Difference between revisions of "Busybox replacement"

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(Add Beastiebox here as well; argument for using mksh as shell)
(Move the toybox material to a page where some project that wants to bring BSD's fsck_ffs and pfctl to Android won't randomly insert itself before everything else.)
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This page has information about the commands and features desired for a busybox replacement program.
The Toybox material has moved to http://landley.net/toybox/roadmap.html
See [[Busybox replacement project]] for the project proposal for this work.
== Command List ==
We have several potential use cases for a busybox replacement, and are using those to determine a consensus on which commands to target for a 1.0 release of an unencumbered busybox replacement package.
Our current candidate list combines the commands toybox already implements, the development environment command list, the toolbox standard commands, the Sony configuration of busybox, and the selected subset of the SUSv4 standard.
Thus the first release of a busybox replacement should include the following commands:
  at awk basename bc bunzip2 bzcat bzip2 cal cat catv chgrp chmod
  chown chroot chvt cksum cmp comm count cp cpio csplit cut date dd df
  diff dirname dmesg dnsdomainname du echo egrep env expand expr
  false fgrep file find fold freeramdisk ftpd ftpget ftpput fuser
  getconf getty grep gunzip gzip halt hd head help hostname id
  ifconfig iftop init insmod install ioctl ionice join kill
  killall klogd less link ln logger login logname losetup ls lsmod
  lsof man md5sum mdev mkdir mkfifo mknod mkswap mktemp modprobe
  more mount mountpoint mv nc netcat netstat newgrp newfs_msdos
  nice nl nohup notify od oneit paste patch pathchk pgrep pidof
  ping ping6 pivot_root pkill poweroff printenv printf ps pwd
  readlink reboot renice rm rmdir rmmod route sed seq setsid
  sfdisk sh sha1sum sleep sort split start stat stop stty swapoff
  swapon switch_root sync syslogd tabs tac tail tar taskset tee
  telnet telnetd test time top touch tput tr true truncate tty
  umount uname unexpand uniq unlink unshare uptime usleep uudecode
  uuencode vconfig vi vmstat wc wget which who whoami xargs yes
Plus additional to-be-determined shell functionality.
== Beastiebox currently implements ==
== Beastiebox currently implements ==
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Tab completion, Korn Shell scripting features ('''[[''', arrays, etc). and is
Tab completion, Korn Shell scripting features ('''[[''', arrays, etc). and is
actively developed on its own.
actively developed on its own.
== Toybox currently implements ==
Here's a link to the toybox project: http://www.landley.net/toybox/about.html
which is a prime candidate for replacing busybox.
The triaged toybox (2 clause BSD license) is currently implementing usable versions of:
  bzcat cal cat catv chroot chvt cksum count cp df dirname dmesg
  echo false help link mkswap nc netcat nice nohup oneit patch pwd
  rmdir seq setsid sha1sum sleep sort sync tee true truncate tty
  uname unlink unshare wc which yes
And contains partial implementations of:
  mdev sh
See [http://landley.net/code/toybox/todo.txt the Toybox todo list] for the most up to date status.
== Use case: provide a self-hosting development environment ==
The following commands are enough to build the Aboriginal Linux development environment, boot it to a shell prompt, and build Linux From Scratch 6.8 under it.  (Aboriginal Linux currently uses BusyBox for this, thus provides a corresponding test environment for toybox.)
This use case includes running init scripts and other shell scripts, running configure, make, and install in each package, and providing basic command line facilities such as a text editor.  (It does not include a compiler toolchain or C library, those are outside the scope of this project.)
=== Already in toybox ===
