variables can be set in it. In order to use aliases with Busybox Ash, you must set the ENV environment variable to refer the aliases file.  
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{{Cat|~/.config/ash/ashrc|su{{=}}"doas -s"
{{Cat|~/.config/ash/ashrc|su{{=}}"doas -s"
}}
}}
== vi ==
Busybox uses [https://git.busybox.net/busybox/plain/editors/vi.c tiny vi], a small 'vi' clone. Refer [http://k.japko.eu/busybox-vi-tutorial.html Busybox vi tutorial] for an excellent introduction.


== Replacing BusyBox Utilities==
== Replacing BusyBox Utilities==
{{Main|How to get regular stuff working}}
{{Main|How to get regular stuff working}}
If you find certain utilities in busybox lacking in features or options, it is easy to [[How to get regular stuff working|replace]] respective busybox endpoints by their equivalent full-featured utilities.
BusyBox is set up as an endpoint for numerous symlinks that substitute various utilities.The utilities in BusyBox generally have fewer options than their full-featured GNU counterparts. If you find certain utilities in busybox lacking in features or options, it is easy to [[How to get regular stuff working|replace]] respective endpoints by their equivalent full-featured utilities.


== See Also ==
== See Also ==
* [https://www.busybox.net/ Official website]
* [https://www.busybox.net/ Official website]
* [https://busybox.net/downloads/BusyBox.html Official BusyBox Manual]
* [https://busybox.net/downloads/BusyBox.html Official BusyBox Manual]
 
* [http://k.japko.eu/busybox-vi-tutorial.html Busybox vi tutorial]
[[Category:System Administration]]
[[Category:System Administration]]

Latest revision as of 08:04, 7 November 2024

Alpine Linux is built around musl libc and busybox. To minimize footprint, Alpine Linux comes with BusyBox by default. BusyBox provides replacements for most of the utilities usually found in GNU coreutils, util-linux, etc. Built-in utility programs called as applets share code for many common operations. Invoking BusyBox with no argument lists the applets that have been compiled into BusyBox binary. Refer BusyBox Manual for options supported by BusyBox.

Ash shell

Alpine Linux uses Busybox Ash for its default shell. To change the default shell to other shells like bash, zsh, fish etc..refer change default shell.

When using Ash shell, one can’t set aliases in the ~/.profile, but environment variables can be set in it. In order to use aliases with Busybox Ash, you must set the ENV environment variable to refer the aliases file.

First create the file /etc/profile.d/profile.sh as follows:

Contents of /etc/profile.d/profile.sh

if [ -f "$HOME/.config/ash/profile" ]; then . "$HOME/.config/ash/profile" fi

Next create the file ~/.config/ash/profile as follows:

Contents of ~/.config/ash/profile

export ENV="$HOME/.config/ash/ashrc"

Now aliases can be added in the file ~/.config/ash/ashrc:

Contents of ~/.config/ash/ashrc

su="doas -s"

vi

Busybox uses tiny vi, a small 'vi' clone. Refer Busybox vi tutorial for an excellent introduction.

Replacing BusyBox Utilities

BusyBox is set up as an endpoint for numerous symlinks that substitute various utilities.The utilities in BusyBox generally have fewer options than their full-featured GNU counterparts. If you find certain utilities in busybox lacking in features or options, it is easy to replace respective endpoints by their equivalent full-featured utilities.

See Also