Mirror of busybox

Denys Vlasenko d6e24bd795 bc: simplify bc_array_expand() 12 hours ago
applets 2d217799e8 build system: prevent duplicate applet names 3 weeks ago
applets_sh 3778898f97 Treat custom and applet scripts as applets 1 month ago
arch 2c99702810 i386: make stack size optimization selectable, and allow i486 insns (bswap) 8 months ago
archival 71df2d3589 hush: allow hush to run embedded scripts 3 weeks ago
configs 647d8afe86 build system: remove unused CONFIG_FEATURE_HAVE_RPC 1 year ago
console-tools 43b17b1cd0 restore documentation on the build config language 6 months ago
coreutils c100535571 cat,nl: fix handling of open errors 2 weeks ago
debianutils 43b17b1cd0 restore documentation on the build config language 6 months ago
docs 71df2d3589 hush: allow hush to run embedded scripts 3 weeks ago
e2fsprogs abfa3ec059 move storage helpers to libbb.h 2 months ago
editors d08206dce1 vi: correctly detect when a deletion empties the buffer 2 weeks ago
examples 47839ae679 examples/udhcp/simple.script: add possibility to use modern "ip" 1 month ago
findutils f3e2838fc4 xargs: fix exit code if command exits nonzero, closes 11381 1 month ago
include b437df1157 inetd: suppress aliasing warning 1 week ago
init 426aff88a0 init: hopefully fix "rebooting" in containers 2 months ago
klibc-utils 43b17b1cd0 restore documentation on the build config language 6 months ago
libbb 23427a63fc lineedit: fix "defined but not used" sigaction2 warning 1 week ago
libpwdgrp 2ab9403119 whitespace and comment format fixes, no code changes 1 year ago
loginutils 4e30c67fa0 Add chroot support to chpasswd 4 months ago
mailutils 3550bc494d sendmail: use on-stack buffer for AUTH PLAIN 4 months ago
miscutils d6e24bd795 bc: simplify bc_array_expand() 12 hours ago
modutils f4fc303e36 tar: fix too eager autodetection, closes 11531 3 weeks ago
networking 6d3b4bb24d udhcpc: check that 4-byte options are indeed 4-byte, closes 11506 1 day ago
printutils 43b17b1cd0 restore documentation on the build config language 6 months ago
procps f4709d78cb free: ensure there is a least one space between numbers 3 weeks ago
qemu_multiarch_testing bddbeb82bf qemu_multiarch_testing: small improvements 1 year ago
runit 0df289f427 svlogd: fix pattern matching when using timestamps 1 month ago
scripts 71df2d3589 hush: allow hush to run embedded scripts 3 weeks ago
selinux 8f1ae25634 chcon: fix issues with recurse and retval for retained files 3 months ago
shell b437df1157 inetd: suppress aliasing warning 1 week ago
sysklogd 9d539f9fbd sysklogd: add timestamp option to ignore message timestamps 3 months ago
testsuite 55f3cab7e9 bc: fix "echo -n '#foo' | bc" not eating last 'o' 18 hours ago
util-linux 51283b8109 mdev: suppress aliasing warning 1 week ago
.gitignore 3778898f97 Treat custom and applet scripts as applets 1 month ago
.indent.pro 40bfc76385 First revision of the Busybox Style Guide and an accompanying .indent.pro 18 years ago
AUTHORS d2383f57cd paste: new applet 1 year ago
Config.in d1b2ae2d04 busybox: add '--show SCRIPT' option to display scripts 1 month ago
INSTALL ee0d4cd8cb Tweak INSTALL text 6 years ago
LICENSE af61b2a5ad LICENSE: update address of the FSF 9 years ago
Makefile 7b42f8fc76 Tweaks to build process for embedded scripts 3 weeks ago
Makefile.custom 296381ff4f applets/install: don't try to install nothing 8 months ago
Makefile.flags fa87abe807 build system: FEATURE_NSLOOKUP_BIG needs -lresolv 8 months ago
Makefile.help e4569be244 build system: "make hosttools" doesn't exist, remove it from "make help" 5 years ago
NOFORK_NOEXEC.lst 88663e481f mv: make it NOEXEC 11 months ago
NOFORK_NOEXEC.sh 6f1c942a31 NOFORK_NOEXEC.sh: a script to find "interesting" applets 11 months ago
README c77a58fb2d typo fix 3 years ago
TODO 008fc9499a libbb: remove vdprintf 1 year ago
TODO_unicode d8528b8e56 ls: unicode fixes 9 years ago
make_single_applets.sh 52c210594c fix make_single_applets.sh 1 week ago
size_single_applets.sh 36495af81f size_single_applets.sh: fix a bug which mishandles e.g. "udhcpc6" name 11 months 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