  bzcat cat cp dirname echo patch rmdir sha1sum sleep sort sync
  true uname wc which yes env
=== Additional commands for development environment ===
  zcat awk basename bzip2 chmod chown cmp cut date dd diff
  egrep expr find grep gzip head hostname id install ln ls
  mkdir mktemp mv od readlink rm sed sh tail tar touch tr uniq
  wget whoami xargs chgrp comm gunzip less logname man split
  tee test time bunzip2 chgrp chroot comm cpio dmesg
  dnsdomainname ftpd ftpget ftpput gunzip ifconfig init less
  logname losetup man mdev mount mountpoint nc pgrep pkill
  pwd route split stat switch_root tac tee test time umount vi
Note: Aboriginal Linux installs bash 2.05b as #!/bin/sh and its scripts require bash extensions not present in busybox ash.
== Use case: replacing Toolbox commands ==
=== Full toolbox command set ===
Here is the full list of toolbox commands:
cat chmod chown cmp cp
date dd df dmesg getevent
getprop        hd id ifconfig iftop
insmod ioctl kill ln log
ls lsmod mkdir mount mv
netstat newfs_msdos notify pidof printenv
ps renice rm rmdir rmmod
route schedtop sendevent setconsole setprop
sleep smd start stop sync
toolbox top umount vmstat watchprops
=== Standard commands ===
Toolbox in Android (what version?) implements the following standard commands:
cat chmod chown cmp cp date dd df dmesg
id ifconfig iftop insmod ioctl ionice
kill ln ls lsmod lsof
mkdir mount mv netstat newfs_msdos notify
ps printenv reboot renice rm rmdir rmmod route
sleep start stop sync top umount uptime vmstat
=== Android-specific commands ===
Toolbox also provides the following nonstandard commands, which are unique to Android (or at least do not appear in Ubuntu or
  alarm hd getevent getprop ioctl log nandread notify
  r schedtop sendevent setconsole setprop smdwatchprops wipe
== Busybox commands ==
=== default 1.10 build ===
A default build of Busybox 1.10 has the following commands:
[, [[, addgroup, adduser, adjtimex, ar, arp, arping, ash,
awk, basename, bunzip2, bzcat, bzip2, cal, cat, catv,
chattr, chgrp, chmod, chown, chpasswd, chpst, chroot,
chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond,
crontab, cryptpw, cut, date, dc, dd, deallocvt, delgroup,
deluser, df, dhcprelay, diff, dirname, dmesg, dos2unix,
du, dumpkmap, dumpleases, echo, ed, egrep, eject, env,
envdir, envuidgid, expand, expr, false, fbset, fdflush,
fdformat, fdisk, fgrep, find, fold, free, freeramdisk,
fsck, fsck.minix, fuser, getopt, getty, grep, gunzip,
gzip, halt, hdparm, head, hexdump, hostid, hostname, hwclock,
id, ifconfig, ifdown, ifup, inetd, init, insmod, install,
ip, ipaddr, ipcalc, ipcrm, ipcs, iplink, iproute, iprule,
iptunnel, kbd_mode, kill, killall, killall5, klogd, last,
length, less, linux32, linux64, linuxrc, ln, loadfont,
loadkmap, logger, login, logname, logread, losetup, lpd,
lpq, lpr, ls, lsattr, lsmod, lzmacat, makedevs, md5sum,
mdev, mesg, microcom, mkdir, mkfifo, mkfs.minix, mknod,
mkswap, mktemp, modprobe, more, mount, mountpoint, mt,
mv, nameif, netstat, nice, nmeter, nohup, nslookup, od,
openvt, passwd, patch, pgrep, pidof, ping, pipe_progress,
pivot_root, pkill, poweroff, printenv, printf, ps, pscan,
pwd, raidautorun, rdate, readlink, readprofile, realpath,
reboot, renice, reset, resize, rm, rmdir, rmmod, route,
rpm, rpm2cpio, run-parts, runlevel, runsv, runsvdir, rx,
script, sed, sendmail, seq, setarch, setconsole, setkeycodes,
setlogcons, setsid, setuidgid, sh, sha1sum, sleep, softlimit,
sort, split, start-stop-daemon, stat, strings, stty, su,
sulogin, sum, sv, svlogd, swapoff, swapon, switch_root,
sync, sysctl, syslogd, tac, tail, tar, taskset, tee, telnetd,
test, time, top, touch, tr, true, tty, ttysize, udhcpc,
udhcpd, umount, uname, uncompress, unexpand, uniq, unix2dos,
unlzma, unzip, uptime, usleep, uudecode, uuencode, vi,
vlock, watch, watchdog, wc, wget, which, who, whoami,
xargs, yes, zcat
=== Sony CE Linux (internal distribution) 1.13.4 build ===
=== Sony CE Linux (internal distribution) 1.13.4 build ===
