BusyBox - The Swiss Army Knife of Embedded Linux
This documentation is free software; you can redistribute
it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied
warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
MA 02111-1307 USA
For more details see the file COPYING in the source
distribution of Linux.
Introduction
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 embedded 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).
How to use BusyBox
Syntax
BusyBox <function> [arguments...] # or
<function> [arguments...] # if symlinked
Invoking BusyBox
When you create a link to BusyBox for the function you wish to use, when
BusyBox is called using that link it will behave as if the command itself
has been invoked.
For example, entering
ln -s ./BusyBox ls
./ls
will cause BusyBox to behave as 'ls' (if the 'ls' command has been compiled
into BusyBox).
You can also invoke BusyBox by issuing the command as an argument on the
command line. For example, entering
./BusyBox ls
will also cause BusyBox to behave as 'ls'.
Common options
Most BusyBox commands support the --help option to provide
a terse runtime description of their behavior.
BusyBox Commands
Available BusyBox Commands
Currently defined functions include:
ar, basename, cat, chgrp, chmod, chown, chroot, chvt, clear,
cp, cut, date, dc, dd, deallocvt, df, dirname, dmesg, dpkg-deb,
du, dumpkmap, dutmp, echo, false, fbset, fdflush, find, free,
freeramdisk, fsck.minix, grep, gunzip, gzip, halt, head,
hostid, hostname, id, init, insmod, kill, killall, length, ln,
loadacm, loadfont, loadkmap, logger, logname, ls, lsmod,
makedevs, mkdir, mkfifo, mkfs.minix, mknod, mkswap, mktemp,
more, mount, mt, mv, nc, nslookup, ping, poweroff, printf, ps,
pwd, reboot, renice, reset, rm, rmdir, rmmod, run-parts, sed, setkeycodes, sh, sleep,
sort, swapoff, swapon, sync, syslogd, tail, tar, tee, telnet,
test, touch, tr, true, tty, umount, uname, uniq, update,
uptime, usleep, uudecode, uuencode, wc, which, whoami, yes,
zcat, [
ar
Usage: ar [OPTION] archive [FILENAME]...
Extract or list files from an ar archive.
Options:
o Preserve original dates
p Extract to stdout
t List
x Extract
v Verbosely list files processed
basename
Usage: basename FILE [SUFFIX]
Strip directory path and suffixes from FILE. If specified, also removes
any trailing SUFFIX.
Example:
$ basename /usr/local/bin/foo
foo
$ basename /usr/local/bin/
bin
$ basename /foo/bar.txt .txt
bar
cat
Usage: cat [FILE]...
Concatenate FILE(s) and prints them to the standard
output.
Example:
$ cat /proc/uptime
110716.72 17.67
chgrp
Usage: chgrp [OPTION]... GROUP FILE...
Change the group membership of each FILE to GROUP.
Options:
-R Change files and directories recursively
Example:
$ ls -l /tmp/foo
-r--r--r-- 1 andersen andersen 0 Apr 12 18:25 /tmp/foo
$ chgrp root /tmp/foo
$ ls -l /tmp/foo
-r--r--r-- 1 andersen root 0 Apr 12 18:25 /tmp/foo
chmod
Usage: chmod [-R] MODE[,MODE]... FILE...
Change file access permissions for the specified
FILE(s) (or directories). Each MODE is defined by
combining the letters for WHO has access to the file, an OPERATOR for
selecting how the permissions should be changed, and a PERMISSION for
FILE(s) (or directories).
WHO may be chosen from
u User who owns the file
g Users in the file's Group
o Other users not in the file's group
a All users
OPERATOR may be chosen from
+ Add a permission
- Remove a permission
= Assign a permission
PERMISSION may be chosen from
r Read
w Write
x Execute (or access for directories)
s Set user (or group) ID bit
t Sticky bit (for directories prevents removing files by non-owners)
Alternately, permissions can be set numerically where the first three
numbers are calculated by adding the octal values, such as
4 Read
2 Write
1 Execute
An optional fourth digit can also be used to specify
4 Set user ID
2 Set group ID
1 Sticky bit
Options:
-R Change files and directories recursively.
Example:
$ ls -l /tmp/foo
-rw-rw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo
$ chmod u+x /tmp/foo
$ ls -l /tmp/foo
-rwxrw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo*
$ chmod 444 /tmp/foo
$ ls -l /tmp/foo
-r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo
chown
Usage: chown [OPTION]... OWNER[<.|:>[GROUP] FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP.
Options:
-R Change files and directories recursively
Example:
$ ls -l /tmp/foo
-r--r--r-- 1 andersen andersen 0 Apr 12 18:25 /tmp/foo
$ chown root /tmp/foo
$ ls -l /tmp/foo
-r--r--r-- 1 root andersen 0 Apr 12 18:25 /tmp/foo
$ chown root.root /tmp/foo
ls -l /tmp/foo
-r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo
chroot
Usage: chroot NEWROOT [COMMAND...]
Run COMMAND with root directory set to NEWROOT.
Example:
$ ls -l /bin/ls
lrwxrwxrwx 1 root root 12 Apr 13 00:46 /bin/ls -> /BusyBox
$ mount /dev/hdc1 /mnt -t minix
$ chroot /mnt
$ ls -l /bin/ls
-rwxr-xr-x 1 root root 40816 Feb 5 07:45 /bin/ls*
chvt
Usage: chvt N
Change the foreground virtual terminal to /dev/ttyN
clear
Usage: clear
Clear the screen.
cp
Usage: cp [OPTION]... SOURCE DEST
or: cp [OPTION]... SOURCE... DIRECTORY
Copy SOURCE to DEST, or multiple SOURCE(s) to
DIRECTORY.
