NAME

BusyBox - The Swiss Army Knife of Embedded Linux

SYNTAX

busybox <applet> [arguments...]  # or

<applet> [arguments...]          # if symlinked

DESCRIPTION

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 GNU coreutils, util-linux, etc. 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 /dev, /etc, and a Linux kernel. BusyBox provides a fairly complete POSIX environment for any small or embedded system.

BusyBox is extremely configurable. This allows you to include only the components you need, thereby reducing binary size. Run 'make config' or 'make menuconfig' to select the functionality that you wish to enable. Then run 'make' to compile BusyBox using your configuration.

After the compile has finished, you should use 'make install' to install BusyBox. This will install the 'bin/busybox' binary, in the target directory specified by CONFIG_PREFIX. CONFIG_PREFIX can be set when configuring BusyBox, or you can specify an alternative location at install time (i.e., with a command line like 'make CONFIG_PREFIX=/tmp/foo install'). If you enabled any applet installation scheme (either as symlinks or hardlinks), these will also be installed in the location pointed to by CONFIG_PREFIX.

USAGE

BusyBox is a multi-call binary. A multi-call binary is an executable program that performs the same job as more than one utility program. That means there is just a single BusyBox binary, but that single binary acts like a large number of utilities. This allows BusyBox to be smaller since all the built-in utility programs (we call them applets) can share code for many common operations.

You can also invoke BusyBox by issuing a command as an argument on the command line. For example, entering

/bin/busybox ls

will also cause BusyBox to behave as 'ls'.

Of course, adding '/bin/busybox' into every command would be painful. So most people will invoke BusyBox using links to the BusyBox binary.

For example, entering

ln -s /bin/busybox ls
./ls

will cause BusyBox to behave as 'ls' (if the 'ls' command has been compiled into BusyBox). Generally speaking, you should never need to make all these links yourself, as the BusyBox build system will do this for you when you run the 'make install' command.

If you invoke BusyBox with no arguments, it will provide you with a list of the applets that have been compiled into your BusyBox binary.

COMMON OPTIONS

Most BusyBox applets support the --help argument to provide a terse runtime description of their behavior. If the CONFIG_FEATURE_VERBOSE_USAGE option has been enabled, more detailed usage information will also be available.

COMMANDS

Currently available applets include:

[, [[, ash, awk, basename, brctl, cat, chgrp, chmod, chown, chroot,
clear, cmp, cp, crond, crontab, cut, date, dd, df, dirname, dmesg,
du, echo, egrep, env, expr, false, fgrep, find, flock, free, fsync,
grep, gunzip, gzip, halt, head, hexdump, hwclock, id, ifconfig, ip,
kill, killall, less, ln, lock, logger, login, ls, md5sum, mkdir,
mkfifo, mknod, mkswap, mktemp, mount, mv, nc, netmsg, netstat, nice,
nslookup, ntpd, passwd, pgrep, pidof, ping, ping6, pivot_root,
poweroff, printf, ps, pwd, readlink, reboot, reset, rm, rmdir,
route, sed, seq, sh, sha256sum, sleep, sort, start-stop-daemon,
strings, swapoff, swapon, switch_root, sync, sysctl, tail, tar, tee,
test, time, top, touch, tr, traceroute, traceroute6, true, udhcpc,
umount, uname, uniq, uptime, vi, wc, which, xargs, yes, zcat

COMMAND DESCRIPTIONS

ash

ash [-il] [-|+Cabefmnuvx] [-|+o OPT]... [-c 'SCRIPT' [ARG0 ARGS] | FILE ARGS | -s ARGS]

Unix shell interpreter

awk

awk [OPTIONS] [AWK_PROGRAM] [FILE]...

-v VAR=VAL      Set variable
-F SEP          Use SEP as field separator
-f FILE         Read program from FILE
-e AWK_PROGRAM

basename

basename FILE [SUFFIX] | -a FILE... | -s SUFFIX FILE...

