Mirror of busybox

Denys Vlasenko 5f84c56336 awk: fix backslash handling in sub() builtins 3 days ago
applets 1a45b2ccea fix "warning array subscript has type 'char'" 2 years ago
applets_sh 981b2eff81 mim: run scripts from a specification file 3 years ago
arch fad8d6b6c0 build system: combat gcc zealotry in data alignment, now for x86_64 too 2 years ago
archival 2f663a6f7d cpio: tweak --help 3 weeks ago
configs d32ef3174b *: remove remains of FEATURE_TOUCH_NODEREF 1 year ago
console-tools 99476502f9 Remove "select PLATFORM_LINUX" 6 months ago
coreutils 6d9427420b od: -l,I,L indeed depend on sizeof(long), fix this 1 week ago
debianutils db5546ca10 libbb: code shrink: introduce and use [_]exit_SUCCESS() 1 year ago
docs 4642cf5b38 tsort: new applet 1 year ago
e2fsprogs 987be932ed *: slap on a few ALIGN_PTR where appropriate 1 year ago
editors 5f84c56336 awk: fix backslash handling in sub() builtins 3 days ago
examples c5682813ab examples/var_service/README: fix an error 2 weeks ago
findutils d8a3360380 find: implement -ok 2 months ago
include 9225f9684f libbb/dump: make xxd_displayoff member conditional on xxd 1 week ago
init a26711a2d1 libbb: consolidate NOMMU fix of restoring high bit in argv[0][0] 2 months ago
klibc-utils 99476502f9 Remove "select PLATFORM_LINUX" 6 months ago
libbb 9790eb73c8 libbb/dump: code shrink 1 week ago
libpwdgrp 0cdd6f5792 libbb: fix fallout from nth_string() robustification, closes 14726 1 year ago
loginutils 931c55f9e2 libbb: invert the meaning of SETUP_ENV_NO_CHDIR -> SETUP_ENV_CHDIR 1 year ago
mailutils 94c78aa0b9 config system: move some options closer to relevalnt tool subdirectories 1 year ago
miscutils cb57abb46f seedrng: fix for glibc <= 2.24 not providing random header 1 month ago
modutils af5277f883 modprobe: call finit_module with MODULE_INIT_COMPRESSED_FILE if module name doesn't end with .ko 2 months ago
networking fe0b798548 tunctl: code shrink 1 week ago
printutils 9b6f44e040 style fix 1 year ago
procps c6058d221a nmeter: improve %T fractionals display 4 weeks ago
qemu_multiarch_testing bddbeb82bf qemu_multiarch_testing: small improvements 6 years ago
runit db5546ca10 libbb: code shrink: introduce and use [_]exit_SUCCESS() 1 year ago
scripts 2d4a3d9e6c fixdep: avoid underflow when end of entry doesn't coincide with EOF 3 months ago
selinux 987be932ed *: slap on a few ALIGN_PTR where appropriate 1 year ago
shell b5be8da350 hush: make "false" built-in 1 week ago
sysklogd 99476502f9 Remove "select PLATFORM_LINUX" 6 months ago
testsuite 5f84c56336 awk: fix backslash handling in sub() builtins 3 days ago
util-linux d7814f5727 hexdump: code shrink 1 week ago
.gitignore 3778898f97 Treat custom and applet scripts as applets 4 years ago
.indent.pro 40bfc76385 First revision of the Busybox Style Guide and an accompanying .indent.pro 23 years ago
AUTHORS 20a4f70eca tree: new applet 11 months ago
Config.in 465f05a420 build system: fix "Config.in:117 error: Overlong line" 4 weeks ago
INSTALL ee0d4cd8cb Tweak INSTALL text 11 years ago
LICENSE af61b2a5ad LICENSE: update address of the FSF 14 years ago
Makefile 7c1f975cdd build system: clean more files on make clean 1 month ago
Makefile.custom 296381ff4f applets/install: don't try to install nothing 5 years ago
Makefile.flags 40fa8eb998 build system: Make it possible to build with 64bit time_t 4 weeks ago
Makefile.help e4569be244 build system: "make hosttools" doesn't exist, remove it from "make help" 9 years ago
NOFORK_NOEXEC.lst 88663e481f mv: make it NOEXEC 5 years ago
NOFORK_NOEXEC.sh 6f1c942a31 NOFORK_NOEXEC.sh: a script to find "interesting" applets 5 years ago
README c77a58fb2d typo fix 8 years ago
TODO 008fc9499a libbb: remove vdprintf 5 years ago
TODO_unicode d8528b8e56 ls: unicode fixes 13 years ago
busybox_ldscript.README.txt 33a9f34df5 add busybox_ldscript.README.txt 1 year ago
make_single_applets.sh b02f8ca909 make_single_applets.sh: switch off nologin deps option 2 years ago
size_single_applets.sh df1ff103c9 config: add size information for three more applets 4 years ago