Options:
-a Same as -dpR
-d Preserve links
-p Preserve file attributes if possible
-R Copy directories recursively
cut
Usage: cut [OPTION]... [FILE]...
Print selected fields from each input FILE to standard output.
Options:
-b LIST Output only bytes from LIST
-c LIST Output only characters from LIST
-d CHAR Use CHAR instead of tab as the field delimiter
-s Output only the lines containing delimiter
-f N Print only these fields
-n Ignored
Example:
$ echo "Hello world" | cut -f 1 -d ' '
Hello
$ echo "Hello world" | cut -f 2 -d ' '
world
date
Usage: date [OPTION]... [+FORMAT]
or: date [OPTION] [MMDDhhmm[[CC]YY][.ss]]
Display the current time in the given FORMAT, or set the system date.
Options:
-R Output RFC-822 compliant date string
-s Set time described by STRING
-u Print or set Coordinated Universal Time
Example:
$ date
Wed Apr 12 18:52:41 MDT 2000
dc
Usage: dc [EXPRESSION]
This is a Tiny RPN calculator that understands the
following operations: +, -, /, *, and, or, not, eor. If
no arguments are given, dc will process input from
stdin.
The behaviour of BusyBox/dc deviates (just a little ;-)
from GNU/dc, but this will be remedied in the future.
Example:
$ dc 2 2 +
4
$ dc 8 8 \* 2 2 + /
16
$ dc 0 1 and
0
$ dc 0 1 or
1
$ echo 72 9 div 8 mul | dc
64
dd
Usage: dd [OPTION]...
Copy a file, converting and formatting according to
options.
Options:
if=FILE Read from FILE instead of stdin
of=FILE Write to FILE instead of stdout
bs=N Read and write N bytes at a time
count=N Copy only N input blocks
skip=N Skip N input blocks
seek=N Skip N output blocks
Numbers may be suffixed by w (x2), k (x1024), b (x512),
or M (x1024^2).
Example:
$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4
4+0 records in
4+0 records out
deallocvt
Usage: deallocvt N
Deallocate unused virtual terminal /dev/ttyN.
df
Usage: df [FILE]...
Print the filesystem space used and space available.
Example:
$ df
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/sda3 8690864 8553540 137324 98% /
/dev/sda1 64216 36364 27852 57% /boot
$ df /dev/sda3
Filesystem 1k-blocks Used Available Use% Mounted on
/dev/sda3 8690864 8553540 137324 98% /
dirname
Usage: dirname NAME
Strip non-directory suffix from NAME.
Example:
$ dirname /tmp/foo
/tmp
$ dirname /tmp/foo/
/tmp
dmesg
Usage: dmesg [OPTION]...
Print or control the kernel ring buffer.
Options:
-c Clear the ring buffer after printing
-n LEVEL Set the console logging level to LEVEL
-s BUFSIZE Query ring buffer using a buffer of BUFSIZE
dos2unix
Usage: dos2unix < dosfile > unixfile
Converts a text file from dos format to unix format.
dpkg-deb
Usage: dpkg-deb [OPTION] archive [directory]
Debian package archive (.deb) manipulation tool
Options:
-c List the contents of the filesystem tree archive portion of the package
-e Extracts the control information files from a package archive into the specified directory.
If no directory is specified then a subdirectory DEBIAN in the current directory is used.
-x Silently extracts the filesystem tree from a package archive into the specified directory.
-X Extracts the filesystem tree from a package archive into the specified directory, listing the files as it goes.
If required the specified directory (but not its parents) will be created.
Example:
dpkg-deb -e ./busybox_0.48-1_i386.deb
dpkg-deb -x ./busybox_0.48-1_i386.deb ./unpack_dir
du
Usage: du [OPTION]... [FILE]...
Summarize the disk space used for each FILE or current
directory. Disk space printed in units of 1k (i.e.,
1024 bytes).
Options:
-l Count sizes many times if hard linked
-s Display only a total for each argument
Example:
$ du
16 ./CVS
12 ./kernel-patches/CVS
80 ./kernel-patches
12 ./tests/CVS
36 ./tests
12 ./scripts/CVS
16 ./scripts
12 ./docs/CVS
104 ./docs
2417 .
dumpkmap
Usage: dumpkmap
Prints out a binary keyboard translation table to standard output.
Example:
$ dumpkmap < keymap
dutmp
Usage: dutmp [FILE]
Dump utmp file format (pipe delimited) from FILE or
stdin to stdout.
Example:
$ dutmp /var/run/utmp
8|7||si|||0|0|0|955637625|760097|0
2|0|~|~~|reboot||0|0|0|955637625|782235|0
1|20020|~|~~|runlevel||0|0|0|955637625|800089|0
8|125||l4|||0|0|0|955637629|998367|0
6|245|tty1|1|LOGIN||0|0|0|955637630|998974|0
6|246|tty2|2|LOGIN||0|0|0|955637630|999498|0
7|336|pts/0|vt00andersen|andersen|:0.0|0|0|0|955637763|0|0
echo
Usage: echo [OPTION]... [ARG]...
Print ARGs to stdout.
Options:
-n Suppress trailing newline
-e Enable interpretation of escaped characters
-E Disable interpretation of escaped characters
Example:
$ echo "Erik is cool"
Erik is cool
$ echo -e "Erik\nis\ncool"
Erik
is
cool
$ echo "Erik\nis\ncool"
Erik\nis\ncool
expr
Usage: expr EXPRESSION
Prints the value of EXPRESSION to standard output.
