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BusyBox
The Swiss Army Knife of Embedded Linux
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 fileutils, shellutils, findutils, textutils, grep, gzip, tar, etc. BusyBox provides a fairly complete POSIX environment for any small or emdedded system. The utilities in BusyBox generally have fewer options than their full-featured GNU cousins; however, the options that are included provide the expected functionality and behave very much like their GNU counterparts.

BusyBox has been written with size-optimization and limited resources in mind. It is also extremely modular so you can easily include or exclude commands (or features) at compile time. This makes it easy to customize your embedded systems. To create a working system, just add a kernel, a shell (such as ash), and an editor (such as elvis-tiny or ae).

BusyBox is now maintained by Erik Andersen, and its ongoing development is being sponsored by Lineo.

BusyBox is licensed under the GNU GENERAL PUBLIC LICENSE

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Latest News

  • 19 April 2000 -- syslogd bugfix
    Turns out that there was still a bug in busybox syslogd. For example, with the following test app:
    	#include <syslog.h>
    
    	int do_log(char* msg, int delay)
    	{
    	    openlog("testlog", LOG_PID, LOG_DAEMON);
    	    while(1) {
    	        syslog(LOG_ERR, "%s: testing one, two, three\n", msg);
    	        sleep(delay);
    	    }
    	    closelog();
    	    return(0);
    	};
    
    	int main(void)
    	{
    	    if (fork()==0)
    	        do_log("A", 2);
    	    do_log("B", 3);
    	}
    
    it should be logging stuff from both "A" and "B". As released in 0.43 only stuff from "A" would have been logged. This means that if init tries to log something while say ppp has the syslog open, init would block (which is bad, bad, bad).

    Karl M. Hegbloom has created a fix for the problem. Thanks Karl!

  • 18 April 2000 -- BusyBox 0.43 released (finally!)
    I have finally gotten everything into a state where I feel pretty good about things. This is definitely the most stable, solid release so far. A lot of bugs have been fixed, and the following new apps have been added: sh, basename, dirname, killall, uptime, freeramdisk, tr, echo, test, and usleep. Tar has been completely rewritten from scratch. Bss size has also been greatly reduced. More details are available in the changelog. Oh, and as a special bonus, I wrote some fairly comprehensive documentation, complete with examples and full usage information.

    Many thanks go out to the fine people that have helped by submitting patches and bug reports; particularly instrumental in helping for this release were Karl Hegbloom, Pavel Roskin, Friedrich Vedder, Emanuele Caratti, Bob Tinsley, Nicolas Pitre, Avery Pennarun, Arne Bernin, John Beppu, and Jim Gleason. There were others so if I somehow forgot to mention you, I'm very sorry.

    You can grab BusyBox 0.43 tarballs here.

  • 9 April 2000 -- BusyBox 0.43 pre release
    Unfortunately, I have not yet finished all the things I want to do for BusyBox 0.43, so I am posting this pre-release for people to poke at. This contains my complete rewrite of tar, which now weighs in at 5k (7k with all options turned on) and works for reading and writing tarballs (which it does correctly for everything I have been able to throw at it). Tar also (optionally) supports the "--exclude" option (mainly because the Linux Router Project folks asked for it). This also has a pre-release of the micro shell I have been writing. This pre-release should be stable enough for production use -- it just isn't a release since I have some structural changes I still want to make.

    The pre-release can be found here. Please let me know ASAP if you find any bugs.

  • 28 March 2000 -- Andersen Baby Boy release
    I am pleased to announce that on Tuesday March 28th at 5:48pm, weighing in at 7 lbs. 12 oz, Micah Erik Andersen was born at LDS Hospital here in Salt Lake City. He was born in the emergency room less then 5 minutes after we arrived -- and it was such a relief that we even made it to the hospital at all. Despite the fact that I was driving at an amazingly unlawful speed and honking at everybody and thinking decidely unkind thoughts about the people in our way, my wife (inconsiderate of my feelings and complete lack of medical training) was lying down in the back seat saying things like "I think I need to start pushing now" (which she then proceeded to do despite my best encouraging statements to the contrary).

    Anyway, I'm glad to note that despite the much-faster-than-we-were-expecting labor, both Shaunalei and our new baby boy are doing wonderfuly.