Strip directory path and SUFFIX from FILE

-a              All arguments are FILEs
-s SUFFIX       Remove SUFFIX (implies -a)

brctl

brctl COMMAND [BRIDGE [ARGS]]

Manage ethernet bridges Commands:

show [BRIDGE]...        Show bridges
addbr BRIDGE            Create BRIDGE
delbr BRIDGE            Delete BRIDGE
addif BRIDGE IFACE      Add IFACE to BRIDGE
delif BRIDGE IFACE      Delete IFACE from BRIDGE
showmacs BRIDGE                 List MAC addresses
showstp BRIDGE                  Show STP info
stp BRIDGE 1/yes/on|0/no/off    Set STP on/off
setageing BRIDGE SECONDS        Set ageing time
setfd BRIDGE SECONDS            Set bridge forward delay
sethello BRIDGE SECONDS         Set hello time
setmaxage BRIDGE SECONDS        Set max message age
setbridgeprio BRIDGE PRIO       Set bridge priority
setportprio BRIDGE IFACE PRIO   Set port priority
setpathcost BRIDGE IFACE COST   Set path cost

cat

cat [FILE]...

Print FILEs to stdout

chgrp

chgrp [-Rh]... GROUP FILE...

Change the group membership of FILEs to GROUP

-h      Affect symlinks instead of symlink targets
-R      Recurse

chmod

chmod [-R] MODE[,MODE]... FILE...

MODE is octal number (bit pattern sstrwxrwxrwx) or [ugoa]{+|-|=}[rwxXst]

-R      Recurse

chown

chown [-Rh]... USER[:[GRP]] FILE...

Change the owner and/or group of FILEs to USER and/or GRP

-h      Affect symlinks instead of symlink targets
-R      Recurse

chroot

chroot NEWROOT [PROG ARGS]

Run PROG with root directory set to NEWROOT

clear

clear

Clear screen

cmp

cmp [-ls] [-n NUM] FILE1 [FILE2]

Compare FILE1 with FILE2 (or stdin)

-l      Write the byte numbers (decimal) and values (octal)
        for all differing bytes
-s      Quiet
-n NUM  Compare at most NUM bytes

cp

cp [-arPLHpfinlsTu] SOURCE DEST or: cp [-arPLHpfinlsu] SOURCE... { -t DIRECTORY | DIRECTORY }

Copy SOURCEs to DEST

-a      Same as -dpR
-R,-r   Recurse
-d,-P   Preserve symlinks (default if -R)
-L      Follow all symlinks
-H      Follow symlinks on command line
-p      Preserve file attributes if possible
-f      Overwrite
-i      Prompt before overwrite
-n      Don't overwrite
-l,-s   Create (sym)links
-T      Refuse to copy if DEST is a directory
-t DIR  Copy all SOURCEs into DIR
-u      Copy only newer files

crond

crond [-fbS] [-l N] [-L LOGFILE] [-c DIR]

-f      Foreground
-b      Background (default)
-S      Log to syslog (default)
-l N    Set log level. Most verbose 0, default 8
-L FILE Log to FILE
-c DIR  Cron dir. Default:/etc/crontabs

crontab

crontab [-c DIR] [-u USER] [-ler]|[FILE]

-c      Crontab directory
-u      User
-l      List crontab
-e      Edit crontab
-r      Delete crontab
FILE    Replace crontab by FILE ('-': stdin)

cut

cut [OPTIONS] [FILE]...

Print selected fields from FILEs to stdout

-b LIST Output only bytes from LIST
-c LIST Output only characters from LIST
-d SEP  Field delimiter for input (default -f TAB, -F run of whitespace)
-O SEP  Field delimeter for output (default = -d for -f, one space for -F)
-D      Don't sort/collate sections or match -fF lines without delimeter
-f LIST Print only these fields (-d is single char)
-s      Output only lines containing delimiter
-n      Ignored

date

date [OPTIONS] [+FMT] [[-s] TIME]

Display time (using +FMT), or set time

-u              Work in UTC (don't convert to local time)
[-s] TIME       Set time to TIME
-d TIME         Display TIME, not 'now'
-D FMT          FMT (strptime format) for -s/-d TIME conversion
-r FILE         Display last modification time of FILE
-R              Output RFC-2822 date
-I[SPEC]        Output ISO-8601 date
                SPEC=date (default), hours, minutes, seconds or ns

Recognized TIME formats:

@seconds_since_1970
hh:mm[:ss]
[YYYY.]MM.DD-hh:mm[:ss]
YYYY-MM-DD hh:mm[:ss]
[[[[[YY]YY]MM]DD]hh]mm[.ss]

dd

dd [if=FILE] [of=FILE] [ibs=N obs=N/bs=N] [count=N] [skip=N] [seek=N] [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes|count_bytes|fullblock|direct] [oflag=seek_bytes|append|direct]

Copy a file with converting and formatting

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
ibs=N           Read N bytes at a time
obs=N           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
conv=notrunc    Don't truncate output file
conv=noerror    Continue after read errors
conv=sync       Pad blocks with zeros
conv=fsync      Physically write data out before finishing
conv=swab       Swap every pair of bytes
iflag=skip_bytes        skip=N is in bytes
iflag=count_bytes       count=N is in bytes
oflag=seek_bytes        seek=N is in bytes
iflag=direct    O_DIRECT input
oflag=direct    O_DIRECT output
iflag=fullblock Read full blocks
oflag=append    Open output in append mode

N may be suffixed by c (1), w (2), b (512), kB (1000), k (1024), MB, M, GB, G

df

df [-PkmhT] [-t TYPE] [FILESYSTEM]...

Print filesystem usage statistics

-P      POSIX output format
-k      1024-byte blocks (default)
-m      1M-byte blocks
-h      Human readable (e.g. 1K 243M 2G)
-T      Print filesystem type
-t TYPE Print only mounts of this type

dirname

dirname FILENAME

Strip non-directory suffix from FILENAME

dmesg

dmesg [-cr] [-n LEVEL] [-s SIZE]

Print or control the kernel ring buffer

-c              Clear ring buffer after printing
-n LEVEL        Set console logging level
-s SIZE         Buffer size
-r              Print raw message buffer

du

du [-aHLdclsxhmk] [FILE]...

Summarize disk space used for FILEs (or directories)

-a      Show file sizes too
-b      Apparent size (including holes)
-L      Follow all symlinks
-H      Follow symlinks on command line
-d N    Limit output to directories (and files with -a) of depth < N
-c      Show grand total
-l      Count sizes many times if hard linked
-s      Display only a total for each argument
-x      Skip directories on different filesystems
-h      Sizes in human readable format (e.g., 1K 243M 2G)
-m      Sizes in megabytes
-k      Sizes in kilobytes (default)

echo

echo [-neE] [ARG]...

Print ARGs to stdout

-n      No trailing newline
-e      Interpret backslash escapes (\t=tab etc)
-E      Don't interpret backslash escapes (default)

env

env [-i0] [-u NAME]... [-] [NAME=VALUE]... [PROG ARGS]

Print current environment or run PROG after setting up environment

-, -i   Start with empty environment
-0      NUL terminated output
-u NAME Remove variable from environment

expr

expr EXPRESSION

Print the value of EXPRESSION

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     1 if ARG1 is less than ARG2, else 0. Similarly:
ARG1 <= ARG2
ARG1 = ARG2
ARG1 != ARG2
ARG1 >= ARG2
ARG1 > ARG2
ARG1 + ARG2     Sum of ARG1 and ARG2. Similarly:
ARG1 - ARG2
ARG1 * ARG2
ARG1 / ARG2
ARG1 % ARG2
STRING : REGEXP         Anchored pattern match of REGEXP in STRING
match STRING REGEXP     Same as STRING : REGEXP
substr STRING POS LEN   Substring of STRING, POS counts 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.

find

find [-HL] [PATH]... [OPTIONS] [ACTIONS]

Search for files and perform actions on them. First failed action stops processing of current file. Defaults: PATH is current directory, action is '-print'

-L,-follow      Follow symlinks
-H              ...on command line only
-xdev           Don't descend directories on other filesystems
-maxdepth N     Descend at most N levels. -maxdepth 0 applies
                actions to command line arguments only
-mindepth N     Don't act on first N levels
-depth          Act on directory *after* traversing it

Actions:

        ( ACTIONS )     Group actions for -o / -a
        ! ACT           Invert ACT's success/failure
        ACT1 [-a] ACT2  If ACT1 fails, stop, else do ACT2
        ACT1 -o ACT2    If ACT1 succeeds, stop, else do ACT2
                        Note: -a has higher priority than -o
        -name PATTERN   Match file name (w/o directory name) to PATTERN
        -iname PATTERN  Case insensitive -name
        -path PATTERN   Match path to PATTERN
        -ipath PATTERN  Case insensitive -path
        -regex PATTERN  Match path to regex PATTERN
        -type X         File type is X (one of: f,d,l,b,c,s,p)
        -perm MASK      At least one mask bit (+MASK), all bits (-MASK),
                        or exactly MASK bits are set in file's mode
        -mtime DAYS     mtime is greater than (+N), less than (-N),
                        or exactly N days in the past
        -mmin MINS      mtime is greater than (+N), less than (-N),
                        or exactly N minutes in the past
        -newer FILE     mtime is more recent than FILE's
        -user NAME/ID   File is owned by given user
        -group NAME/ID  File is owned by given group
        -size N[bck]    File size is N (c:bytes,k:kbytes,b:512 bytes(def.))
                        +/-N: file size is bigger/smaller than N
        -prune          If current file is directory, don't descend into it
If none of the following actions is specified, -print is assumed
        -print          Print file name
        -print0         Print file name, NUL terminated
        -exec CMD ARG ; Run CMD with all instances of {} replaced by
                        file name. Fails if CMD exits with nonzero

flock

flock [-sxun] FD | { FILE [-c] PROG ARGS }

[Un]lock file descriptor, or lock FILE, run PROG

-s      Shared lock
-x      Exclusive lock (default)
-u      Unlock FD
-n      Fail rather than wait

free

free

Display free and used memory

fsync

fsync [-d] FILE...

Write all buffered blocks in FILEs to disk

-d      Avoid syncing metadata

grep

grep [-HhnlLoqvsrRiwFE] [-m N] [-A|B|C N] { PATTERN | -e PATTERN... | -f FILE... } [FILE]...

Search for PATTERN in FILEs (or stdin)

-H      Add 'filename:' prefix
-h      Do not add 'filename:' prefix
-n      Add 'line_no:' prefix
-l      Show only names of files that match
-L      Show only names of files that don't match
-c      Show only count of matching lines
-o      Show only the matching part of line
-q      Quiet. Return 0 if PATTERN is found, 1 otherwise
-v      Select non-matching lines
-s      Suppress open and read errors
-r      Recurse
-R      Recurse and dereference symlinks
-i      Ignore case
-w      Match whole words only
-x      Match whole lines only
-F      PATTERN is a literal (not regexp)
-E      PATTERN is an extended regexp
-m N    Match up to N times per file
-A N    Print N lines of trailing context
-B N    Print N lines of leading context
-C N    Same as '-A N -B N'
-e PTRN Pattern to match
-f FILE Read pattern from file

gunzip

gunzip [-cfkt] [FILE]...

Decompress FILEs (or stdin)

-c      Write to stdout
-f      Force
-k      Keep input files
-t      Test integrity

gzip

gzip [-cfkdt] [FILE]...

Compress FILEs (or stdin)

-d      Decompress
-c      Write to stdout
-f      Force
-k      Keep input files
-t      Test integrity

halt

halt [-d DELAY] [-nf]

Halt the system

-d SEC  Delay interval
-n      Do not sync
-f      Force (don't go through init)

head

head [OPTIONS] [FILE]...

Print first 10 lines of FILEs (or stdin). With more than one FILE, precede each with a filename header.

-n N[bkm]       Print first N lines
-n -N[bkm]      Print all except N last lines
-c [-]N[bkm]    Print first N bytes
                (b:*512 k:*1024 m:*1024^2)
-q              Never print headers
-v              Always print headers

hexdump

hexdump [-bcdoxCv] [-e FMT] [-f FMT_FILE] [-n LEN] [-s OFS] [FILE]...

Display FILEs (or stdin) in a user specified format

-b              1-byte octal display
-c              1-byte character display
-d              2-byte decimal display
-o              2-byte octal display
-x              2-byte hex display
-C              hex+ASCII 16 bytes per line
-v              Show all (no dup folding)
-e FORMAT_STR   Example: '16/1 "%02x|""\n"'
-f FORMAT_FILE
-n LENGTH       Show only first LENGTH bytes
-s OFFSET       Skip OFFSET bytes

hwclock

hwclock [-swul] [--systz] [-f DEV]

Show or set hardware clock (RTC)