EXPRESSION may be:
ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2
ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0
ARG1 < ARG2 ARG1 is less than ARG2
ARG1 <= ARG2 ARG1 is less than or equal to ARG2
ARG1 = ARG2 ARG1 is equal to ARG2
ARG1 != ARG2 ARG1 is unequal to ARG2
ARG1 >= ARG2 ARG1 is greater than or equal to ARG2
ARG1 > ARG2 ARG1 is greater than ARG2
ARG1 + ARG2 arithmetic sum of ARG1 and ARG2
ARG1 - ARG2 arithmetic difference of ARG1 and ARG2
ARG1 * ARG2 arithmetic product of ARG1 and ARG2
ARG1 / ARG2 arithmetic quotient of ARG1 divided by ARG2
ARG1 % ARG2 arithmetic remainder of ARG1 divided by ARG2
STRING : REGEXP anchored pattern match of REGEXP in STRING
match STRING REGEXP same as STRING : REGEXP
substr STRING POS LENGTH substring of STRING, POS counted from 1
index STRING CHARS index in STRING where any CHARS is found, or 0
length STRING length of STRING
quote TOKEN interpret TOKEN as a string, even if it is a
keyword like `match' or an operator like `/'
( EXPRESSION ) value of EXPRESSION
Beware that many operators need to be escaped or quoted for shells.
Comparisons are arithmetic if both ARGs are numbers, else
lexicographical. Pattern matches return the string matched between
\( and \) or null; if \( and \) are not used, they return the number
of characters matched or 0.
false
Usage: false
Return an exit code of FALSE (1).
Example:
$ false
$ echo $?
1
fbset
Usage: fbset [OPTION]... [MODE]
Show and modify frame buffer device settings.
Options:
-h Display option summary
-fb DEVICE Operate on DEVICE
-db FILE Use FILE for mode database
-g XRES YRES VXRES VYRES DEPTH Set all geometry parameters
-t PIXCLOCK LEFT RIGHT UPPER LOWER HSLEN VSLEN Set all timing parameters
-xres RES Set visible horizontal resolution
-yres RES Set visible vertical resolution
Example:
$ fbset
mode "1024x768-76"
# D: 78.653 MHz, H: 59.949 kHz, V: 75.694 Hz
geometry 1024 768 1024 768 16
timings 12714 128 32 16 4 128 4
accel false
rgba 5/11,6/5,5/0,0/0
endmode
fdflush
Usage: fdflush DEVICE
Force floppy disk drive to detect disk change on DEVICE.
find
Usage: find [PATH]... [EXPRESSION]
Search for files in a directory hierarchy. The default
PATH is the current directory; default EXPRESSION is
'-print'.
EXPRESSION may consist of:
-follow Dereference symbolic links
-name PATTERN File name (leading directories removed) matches PATTERN
-type X Filetype matches X (where X is one of: f,d,l,b,c,...)
-perm PERMS Permissions match any of (+NNN); all of (-NNN); or exactly (NNN)
-mtime TIME Modified time is greater than (+N); less than (-N); or exactly (N) days
Example:
$ find / -name /etc/passwd
/etc/passwd
free
Usage: free
Displays the amount of free and used system memory.
Example:
$ free
total used free shared buffers
Mem: 257628 248724 8904 59644 93124
Swap: 128516 8404 120112
Total: 386144 257128 129016
freeramdisk
Usage: freeramdisk DEVICE
Free all memory used by the ramdisk DEVICE.
Example:
$ freeramdisk /dev/ram2
fsck.minix
Usage: fsck.minix [OPTION]... DEVICE
Perform a consistency check on the MINIX filesystem on
DEVICE.
Options:
-l List all filenames
-r Perform interactive repairs
-a Perform automatic repairs
-v Verbose
-s Output super-block information
-m Activate MINIX-like "mode not cleared" warnings
-f Force file system check.
getopt
Usage: getopt [OPTIONS]...
Parse command options
-a, --alternative Allow long options starting with single -\n"
-l, --longoptions=longopts Long options to be recognized\n"
-n, --name=progname The name under which errors are reported\n"
-o, --options=optstring Short options to be recognized\n"
-q, --quiet Disable error reporting by getopt(3)\n"
-Q, --quiet-output No normal output\n"
-s, --shell=shell Set shell quoting conventions\n"
-T, --test Test for getopt(1) version\n"
-u, --unqote Do not quote the output\n"
Example:
$ cat getopt.test
#!/bin/sh
GETOPT=`getopt -o ab:c:: --long a-long,b-long:,c-long:: \
-n 'example.busybox' -- "$@"`
if [ $? != 0 ] ; then exit 1 ; fi
eval set -- "$GETOPT"
while true ; do
case $1 in
-a|--a-long) echo "Option a" ; shift ;;
-b|--b-long) echo "Option b, argument \`$2'" ; shift 2 ;;
-c|--c-long)
case "$2" in
"") echo "Option c, no argument"; shift 2 ;;
*) echo "Option c, argument \`$2'" ; shift 2 ;;
esac ;;
--) shift ; break ;;
*) echo "Internal error!" ; exit 1 ;;
esac
done
grep
Usage: grep [OPTIONS]... PATTERN [FILE]...
Search for PATTERN in each FILE or stdin.
Options:
-h Suppress the prefixing filename on output
-i Ignore case distinctions
-n Print line number with output lines
-q Be quiet. Returns 0 if result was found, 1 otherwise
-v Select non-matching lines
This version of grep matches full regular expressions.
Example:
$ grep root /etc/passwd
root:x:0:0:root:/root:/bin/bash
$ grep ^[rR]oo. /etc/passwd
root:x:0:0:root:/root:/bin/bash
gunzip
Usage: gunzip [OPTION]... FILE
Uncompress FILE (or stdin if FILE is '-').