Please see the LICENSE file for details on copying and usage.
Please refer to the INSTALL file for instructions on how to build.

What is busybox:

BusyBox combines tiny versions of many common UNIX utilities into a single
small executable. It provides minimalist replacements for most of the
utilities you usually find in bzip2, coreutils, dhcp, diffutils, e2fsprogs,
file, findutils, gawk, grep, inetutils, less, modutils, net-tools, procps,
sed, shadow, sysklogd, sysvinit, tar, util-linux, and vim. The utilities
in BusyBox often have fewer options than their full-featured cousins;
however, the options that are included provide the expected functionality
and behave very much like their larger counterparts.

BusyBox has been written with size-optimization and limited resources in
mind, both to produce small binaries and to reduce run-time memory usage.
Busybox is also extremely modular so you can easily include or exclude
commands (or features) at compile time. This makes it easy to customize
embedded systems; to create a working system, just add /dev, /etc, and a
Linux kernel. Busybox (usually together with uClibc) has also been used as
a component of "thin client" desktop systems, live-CD distributions, rescue
disks, installers, and so on.

BusyBox provides a fairly complete POSIX environment for any small system,
both embedded environments and more full featured systems concerned about
space. Busybox is slowly working towards implementing the full Single Unix
Specification V3 (http://www.opengroup.org/onlinepubs/009695399/), but isn't
there yet (and for size reasons will probably support at most UTF-8 for
internationalization). We are also interested in passing the Linux Test
Project (http://ltp.sourceforge.net).


Using busybox:

BusyBox is extremely configurable. This allows you to include only the
components and options you need, thereby reducing binary size. Run 'make
config' or 'make menuconfig' to select the functionality that you wish to
enable. (See 'make help' for more commands.)

The behavior of busybox is determined by the name it's called under: as
"cp" it behaves like cp, as "sed" it behaves like sed, and so on. Called
as "busybox" it takes the second argument as the name of the applet to
run (I.E. "./busybox ls -l /proc").

The "standalone shell" mode is an easy way to try out busybox; this is a
command shell that calls the built-in applets without needing them to be
installed in the path. (Note that this requires /proc to be mounted, if
testing from a boot floppy or in a chroot environment.)

The build automatically generates a file "busybox.links", which is used by
'make install' to create symlinks to the BusyBox binary for all compiled in
commands. This uses the CONFIG_PREFIX environment variable to specify
where to install, and installs hardlinks or symlinks depending
on the configuration preferences. (You can also manually run
the install script at "applets/install.sh").


Downloading the current source code:

Source for the latest released version, as well as daily snapshots, can always
be downloaded from


You can browse the up to the minute source code and change history online.


Anonymous GIT access is available. For instructions, check out:


For those that are actively contributing and would like to check files in,


The developers also have a bug and patch tracking system
(https://bugs.busybox.net) although posting a bug/patch to the mailing list
is generally a faster way of getting it fixed, and the complete archive of
what happened is the git changelog.