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         umount, uname, uniq, usleep, vconfig, wc, xargs, zcat
         umount, uname, uniq, usleep, vconfig, wc, xargs, zcat
== POSIX-2008/SUSv4 ==
The best standards are the kind that describe reality, rather than attempting to impose a new one.  (I.E. a good standard should document, not legislate.)
The kind of standards which describe existing reality tend to be approved by more than one standards body, such ANSI and ISO both approving C.  That's why the IEEE POSIX committee's 2008 standard, the Single Unix Specification version 4, and the Open Group Base Specification edition 7 are all the same standard from three sources.
The [http://opengroup.org/onlinepubs/9699919799/idx/utilities.html
"utilities" section] these standards is devoted to the unix command line, and are the best such standard for our purposes.  (BusyBox was implemented with regard to SUSv3, an earlier version of this standard.)
=== Problems with the standard ===
Unfortunately, these standards describe a subset of reality, lacking any mention of commands such as init, login, or mount required to actually boot a system. It provides ipcrm and ipcs, but not ipcmk, so you can use System V IPC resources but not create them.
These standards also contain a large number of commands that are inappropriate for toybox to implement in its 1.0 release.  (Perhaps some of these could be reintroduced in later releases, but not now.)
Starting with the full "utilities" list, we first remove generally obsolete commands (compess ed ex pr uncompress uccp uustat uux), commands for the pre-CVS "SCCS" source control system (admin delta get prs rmdel sact sccs unget val what), fortran support (asa fort77), and batch processing support (batch qalter qdel qhold qmove qmsg qrerun qrls qselect qsig qstat qsub).
Some commands are for a compiler toolchain (ar c99 cflow ctags cxref getcat iconv lex m4 make nm strings strip tsort yacc), which is outside of toybox's mandate and should be supplied externally.  (Again, some of these may be revisited later, but not for toybox 1.0.)
Some commands are part of a command shell, and cannot be implemented as separate executables (alias bg cd command fc fg getopts hash jobs kill read type ulimit umask unalias wait).  These may be revisited as part of a built-in toybox shell, but are not exported into $PATH via symlinks.  (If you fork a child process and have it "cd" then exit, you've accomplished nothing.)
A few other commands are judgement calls, providing command-line internationalization support (iconv locale localedef), System V inter-process communication (ipcrm ipcs), and cross-tty communication from the minicomputer days (talk mesg write).  The "pax" utility was supplanted by tar, "mailx" is a command line email client, and "lp" submits files for printing to... what exactly?  (cups?)  The standard defines crontab but not crond.
Removing all of that leaves the following commands, which toybox should implement:
  at awk basename bc cal cat chgrp chmod chown cksum cmp comm cp
  csplit cut date dd df diff dirname du echo env expand expr false file find
  fold fuser getconf grep head id join kill link ln logger logname ls man
  mkdir mkfifo more mv newgrp nice nl nohup od paste patch pathchk printf ps
  pwd renice rm rmdir sed sh sleep sort split stty tabs tail tee test time
  touch tput tr true tty uname unexpand uniq unlink uudecode uuencode vi wc
  who xargs zcat
=== Prioritization ===
=== Prioritization ===
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Rob wrote:
Rob wrote:
One nice thing about busybox/toybox/toolbox is you can install multiple
One nice thing about busybox/toolbox is you can install multiple
implementations side by side, and have what symlinks you create (or what
implementations side by side, and have what symlinks you create (or what
comes first in the $PATH) determine who is implementing what.
comes first in the $PATH) determine who is implementing what.