Options:
-c Write output to standard output
-t Test compressed file integrity
Example:
$ ls -la /tmp/BusyBox*
-rw-rw-r-- 1 andersen andersen 557009 Apr 11 10:55 /tmp/BusyBox-0.43.tar.gz
$ gunzip /tmp/BusyBox-0.43.tar.gz
$ ls -la /tmp/BusyBox*
-rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/BusyBox-0.43.tar
gzip
Usage: gzip [OPTION]... FILE
Compress FILE (or stdin if FILE is '-') with maximum
compression to FILE.gz (or stdout if FILE is '-').
Options:
-c Write output to standard output
-d decompress
Example:
$ ls -la /tmp/BusyBox*
-rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/BusyBox-0.43.tar
$ gzip /tmp/BusyBox-0.43.tar
$ ls -la /tmp/BusyBox*
-rw-rw-r-- 1 andersen andersen 554058 Apr 14 17:49 /tmp/BusyBox-0.43.tar.gz
halt
Usage: halt
Halt the system.
head
Usage: head [OPTION] FILE...
Print first 10 lines of each FILE to standard output.
With more than one FILE, precede each with a header
giving the file name. With no FILE, or when FILE is -,
read standard input.
Options:
-n NUM Print first NUM lines instead of first 10
Example:
$ head -n 2 /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
hostid
Usage: hostid
Prints out a unique 32-bit identifier for the current
machine. The 32-bit identifier is intended to be unique
among all UNIX systems in existence.
hostname
Usage: hostname [OPTION]... [HOSTNAME|-F FILE]
Get or set the hostname or DNS domain name. If a
hostname is given (or a file with the -F parameter), the
host name will be set.
Options:
-s Short
-i Addresses for the hostname
-d DNS domain name
-F, --file FILE Use the contents of FILE to specify the hostname
Example:
$ hostname
slag
id
Usage: id [OPTION]... [USERNAME]
Print information for USERNAME or the current user.
Options:
-g Print only the group ID
-u Print only the user ID
-n print a name instead of a number (with for -ug)
-r Print the real user ID instead of the effective ID (with -ug)
Example:
$ id
uid=1000(andersen) gid=1000(andersen)
init
Usage: init
Init is the parent of all processes.
This version of init is designed to be run only by the
kernel.
BusyBox init doesn't support multiple runlevels. The
runlevels field of the /etc/inittab file is completely
ignored by BusyBox init. If you want runlevels, use
sysvinit.
BusyBox init works just fine without an inittab. If no
inittab is found, it has the following default behavior:
::sysinit:/etc/init.d/rcS
::askfirst:/bin/sh
If it detects that /dev/console is _not_ a serial
console, it will also run:
tty2::askfirst:/bin/sh
If you choose to use an /etc/inittab file, the inittab
entry format is as follows:
<id>:<runlevels>:<action>:<process>
id
WARNING: This field has a non-traditional meaning for BusyBox init!
The id field is used by BusyBox init to specify the controlling tty
for the specified process to run on. The contents of this field
are appended to "/dev/" and used as-is. There is no need for this
field to be unique, although if it isn't you may have strange
results. If this field is left blank, the controlling tty is set
to the console. Also note that if BusyBox detects that a serial
console is in use, then only entries whose controlling tty is
either the serial console or /dev/null will be run. BusyBox init
does nothing with utmp. We don't need no stinkin' utmp.
runlevels
The runlevels field is completely ignored.
action
Valid actions include: sysinit, respawn, askfirst, wait,
once, and ctrlaltdel.
The available actions can be classified into two groups: actions
that are run only once, and actions that are re-run when the specified
process exits.
Run only-once actions:
'sysinit' is the first item run on boot. init waits until all
sysinit actions are completed before continuing. Following the
completion of all sysinit actions, all 'wait' actions are run.
'wait' actions, like 'sysinit' actions, cause init to wait until
the specified task completes. 'once' actions are asyncronous,
therefore, init does not wait for them to complete. 'ctrlaltdel'
actions are run immediately before init causes the system to reboot
(unmounting filesystems with a 'ctrlaltdel' action is a very good
idea).
Run repeatedly actions:
'respawn' actions are run after the 'once' actions. When a process
started with a 'respawn' action exits, init automatically restarts
it. Unlike sysvinit, BusyBox init does not stop processes from
respawning out of control. The 'askfirst' actions acts just like
respawn, except that before running the specified process it
displays the line "Please press Enter to activate this console."
and then waits for the user to press enter before starting the
specified process.
Unrecognized actions (like initdefault) will cause init to emit an
error message, and then go along with its business. All actions are
run in the reverse order from how they appear in /etc/inittab.
process
Specifies the process to be executed and its
command line.
Example /etc/inittab file
# This is run first except when booting in single-user mode.
#
::sysinit:/etc/init.d/rcS
# /bin/sh invocations on selected ttys
#
# Start an "askfirst" shell on the console (whatever that may be)
::askfirst:-/bin/sh
# Start an "askfirst" shell on /dev/tty2-4
tty2::askfirst:-/bin/sh
tty2::askfirst:-/bin/sh
tty2::askfirst:-/bin/sh
# /sbin/getty invocations for selected ttys
#
tty4::respawn:/sbin/getty 38400 tty5
tty5::respawn:/sbin/getty 38400 tty6
# Example of how to put a getty on a serial line (for a terminal)
#
#::respawn:/sbin/getty -L ttyS0 9600 vt100
#::respawn:/sbin/getty -L ttyS1 9600 vt100
#
# Example how to put a getty on a modem line.
#::respawn:/sbin/getty 57600 ttyS2
# Stuff to do before rebooting
::ctrlaltdel:/bin/umount -a -r
::ctrlaltdel:/sbin/swapoff
insmod
Usage: insmod [OPTION]... MODULE [symbol=value]...