Note: if you want to compile busybox in a busybox environment you must


Getting help:

when you find you need help, you can check out the busybox mailing list
archives at http://busybox.net/lists/busybox/ or even join
the mailing list if you are interested.



if you find bugs, please submit a detailed bug report to the busybox mailing
list at busybox@busybox.net. a well-written bug report should include a
transcript of a shell session that demonstrates the bad behavior and enables
anyone else to duplicate the bug on their own machine. the following is such
an example:

to: busybox@busybox.net
from: diligent@testing.linux.org
subject: /bin/date doesn't work

package: busybox
version: 1.00

when i execute busybox 'date' it produces unexpected results.
with gnu date i get the following output:

$ date
fri oct 8 14:19:41 mdt 2004

but when i use busybox date i get this instead:

$ date
illegal instruction

i am using debian unstable, kernel version 2.4.25-vrs2 on a netwinder,
and the latest uclibc from cvs.


note the careful description and use of examples showing not only what
busybox does, but also a counter example showing what an equivalent app
does (or pointing to the text of a relevant standard). Bug reports lacking
such detail may never be fixed... Thanks for understanding.



Busybox is developed and tested on Linux 2.4 and 2.6 kernels, compiled
with gcc (the unit-at-a-time optimizations in version 3.4 and later are
worth upgrading to get, but older versions should work), and linked against
uClibc (0.9.27 or greater) or glibc (2.2 or greater). In such an
environment, the full set of busybox features should work, and if
anything doesn't we want to know about it so we can fix it.

There are many other environments out there, in which busybox may build
and run just fine. We just don't test them. Since busybox consists of a
large number of more or less independent applets, portability is a question
of which features work where. Some busybox applets (such as cat and rm) are
highly portable and likely to work just about anywhere, while others (such as
insmod and losetup) require recent Linux kernels with recent C libraries.

Earlier versions of Linux and glibc may or may not work, for any given
configuration. Linux 2.2 or earlier should mostly work (there's still
some support code in things like mount.c) but this is no longer regularly
tested, and inherently won't support certain features (such as long files
and --bind mounts). The same is true for glibc 2.0 and 2.1: expect a higher
testing and debugging burden using such old infrastructure. (The busybox
developers are not very interested in supporting these older versions, but
will probably accept small self-contained patches to fix simple problems.)

Some environments are not recommended. Early versions of uClibc were buggy
and missing many features: upgrade. Linking against libc5 or dietlibc is
not supported and not interesting to the busybox developers. (The first is
obsolete and has no known size or feature advantages over uClibc, the second
has known bugs that its developers have actively refused to fix.) Ancient
Linux kernels (2.0.x and earlier) are similarly uninteresting.

In theory it's possible to use Busybox under other operating systems (such as
MacOS X, Solaris, Cygwin, or the BSD Fork Du Jour). This generally involves
a different kernel and a different C library at the same time. While it
should be possible to port the majority of the code to work in one of
these environments, don't be surprised if it doesn't work out of the box. If
you're into that sort of thing, start small (selecting just a few applets)
and work your way up.

In 2005 Shaun Jackman has ported busybox to a combination of newlib
and libgloss, and some of his patches have been integrated.

Supported hardware:

BusyBox in general will build on any architecture supported by gcc. We
support both 32 and 64 bit platforms, and both big and little endian

Under 2.4 Linux kernels, kernel module loading was implemented in a
platform-specific manner. Busybox's insmod utility has been reported to
work under ARM, CRIS, H8/300, x86, ia64, x86_64, m68k, MIPS, PowerPC, S390,
SH3/4/5, Sparc, and v850e. Anything else probably won't work.

The module loading mechanism for the 2.6 kernel is much more generic, and
we believe 2.6.x kernel module loading support should work on all
architectures supported by the kernel.


Please feed suggestions, bug reports, insults, and bribes back to the busybox
mailing list:


and/or maintainer:

Denys Vlasenko