-s      Set system time from RTC
-w      Set RTC from system time
--systz Set in-kernel timezone, correct system time
        if RTC is kept in local time
-f DEV  Use specified device (e.g. /dev/rtc2)
-u      Assume RTC is kept in UTC
-l      Assume RTC is kept in local time
        (if neither is given, read from /etc/adjtime)

id

id [-ugGnr] [USER]

Print information about USER or the current user

-u      User ID
-g      Group ID
-G      Supplementary group IDs
-n      Print names instead of numbers
-r      Print real ID instead of effective ID

ifconfig

ifconfig [-a] [IFACE] [ADDRESS]

Configure a network interface

[add ADDRESS[/PREFIXLEN]]
[del ADDRESS[/PREFIXLEN]]
[[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]]
[netmask ADDRESS] [dstaddr ADDRESS]
[hw ether ADDRESS] [metric NN] [mtu NN]
[[-]trailers] [[-]arp] [[-]allmulti]
[multicast] [[-]promisc] [txqueuelen NN] [[-]dynamic]
[up|down] ...

ip

ip [OPTIONS] address|route|link|neigh|rule [ARGS]

OPTIONS := -f[amily] inet|inet6|link | -o[neline]

ip addr add|del IFADDR dev IFACE | show|flush [dev IFACE] [to PREFIX] ip route list|flush|add|del|change|append|replace|test ROUTE ip link set IFACE [up|down] [arp on|off] [multicast on|off] [promisc on|off] [mtu NUM] [name NAME] [qlen NUM] [address MAC] [master IFACE | nomaster] [netns PID] ip neigh show|flush [to PREFIX] [dev DEV] [nud STATE] ip rule [list] | add|del SELECTOR ACTION

kill

kill [-l] [-SIG] PID...

Send a signal (default: TERM) to given PIDs

-l      List all signal names and numbers

killall

killall [-lq] [-SIG] PROCESS_NAME...

Send a signal (default: TERM) to given processes

-l      List all signal names and numbers
-q      Don't complain if no processes were killed

less

less [-EFNh~] [FILE]...

View FILE (or stdin) one screenful at a time

-E      Quit once the end of a file is reached
-F      Quit if entire file fits on first screen
-N      Prefix line number to each line
-~      Suppress ~s displayed past EOF

ln

ln [-sfnbtv] [-S SUF] TARGET... LINK|DIR

Create a link LINK or DIR/TARGET to the specified TARGET(s)

-s      Make symlinks instead of hardlinks
-f      Remove existing destinations
-n      Don't dereference symlinks - treat like normal file
-b      Make a backup of the target (if exists) before link operation
-S SUF  Use suffix instead of ~ when making backup files
-T      Treat LINK as a file, not DIR
-v      Verbose

logger

logger [-s] [-t TAG] [-p PRIO] [MESSAGE]

Write MESSAGE (or stdin) to syslog

-s      Log to stderr as well as the system log
-t TAG  Log using the specified tag (defaults to user name)
-p PRIO Priority (number or FACILITY.LEVEL pair)

login

login [-p] [-h HOST] [[-f] USER]

Begin a new session on the system

-f      Don't authenticate (user already authenticated)
-h HOST Host user came from (for network logins)
-p      Preserve environment

$LOGIN_TIMEOUT Seconds (default 60, 0 - disable)

ls

ls [-1AaCxdLHRFplinshrSXvctu] [-w WIDTH] [FILE]...

List directory contents

-1      One column output
-a      Include names starting with .
-A      Like -a, but exclude . and ..
-x      List by lines
-d      List directory names, not contents
-L      Follow symlinks
-H      Follow symlinks on command line
-R      Recurse
-p      Append / to directory names
-F      Append indicator (one of */=@|) to names
-l      Long format
-i      List inode numbers
-n      List numeric UIDs and GIDs instead of names
-s      List allocated blocks
-lc     List ctime
-lu     List atime
--full-time     List full date/time
-h      Human readable sizes (1K 243M 2G)
--group-directories-first
-S      Sort by size
-X      Sort by extension
-v      Sort by version
-t      Sort by mtime
-tc     Sort by ctime
-tu     Sort by atime
-r      Reverse sort order
-w N    Format N columns wide
--color[={always,never,auto}]

md5sum

md5sum [-c[sw]] [FILE]...