Load MODULE into the kernel.
Options:
-f Force module to load into the wrong kernel version.
-k Make module autoclean-able.
-v Verbose output
-x Do not export externs
-L Prevent simultaneous loads of the same module
kill
Usage: kill [OPTION] PID...
Send a signal (default is SIGTERM) to the specified
PID(s).
Options:
-l List all signal names and numbers
-SIG Send signal SIG
Example:
$ ps | grep apache
252 root root S [apache]
263 www-data www-data S [apache]
264 www-data www-data S [apache]
265 www-data www-data S [apache]
266 www-data www-data S [apache]
267 www-data www-data S [apache]
$ kill 252
killall
Usage: killall [OPTION] NAME...
Send a signal (default is SIGTERM) to the specified
NAME(s).
Options:
-l List all signal names and numbers
-SIG Send signal SIG
Example:
$ killall apache
length
Usage: length STRING
Print the length of STRING.
Example:
$ length "Hello"
5
ln
Usage: ln [OPTION]... TARGET FILE|DIRECTORY
Create a link named FILE or DIRECTORY to the specified
TARGET. You may use '--' to indicate that all following
arguments are non-options.
Options:
-s Make symbolic link instead of hard link
-f Remove existing destination file
Example:
$ ln -s BusyBox /tmp/ls
$ ls -l /tmp/ls
lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox*
loadacm
Usage: loadacm
Load an acm from stdin.
Example:
$ loadacm < /etc/i18n/acmname
loadfont
Usage: loadfont
Load a console font from stdin.
Example:
$ loadfont < /etc/i18n/fontname
loadkmap
Usage: loadkmap
Load a binary keyboard translation table from stdin.
Example:
$ loadkmap < /etc/i18n/lang-keymap
logger
Usage: logger [OPTION]... [MESSAGE]
Write MESSAGE to the system log. If MESSAGE is omitted, log
stdin.
Options:
-s Log to stderr as well as the system log
-t Log using the specified tag (defaults to user name)
-p Enter the message with the specified priority
This may be numerical or a ``facility.level'' pair
Example:
$ logger "hello"
logname
Usage: logname
Print the name of the current user.
Example:
$ logname
root
ls
Usage: ls [OPTION]... [FILE]...
Options:
-a Do not hide entries starting with .
-c With -l: show ctime (the time of last
modification of file status information)
-d List directory entries instead of contents
-e List both full date and full time
-l Use a long listing format
-n List numeric UIDs and GIDs instead of names
-p Append indicator (one of /=@|) to entries
-u With -l: show access time (the time of last
access of the file)
-x List entries by lines instead of by columns
-A Do not list implied . and ..
-C List entries by columns
-F Append indicator (one of */=@|) to entries
-L list entries pointed to by symbolic links
-R List subdirectories recursively
Example:
lsmod
Usage: lsmod
List currently loaded kernel modules.
makedevs
Usage: makedevsf NAME TYPE MAJOR MINOR FIRST LAST [s]
Create a range of block or character special files.
TYPE may be:
b Make a block (buffered) device
c or u Make a character (un-buffered) device
p Make a named pipe. MAJOR and MINOR are ignored for named pipes
FIRST specifies the number appended to NAME to create
the first device. LAST specifies the number of the last
item that should be created. If 's' is the last
argument, the base device is created as well.
Example:
$ makedevs /dev/ttyS c 4 66 2 63
[creates ttyS2-ttyS63]
$ makedevs /dev/hda b 3 0 0 8 s
[creates hda,hda1-hda8]
md5sum
Usage: md5sum [OPTION]... FILE...
Print or check MD5 checksums.
Options:
-b Read files in binary mode
-c Check MD5 sums against given list
-t Read files in text mode (default)
-g Read a string
The following two options are useful only when verifying
checksums:
-s Don't output anything, status code shows success
-w Warn about improperly formated MD5 checksum lines
Example:
$ md5sum busybox
6fd11e98b98a58f64ff3398d7b324003 busybox
$ md5sum -c
6fd11e98b98a58f64ff3398d7b324003 busybox
6fd11e98b98a58f64ff3398d7b324002 busybox
md5sum: MD5 check failed for 'busybox'
^D
mkdir
Usage: mkdir [OPTION]... DIRECTORY...
Create the DIRECTORY(s), if they do not already exist.
Options:
-m Set permission mode (as in chmod), not rwxrwxrwx - umask
-p No error if directory exists, make parent directories as needed
Example:
$ mkdir /tmp/foo
$ mkdir /tmp/foo
/tmp/foo: File exists
$ mkdir /tmp/foo/bar/baz
/tmp/foo/bar/baz: No such file or directory
$ mkdir -p /tmp/foo/bar/baz
mkfifo
Usage: mkfifo [OPTION] NAME
Create a named pipe (identical to 'mknod NAME p').
Options:
-m MODE Create the pipe using the specified mode (default a=rw)
mkfs.minix
Usage: mkfs.minix [OPTION]... NAME [BLOCKS]
Make a MINIX filesystem.
Options:
-c Check the device for bad blocks
-n [14|30] Specify the maximum length of filenames
-i Specify the number of inodes for the filesystem
-l FILENAME Read the bad blocks list from FILENAME
-v Make a Minix version 2 filesystem
mknod
Usage: mknod [OPTION]... NAME TYPE MAJOR MINOR
Create a special file (block, character, or pipe).