    So now that I am done with my excuse for the slow release cycle... Progress on the next release of BusyBox has been slow but steady. I expect to have a release sometime during the first week of April. This release will include a number of important changes, including the addition of a shell, a re-write of tar (to accomodate the Linux Router Project), and syslogd can now accept multiple concurrent connections, fixing lots of unexpected blocking problems.

  • 11 February 2000 -- BusyBox 0.42 released
    This is the most solid BusyBox release so far. Many, many bugs have been fixed. See the changelog for details. Of particular interest, init will now cleanly unmount filesystems on reboot, cp and mv have been rewritten and behave much better, and mount and umount no longer leak loop devices. Many thanks go out to Randolph Chung, Karl M. Hegbloom, Taketoshi Sano, and Pavel Roskin for their hard work on this release of BusyBox. Please pound on it and let me know if you find any bugs.

  • 19 January 2000 -- BusyBox 0.41 released
    This release includes bugfixes to cp, mv, logger, true, false, mkdir, syslogd, and init. New apps include wc, hostid, logname, tty, whoami, and yes. New features include loop device support in mount and umount, and better TERM handling by init. The changelog can be found here.

  • 7 January 2000 -- BusyBox 0.40 released
    This release includes bugfixes to init (now includes inittab support), syslogd, head, logger, du, grep, cp, mv, sed, dmesg, ls, kill, gunzip, and mknod. New apps include sort, uniq, lsmod, rmmod, fbset, and loadacm. In particular, this release fixes an important bug in tar which in some cases produced serious security problems. As always, the changelog can be found here.

  • 11 December 1999 -- BusyBox Website
    I have received permission from Bruce Perens (the original author of BusyBox) to set up this site as the new primary website for BusyBox. This website will always contain pointers to the latest and greatest, and will also contain the latest documentation on how to use BusyBox, what it can do, what arguments its apps support, etc.

  • 10 December 1999 -- BusyBox 0.39 released
    This release includes fixes to init, reboot, halt, kill, and ls, and contains the new apps ping, hostname, mkfifo, free, tail, du, tee, and head. A full changelog can be found here.

  • 5 December 1999 -- BusyBox 0.38 released
    This release includes fixes to tar, cat, ls, dd, rm, umount, find, df, and make install, and includes new apps syslogd/klogd and logger.
Documentation
Current documentation for BusyBox includes:
  • BusyBox.html This is a list of the all the available commands in BusyBox with complete usage information and examples of how to use each app. I spent a lot of time updating these docs and trying to make them fairly comprehensive for the BusyBox 0.43 release. If you find any errors (factual, grammatical, whatever) please let me know.
  • More documentation will follow.
Related Software
  • ash is a very small Bourne shell. If you need a shell for your embedded systems, this is it.

  • ae is a tiny full-screen text editor with both modal (vi-like) and modeless (emacs-like) modes, determined by an ae.rc config file. It makes a nice editor if people that don't know "vi" will need to work on your embedded system.

  • elvis-tiny is based on a 1991 Minix version of the elvis "vi" clone. It behaves as one would expect a minamalist vi to behave, and is very small.

  • nano A small GPLed pico clone that makes a nice editor for people that don't know "vi".

  • iproute Much more flexible replacement for ifconfig, route, etc. It is quite small, and for most networking applications, it is all you need. It also provides support for extremely advanced networking and provides Quality of Service(QoS) support, but most people will just need to use the "ip" command and will not even need to install the rest.

  • Pump This is the DHCP/BOOTP client written by RedHat. When compiled properly, it gives you dhcp client support for about 35k.

  • sash The Stand Alone SHell. This is a small shell (not Bourne shell compatable) that is similar to busybox in that it provides a number of common utilities as built-ins.

  • NewLib This is a small C library intended for use on embedded systems. If you are finding GNU libc is a bit too big for your applications, try NewLib and it may help.

  • asmutils asmutils is similar to BusyBox in that it provides a number of common application for embedded systems that are very tiny. In fact, they are a _lot_ smaller than the equivalent apps in busybox -- but the price you pay for the size is reduced portability (x86 only) and interfaces that are tied directly to a perticular kernel (no libc involved).

  • TinyLogin is a nice embedded tool for handling authentication, changing passwords, and similar tasks, and which nicely complements BusyBox.

Projects using BusyBox
I know of the following projects that use BusyBox Do you use BusyBox? I'd love to know about it and I'd be happy to link to you.
Important Links


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The Busybox logo is copyright 1999,2000, Erik Andersen.
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