Print or check MD5 checksums

-c      Check sums against list in FILEs
-s      Don't output anything, status code shows success
-w      Warn about improperly formatted checksum lines

mkdir

mkdir [-m MODE] [-p] DIRECTORY...

Create DIRECTORY

-m MODE Mode
-p      No error if exists; make parent directories as needed

mkfifo

mkfifo [-m MODE] NAME

Create named pipe

-m MODE Mode (default a=rw)

mknod

mknod [-m MODE] NAME TYPE [MAJOR MINOR]

Create a special file (block, character, or pipe)

        -m MODE Creation mode (default a=rw)
TYPE:
        b       Block device
        c or u  Character device
        p       Named pipe (MAJOR MINOR must be omitted)

mkswap

mkswap [-L LBL] BLOCKDEV [KBYTES]

Prepare BLOCKDEV to be used as swap partition

-L LBL  Label

mktemp

mktemp [-dt] [-p DIR] [TEMPLATE]

Create a temporary file with name based on TEMPLATE and print its name. TEMPLATE must end with XXXXXX (e.g. [/dir/]nameXXXXXX). Without TEMPLATE, -t tmp.XXXXXX is assumed.

-d      Make directory, not file
-q      Fail silently on errors
-t      Prepend base directory name to TEMPLATE
-p DIR  Use DIR as a base directory (implies -t)
-u      Do not create anything; print a name

Base directory is: -p DIR, else $TMPDIR, else /tmp

mount

mount [OPTIONS] [-o OPT] DEVICE NODE

Mount a filesystem. Filesystem autodetection requires /proc.

        -a              Mount all filesystems in fstab
        -i              Don't run mount helper
        -r              Read-only mount
        -t FSTYPE[,...] Filesystem type(s)
        -O OPT          Mount only filesystems with option OPT (-a only)
-o OPT:
        loop            Ignored (loop devices are autodetected)
        [a]sync         Writes are [a]synchronous
        [no]atime       Disable/enable updates to inode access times
        [no]diratime    Disable/enable atime updates to directories
        [no]relatime    Disable/enable atime updates relative to modification time
        [no]dev         (Dis)allow use of special device files
        [no]exec        (Dis)allow use of executable files
        [no]suid        (Dis)allow set-user-id-root programs
        [r]shared       Convert [recursively] to a shared subtree
        [r]slave        Convert [recursively] to a slave subtree
        [r]private      Convert [recursively] to a private subtree
        [un]bindable    Make mount point [un]able to be bind mounted
        [r]bind         Bind a file or directory [recursively] to another location
        move            Relocate an existing mount point
        remount         Remount a mounted filesystem, changing flags
        ro              Same as -r

There are filesystem-specific -o flags.

mv

mv [-finT] SOURCE DEST or: mv [-fin] SOURCE... { -t DIRECTORY | DIRECTORY }

Rename SOURCE to DEST, or move SOURCEs to DIRECTORY

-f      Don't prompt before overwriting
-i      Interactive, prompt before overwrite
-n      Don't overwrite an existing file
-T      Refuse to move if DEST is a directory
-t DIR  Move all SOURCEs into DIR

nc

nc [IPADDR PORT]

Open a pipe to IP:PORT

netstat

netstat [-ral] [-tuwx] [-enWp]

Display networking information

-r      Routing table
-a      All sockets
-l      Listening sockets
        Else: connected sockets
-t      TCP sockets
-u      UDP sockets
-w      Raw sockets
-x      Unix sockets
        Else: all socket types
-e      Other/more information
-n      Don't resolve names
-W      Wide display
-p      Show PID/program name for sockets

nice

nice [-n ADJUST] [PROG ARGS]

Change scheduling priority, run PROG

-n ADJUST       Adjust priority by ADJUST

nslookup

nslookup [-type=QUERY_TYPE] [-debug] HOST [DNS_SERVER]

Query DNS about HOST

QUERY_TYPE: soa,ns,a,aaaa,cname,mx,txt,ptr,srv,any

ntpd

ntpd [-dnqNwl] [-I IFACE] [-S PROG] [-p PEER]...