Options:
-m Create the special file using the specified mode (default a=rw)
TYPE may be:
b Make a block (buffered) device
c or u Make a character (un-buffered) device
p Make a named pipe. MAJOR and MINOR are ignored for named pipes
Example:
$ mknod /dev/fd0 b 2 0
$ mknod -m 644 /tmp/pipe p
mkswap
Usage: mkswap [OPTION]... DEVICE [BLOCKS]
Prepare a disk partition to be used as a swap partition.
Options:
-c Check for read-ability.
-v0 Make version 0 swap [max 128 Megs].
-v1 Make version 1 swap [big!] (default for kernels > 2.1.117).
BLOCKS Number of block to use (default is entire partition).
mktemp
Usage: mktemp TEMPLATE
Creates a temporary file with its name based on
TEMPLATE. TEMPLATE is any name with six `Xs' (i.e.,
/tmp/temp.XXXXXX).
Example:
$ mktemp /tmp/temp.XXXXXX
/tmp/temp.mWiLjM
$ ls -la /tmp/temp.mWiLjM
-rw------- 1 andersen andersen 0 Apr 25 17:10 /tmp/temp.mWiLjM
more
Usage: more [FILE]...
Page through text one screenful at a time.
Example:
$ dmesg | more
mount
Usage: mount [OPTION]...
or: mount [OPTION]... DEVICE DIRECTORY
Mount filesystems.
Options:
-a Mount all filesystems in /etc/fstab
-o One of the many filesystem options listed below
-r Mount the filesystem read-only
-t TYPE Specify the filesystem type
-w Mount the filesystem read-write
Options for use with the -o flag:
async/sync Writes are asynchronous / synchronous
atime/noatime Enable / disable updates to inode access times
dev/nodev Allow / disallow use of special device files
exec/noexec Allow / disallow use of executable files
loop Mount a file via loop device
suid/nosuid Allow / disallow set-user-id-root programs
remount Remount a currently mounted filesystem
ro/rw Mount filesystem read-only / read-write
There are even more flags that are filesystem specific.
You'll have to see the written documentation for those.
Example:
$ mount
/dev/hda3 on / type minix (rw)
proc on /proc type proc (rw)
devpts on /dev/pts type devpts (rw)
$ mount /dev/fd0 /mnt -t msdos -o ro
$ mount /tmp/diskimage /opt -t ext2 -o loop
mt
Usage: mt [OPTION] OPCODE VALUE
Control magnetic tape drive operation.
Options:
-f DEVICE Control DEVICE
mv
Usage: mv SOURCE DEST
or: mv SOURCE... DIRECTORY
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.
Example:
$ mv /tmp/foo /bin/bar
nc
Usage: nc HOST PORT
or: nc -p PORT -l
Open a pipe to HOST:PORT or listen for a connection on PORT.
Example:
$ nc foobar.somedomain.com 25
220 foobar ESMTP Exim 3.12 #1 Sat, 15 Apr 2000 00:03:02 -0600
help
214-Commands supported:
214- HELO EHLO MAIL RCPT DATA AUTH
214 NOOP QUIT RSET HELP
quit
221 foobar closing connection
nslookup
Usage: nslookup [HOST]
Query the nameserver for the IP address of the given
HOST.
Example:
$ nslookup localhost
Server: default
Address: default
Name: debian
Address: 127.0.0.1
ping
Usage: ping [OPTION]... HOST
Send ICMP ECHO_REQUEST packets to HOST.
Options:
-c COUNT Send only COUNT pings
-s SIZE Send SIZE data bytes in packets (default=56)
-q Quiet mode, only displays output at start and when finished
Example:
$ ping localhost
PING slag (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=20.1 ms
--- debian ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 20.1/20.1/20.1 ms
poweroff
Usage: poweroff
Shut down the system, and request that the kernel turn
off power upon halting.
printf
Usage: printf FORMAT [ARGUMENT]...
Format and print the given data in a manner similar to
the C printf command.
Example:
$ printf "Val=%d\n" 5
Val=5
ps
Usage: ps
Report process status. This version of ps accepts no
options.
Options:
Example:
$ ps
PID Uid Gid State Command
1 root root S init
2 root root S [kflushd]
3 root root S [kupdate]
4 root root S [kpiod]
5 root root S [kswapd]
742 andersen andersen S [bash]
743 andersen andersen S -bash
745 root root S [getty]
2990 andersen andersen R ps
pwd
Usage: pwd
Print the full filename of the current working
directory.
Example:
$ pwd
/root
rdate
Usage: rdate [OPTION] HOST
Get and possibly set the system date and time from a remote HOST.
Options:
-s Set the system date and time (default).
-p Print the date and time.
reboot
Usage: reboot
Reboot the system.
renice
Usage: renice priority pid [pid ...]
Changes priority of running processes. Allowed priorities range
from 20 (the process runs only when nothing else is running) to 0
(default priority) to -20 (almost nothing else ever gets to run).
reset
Usage: reset
Resets the screen.
rm
Usage: rm [OPTION]... FILE...
Remove (unlink) the FILE(s). You may use '--' to
indicate that all following arguments are non-options.
Options:
-i Always prompt before removing each destinations
-f Remove existing destinations, never prompt
-r or -R Remove the contents of directories recursively
Example:
$ rm -rf /tmp/foo
rmdir
Usage: rmdir DIRECTORY...
Remove DIRECTORY(s) if they are empty.
Example:
$ rmdir /tmp/foo
rmmod
Usage: rmmod [OPTION]... [MODULE]...
Unload MODULE(s) from the kernel.
Options:
-a Try to remove all unused kernel modules
Example:
$ rmmod tulip
run-parts
Usage: run-parts [-t] [-a ARG] [-u MASK] DIRECTORY
Run a bunch of scripts in a directory.
Options:
-t Test only. It only print the file to be executed,
without execute them.