Revision as of 04:09, 23 February 2012

The Toybox material has moved to http://landley.net/toybox/roadmap.html

Beastiebox currently implements

Here’s a link to the Beastiebox project: http://beastiebox.sourceforge.net/ which has been proven to be capable to replace busybox, in general. It mostly consists of BSD sources and contains, according to the homepage:

 [ cat chmod cp date df disklabel dmesg ex fdisk fsck fsck_ffs
 getty halt hostname ifconfig init kill less ln login ls mksh more
 mount mount_ffs mv pfctl ping poweroff ps reboot rm route sed sh
 stty sysctl tar test traceroute umount vi wiconfig

On the TODO side, the Linux specific commands would need to be implemented or taken from one of the others (Toybox, Android Toolbox, etc).

It does contain a complete shell (mksh, MirBSD Korn Shell) under a BSD-ish licence, which can be used as /bin/sh (e.g. on Debian) and is the default /system/bin/sh on Android ICS and later, even. This is not much bigger than the sh included with Busybox, Beastiebox (can be disabled in favour of mksh) and others, but has functions such as command line editing, UTF-8 support, Tab completion, Korn Shell scripting features ([[, arrays, etc). and is actively developed on its own.

Sony CE Linux (internal distribution) 1.13.4 build

This is from a version of busybox used in lots of Sony products: Currently defined functions:

        [, [[, ash, basename, bunzip2, bzcat, cat, chgrp, chmod, chown,
        chroot, cmp, cp, cpio, cut, date, dd, dirname, dmesg, echo, egrep,
        env, expr, false, fgrep, freeramdisk, ftpget, ftpput, getty, grep,
        gunzip, gzip, halt, ifconfig, insmod, kill, killall, klogd, ln,
        logger, login, ls, lsmod, md5sum, mkdir, mkfifo, mknod, mktemp,
        modprobe, mount, mv, pidof, ping, ping6, pivot_root, poweroff,
        pwd, readlink, reboot, rm, rmdir, rmmod, route, sed, sfdisk, sh,
        sha1sum, sleep, sort, stty, swapoff, swapon, switch_root, sync,
        syslogd, tail, tar, taskset, telnet, telnetd, test, touch, true,
        umount, uname, uniq, usleep, vconfig, wc, xargs, zcat


The following is Tim's prioritization of the above list, based on his own experience with embedded systems. I will divide the above list into 3 groups: must-have, nice-to-have, not-that-important.


cat chgrp chmod chown cp date df
echo env expr false find grep head id kill ln
ls mkdir more mv nice ps pwd rm rmdir sh sleep
sort tail test touch true uname uniq wc xargs

(must have, not in the above list: chroot, dmesg, sync)


basename cut dd diff dirname du mkfifo printf sed tee time vi who zcat


at awk bc cal cksum cmp comm csplit expand file
fold fuser getconf link logger logname man newgrp nl
nohup od paste patch pathchk renice split stty tabs
tput tr tty unexpand unlink uudecode uuencode

Must-have unimplemented: The following list has Tim's must-have commands, which are currently (as of Jan, 2012) not implemented in toybox:

chgrp chmod chown date dd
expr find grep head id kill ln
ls mkdir more mv nice ps rm
tail test touch uniq xargs

prioritized, must-have, unimplemented list

Prioritized top 13:

1. ls
2. mkdir
3. rm
4. ln
5. mv
6. ps
7. kill
8. chmod
9. chown
10. date
11. grep
12. find
13. xargs

Second prioritized group:

chgrp id nice expr head tail test touch uniq dd more

IMHO - ls needs to support -ladR at first

toolbox complement

If we omit toolbox supported commands from the must-have, unimplemented list, we get:

chgrp expr false find grep head more
nice tail test touch true uname xargs

I would add tab completion and globbing for toysh to the list.

This would be for a toolbox complement.

Random Notes

Can implement incrementally

Rob wrote:

One nice thing about busybox/toolbox is you can install multiple implementations side by side, and have what symlinks you create (or what comes first in the $PATH) determine who is implementing what.

This allows gradual transitions. Each release, we replace a couple more commands from the old one, until the old one finally isn't being used for anything anymore and we can uninstall it...