NTP client/server

-d[d]   Verbose
-n      Run in foreground
-q      Quit after clock is set
-N      Run at high priority
-w      Do not set time (only query peers), implies -n
-S PROG Run PROG after stepping time, stratum change, and every 11 min
-p PEER Obtain time from PEER (may be repeated)
-l      Also run as server on port 123
-I IFACE Bind server to IFACE, implies -l

passwd

passwd [-a ALG] [-dlu] [USER]

Change USER's password (default: current user)

-a ALG  des,md5,sha256/512 (default md5)
-d      Set password to ''
-l      Lock (disable) account
-u      Unlock (enable) account

pgrep

pgrep [-flanovx] [-s SID|-P PPID|PATTERN]

Display process(es) selected by regex PATTERN

-l      Show command name too
-a      Show command line too
-f      Match against entire command line
-n      Show the newest process only
-o      Show the oldest process only
-v      Negate the match
-x      Match whole name (not substring)
-s      Match session ID (0 for current)
-P      Match parent process ID

pidof

pidof [NAME]...

List PIDs of all processes with names that match NAMEs

ping

ping [OPTIONS] HOST

Send ICMP ECHO_REQUESTs to HOST

-4,-6           Force IP or IPv6 name resolution
-c CNT          Send only CNT pings
-s SIZE         Send SIZE data bytes in packets (default 56)
-i SECS         Interval
-A              Ping as soon as reply is recevied
-t TTL          Set TTL
-I IFACE/IP     Source interface or IP address
-W SEC          Seconds to wait for the first response (default 10)
                (after all -c CNT packets are sent)
-w SEC          Seconds until ping exits (default:infinite)
                (can exit earlier with -c CNT)
-q              Quiet, only display output at start/finish
-p HEXBYTE      Payload pattern

ping6

ping6 [OPTIONS] HOST

Send ICMP ECHO_REQUESTs to HOST

-c CNT          Send only CNT pings
-s SIZE         Send SIZE data bytes in packets (default 56)
-i SECS         Interval
-A              Ping as soon as reply is recevied
-I IFACE/IP     Source interface or IP address
-W SEC          Seconds to wait for the first response (default 10)
                (after all -c CNT packets are sent)
-w SEC          Seconds until ping exits (default:infinite)
                (can exit earlier with -c CNT)
-q              Quiet, only display output at start/finish
-p HEXBYTE      Payload pattern

pivot_root

pivot_root NEW_ROOT PUT_OLD

Move the current root file system to PUT_OLD and make NEW_ROOT the new root file system

poweroff

poweroff [-d DELAY] [-nf]

Halt and shut off power

-d SEC  Delay interval
-n      Do not sync
-f      Force (don't go through init)

printf

printf FORMAT [ARG]...

Format and print ARG(s) according to FORMAT (a-la C printf)

ps

ps

Show list of processes

w       Wide output

pwd

pwd

Print the full filename of the current working directory

readlink

readlink [-fnv] FILE

Display the value of a symlink

-f      Canonicalize by following all symlinks
-n      Don't add newline
-v      Verbose

reboot

reboot [-d DELAY] [-nf]

Reboot the system

-d SEC  Delay interval
-n      Do not sync
-f      Force (don't go through init)

reset

reset

Reset the screen

rm

rm [-irf] FILE...

Remove (unlink) FILEs

-i      Always prompt before removing
-f      Never prompt
-R,-r   Recurse

rmdir

rmdir [-p] DIRECTORY...

Remove DIRECTORY if it is empty

-p      Include parents
--ignore-fail-on-non-empty

route

route [-ne] [-A inet[6]] [{add|del} [-net|-host] TARGET [netmask MASK] [gw GATEWAY] [metric N] [mss BYTES] [window BYTES] [reject] [IFACE]]

Show or edit kernel routing tables

-n      Don't resolve names
-e      Display other/more information
-A inet[6]      Select address family

sed

sed [-i[SFX]] [-nrE] [-f FILE]... [-e CMD]... [FILE]... or: sed [-i[SFX]] [-nrE] CMD [FILE]...

-e CMD  Add CMD to sed commands to be executed
-f FILE Add FILE contents to sed commands to be executed
-i[SFX] Edit files in-place (otherwise write to stdout)
        Optionally back files up, appending SFX
-n      Suppress automatic printing of pattern space
-r,-E   Use extended regex syntax

If no -e or -f, the first non-option argument is the sed command string. Remaining arguments are input files (stdin if none).

seq

seq [-w] [-s SEP] [FIRST [INC]] LAST

Print numbers from FIRST to LAST, in steps of INC. FIRST, INC default to 1.