-a ARG Pass ARG as an a argument to the programs executed.
-u MASK Set the umask to MASK before executing the programs.
sed
Usage: sed [OPTION]... SCRIPT [FILE]...
Allowed sed scripts come in the following form:
ADDR [!] COMMAND
ADDR can be:
NUMBER Match specified line number
$ Match last line
/REGEXP/ Match specified regexp
! inverts the meaning of the match
COMMAND can be:
s/regexp/replacement/[igp]
which attempt to match regexp against the pattern space
and if successful replaces the matched portion with replacement.
aTEXT
which appends TEXT after the pattern space
This version of sed matches full regular expressions.
Options:
-e Add the script to the commands to be executed
-n Suppress automatic printing of pattern space
Example:
$ echo "foo" | sed -e 's/f[a-zA-Z]o/bar/g'
bar
setkeycodes
Usage: setkeycodes SCANCODE KEYCODE ...
Set entries into the kernel's scancode-to-keycode map,
allowing unusual keyboards to generate usable keycodes.
SCANCODE may be either xx or e0xx (hexadecimal), and
KEYCODE is given in decimal.
Example:
$ setkeycodes e030 127
sh
Usage: sh
lash -- the BusyBox LAme SHell (command interpreter)
This command does not yet have proper documentation.
Use lash just as you would use any other shell. It
properly handles pipes, redirects, job control, can be
used as the shell for scripts (#!/bin/sh), and has a
sufficient set of builtins to do what is needed. It does
not (yet) support Bourne Shell syntax. If you need
things like ``if-then-else'', ``while'', and such, use
ash or bash. If you just need a very simple and
extremely small shell, this will do the job.
sleep
Usage: sleep N
Pause for N seconds.
Example:
$ sleep 2
[2 second delay results]
sort
Usage: sort [OPTION]... [FILE]...
Sort lines of text in FILE(s).
Options:
-n Compare numerically
-r Reverse after sorting
Example:
$ echo -e "e\nf\nb\nd\nc\na" | sort
a
b
c
d
e
f
swapoff
Usage: swapoff [OPTION] [DEVICE]
Stop swapping virtual memory pages on DEVICE.
Options:
-a Stop swapping on all swap devices
swapon
Usage: swapon [OPTION] [DEVICE]
Start swapping virtual memory pages on the given device.
Options:
-a Start swapping on all swap devices
sync
Usage: sync
Write all buffered filesystem blocks to disk.
syslogd
Usage: syslogd [OPTION]...
Linux system and kernel (provides klogd) logging
utility. Note that this version of syslogd/klogd ignores
/etc/syslog.conf.
Options:
-m NUM Interval between MARK lines (default=20min, 0=off)
-n Run as a foreground process
-K Do not start up the klogd process
-O FILE Use an alternate log file (default=/var/log/messages)
-R HOST[:PORT] Log remotely to IP or hostname on PORT (default PORT=514/UDP)
-L Log locally as well as network logging (default is network only)
Example:
$ syslogd -R masterlog:514
$ syslogd -R 192.168.1.1:601
tail
Usage: tail [OPTION] [FILE]...
Print last 10 lines of each FILE to standard output.
With more than one FILE, precede each with a header
giving the file name. With no FILE, or when FILE is -,
read stdin.
Options:
-n NUM Print last NUM lines instead of last 10
-f Output data as the file grows. This version
of 'tail -f' supports only one file at a time.
Example:
$ tail -n 1 /etc/resolv.conf
nameserver 10.0.0.1
tar
Usage: tar [MODE] [OPTION] [FILE]...
MODE may be chosen from
c Create
x Extract
t List
Options:
f FILE Use FILE for tarfile (or stdin if '-')
O Extract to stdout
exclude FILE File to exclude
v List files processed
Example:
$ zcat /tmp/tarball.tar.gz | tar -xf -
$ tar -cf /tmp/tarball.tar /usr/local
tee
Usage: tee [OPTION]... [FILE]...
Copy stdin to FILE(s), and also to stdout.
Options:
-a Append to the given FILEs, do not overwrite
Example:
$ echo "Hello" | tee /tmp/foo
Hello
$ cat /tmp/foo
Hello
telnet
Usage: telnet HOST [PORT]
Establish interactive communication with another
computer over a network using the TELNET protocol.
test, [
Usage: test EXPRESSION
or: [ EXPRESSION ]
Check file types and compare values returning an exit
code determined by the value of EXPRESSION.
Example:
$ test 1 -eq 2
$ echo $?
1
$ test 1 -eq 1
$ echo $?
0
$ [ -d /etc ]
$ echo $?
0
$ [ -d /junk ]
$ echo $?
1
touch
Usage: touch [OPTION]... FILE...
Update the last-modified date on (or create) FILE(s).
Options:
-c Do not create files
Example:
$ ls -l /tmp/foo
/bin/ls: /tmp/foo: No such file or directory
$ touch /tmp/foo
$ ls -l /tmp/foo
-rw-rw-r-- 1 andersen andersen 0 Apr 15 01:11 /tmp/foo
tr
Usage: tr [OPTION]... STRING1 [STRING2]
Translate, squeeze, and/or delete characters from stdin,
writing to stdout.
Options:
-c Take complement of STRING1
-d Delete input characters coded STRING1
-s Squeeze multiple output characters of STRING2 into one character
Example:
$ echo "gdkkn vnqkc" | tr [a-y] [b-z]
hello world
true
Usage: true
Return an exit code of TRUE (1).
Example:
$ true
$ echo $?
0
tty
Usage: tty
Print the file name of the terminal connected to stdin.
Options:
-s Print nothing, only return an exit status
Example:
$ tty
/dev/tty2
umount
Usage: umount [OPTION]... DEVICE|DIRECTORY
Options:
-a Unmount all file systems
-r Try to remount devices as read-only if mount is busy
-f Force filesystem umount (i.e., unreachable NFS server)
-l Do not free loop device (if a loop device has been used)
Example:
$ umount /dev/hdc1
uname
Usage: uname [OPTION]...
Print certain system information. With no OPTION, same
as -s.
Options:
-a Print all information
-m Print the machine (hardware) type
-n Print the machine's network node hostname
-r Print the operating system release
-s Print the operating system name
-p Print the host processor type
-v Print the operating system version
Example:
$ uname -a
Linux debian 2.2.15pre13 #5 Tue Mar 14 16:03:50 MST 2000 i686 unknown
uniq
Usage: uniq [INPUT [OUTPUT]]
Discard all but one of successive identical lines from
INPUT (or stdin), writing to OUTPUT (or stdout).
Options:
-c prefix lines by the number of occurrences
-d only print duplicate lines
-u only print unique lines
Example:
$ echo -e "a\na\nb\nc\nc\na" | sort | uniq
a
b
c
unix2dos
Usage: unix2dos < unixfile > dosfile
Converts a text file from unix format to dos format.
unrpm
Usage: unrpm < package.rpm | gzip -d | cpio -idmuv
Extracts an rpm archive.
update
Usage: update [OPTION]...
Periodically flush filesystem buffers.
Options:
-S Force use of sync(2) instead of flushing
-s SECS Call sync this often (default 30)
-f SECS Flush some buffers this often (default 5)
uptime
Usage: uptime
Display how long the system has been running since boot.
Example:
$ uptime
1:55pm up 2:30, load average: 0.09, 0.04, 0.00
usleep
Usage: usleep N
Pause for N microseconds.
Example:
$ usleep 1000000
[pauses for 1 second]
uudecode
Usage: uudecode [OPTION] [FILE]
Uudecode a uuencoded file.
Options:
-o FILE Direct output to FILE
Example:
$ uudecode -o busybox busybox.uu
$ ls -l busybox
-rwxr-xr-x 1 ams ams 245264 Jun 7 21:35 busybox
uuencode
Usage: uuencode [OPTION] [INFILE] OUTFILE
Uuencode a file.
Options:
-m Use base64 encoding as of RFC1521
Example:
$ uuencode busybox busybox
begin 755 busybox
M?T5,1@$!`0````````````(``P`!````L+@$"#0```!0N@,``````#0`(``&
.....
$ uudecode busybox busybox > busybox.uu
$
watchdog
Usage: watchdog device
Periodically writes to watchdog device B.
wc
Usage: wc [OPTION]... [FILE]...
Print line, word, and byte counts for each FILE, and a
total line if more than one FILE is specified. With no
FILE, read stdin.
Options:
-c Print the byte counts
-l Print the newline counts
-L Print the length of the longest line
-w Print the word counts
Example:
$ wc /etc/passwd
31 46 1365 /etc/passwd
which
Usage: which [COMMAND]...
Locate COMMAND(s).
Example:
$ which login
/bin/login
whoami
Usage: whoami
Print the user name associated with the current
effective user id.
Example:
$ whoami
andersen
xargs
Usage: xargs [OPTIONS] [COMMAND] [ARGS...]
Executes COMMAND on every item given by standard input.
Options:
-t Print the command just before it is run
Example:
$ ls | xargs gzip
$ find . -name '*.c' -print | xargs rm
yes
Usage: yes [STRING]...
Repeatedly output a line with all specified STRING(s),
or `y'.
zcat
Usage: zcat [OPTION]... FILE
Uncompress FILE (or stdin if FILE is '-') to stdout.
Options:
-t Test compressed file integrity
Example:
LIBC NSS
GNU Libc uses the Name Service Switch (NSS) to configure the
behavior of the C library for the local environment, and to
configure how it reads system data, such as passwords and group
information. BusyBox has made it Policy that it will never use
NSS, and will never use libc calls that make use of NSS. This
allows you to run an embedded system without the need for
installing an /etc/nsswitch.conf file and without /lib/libnss_*
libraries installed.
If you are using a system that is using a remote LDAP server for
authentication via GNU libc NSS, and you want to use BusyBox,
then you will need to adjust the BusyBox source. Chances are
though, that if you have enough space to install of that stuff
on your system, then you probably want the full GNU utilities.
SEE ALSO
textutils(1),
shellutils(1),
etc...
MAINTAINER
Erik Andersen <andersee@debian.org> <andersen@lineo.com>
AUTHORS
The following people have made significant contributions to
BusyBox -- whether they know it or not.
Erik Andersen <andersee@debian.org>
Edward Betts <edward@debian.org>
John Beppu <beppu@lineo.com>
Brian Candler <B.Candler@pobox.com>
Randolph Chung <tausq@debian.org>
Dave Cinege <dcinege@psychosis.com>
Karl M. Hegbloom <karlheg@debian.org>
Daniel Jacobowitz <dan@debian.org>
Matt Kraai <kraai@alumni.carnegiemellon.edu>
John Lombardo <john@deltanet.com>
Glenn McGrath <bug1@netconnect.com.au>
Bruce Perens <bruce@perens.com>
Chip Rosenthal <chip@unicom.com>, <crosenth@covad.com>
Pavel Roskin <proski@gnu.org>
Gyepi Sam <gyepi@praxis-sw.com>
Linus Torvalds <torvalds@transmeta.com>
Mark Whitley <markw@lineo.com>
Charles P. Wright <cpwright@villagenet.com>
Enrique Zanardi <ezanardi@ull.es>