-w      Pad to last with leading zeros
-s SEP  String separator

sh

sh [-il] [-|+Cabefmnuvx] [-|+o OPT]... [-c 'SCRIPT' [ARG0 ARGS] | FILE ARGS | -s ARGS]

Unix shell interpreter

sha256sum

sha256sum [-c[sw]] [FILE]...

Print or check SHA256 checksums

-c      Check sums against list in FILEs
-s      Don't output anything, status code shows success
-w      Warn about improperly formatted checksum lines

sleep

sleep [N]...

Pause for a time equal to the total of the args given, where each arg can have an optional suffix of (s)econds, (m)inutes, (h)ours, or (d)ays

sort

sort [-nru] [FILE]...

Sort lines of text

-n      Sort numbers
-r      Reverse sort order
-s      Stable (don't sort ties alphabetically)
-u      Suppress duplicate lines
-z      NUL terminated input and output

start-stop-daemon

start-stop-daemon [OPTIONS] [-S|-K] ... [-- ARGS...]

Search for matching processes, and then -K: stop all matching processes -S: start a process unless a matching process is found

Process matching:

        -u USERNAME|UID Match only this user's processes
        -n NAME         Match processes with NAME
                        in comm field in /proc/PID/stat
        -x EXECUTABLE   Match processes with this command
                        in /proc/PID/cmdline
        -p FILE         Match a process with PID from FILE
        All specified conditions must match
-S only:
        -x EXECUTABLE   Program to run
        -a NAME         Zeroth argument
        -b              Background
        -c USER[:[GRP]] Change user/group
        -m              Write PID to pidfile specified by -p
-K only:
        -s SIG          Signal to send
        -t              Match only, exit with 0 if found
Other:

        -q              Quiet

strings

strings [-fo] [-t o|d|x] [-n LEN] [FILE]...

Display printable strings in a binary file

-f              Precede strings with filenames
-o              Precede strings with octal offsets
-t o|d|x        Precede strings with offsets in base 8/10/16
-n LEN          At least LEN characters form a string (default 4)

swapoff

swapoff [-a] [DEVICE]

Stop swapping on DEVICE

-a      Stop swapping on all swap devices

swapon

swapon [-a] [-e] [-d[POL]] [-p PRI] [DEVICE]

Start swapping on DEVICE

-a      Start swapping on all swap devices
-d[POL] Discard blocks at swapon (POL=once),
        as freed (POL=pages), or both (POL omitted)
-e      Silently skip devices that do not exist
-p PRI  Set swap device priority

switch_root

switch_root [-c CONSOLE_DEV] NEW_ROOT NEW_INIT [ARGS]

Free initramfs and switch to another root fs:

chroot to NEW_ROOT, delete all in /, move NEW_ROOT to /, execute NEW_INIT. PID must be 1. NEW_ROOT must be a mountpoint.

-c DEV  Reopen stdio to DEV after switch

sync

sync

Write all buffered blocks to disk

sysctl

sysctl [-enq] { -a | -p [FILE]... | [-w] [KEY[=VALUE]]... }

Show/set kernel parameters

-e      Don't warn about unknown keys
-n      Don't show key names
-q      Quiet
-a      Show all values
-p      Set values from FILEs (default /etc/sysctl.conf)
-w      Set values

tail

tail [OPTIONS] [FILE]...

Print last 10 lines of FILEs (or stdin) to. With more than one FILE, precede each with a filename header.

-c [+]N[bkm]    Print last N bytes
-n N[bkm]       Print last N lines
-n +N[bkm]      Start on Nth line and print the rest
                (b:*512 k:*1024 m:*1024^2)
-q              Never print headers
-v              Always print headers
-f              Print data as file grows
-F              Same as -f, but keep retrying
-s SECONDS      Wait SECONDS between reads with -f

tar

tar c|x|t [-zahvokO] [-f TARFILE] [-C DIR] [-T FILE] [-X FILE] [FILE]...

Create, extract, or list files from a tar file

c       Create
x       Extract
t       List
-f FILE Name of TARFILE ('-' for stdin/out)
-C DIR  Change to DIR before operation
-v      Verbose
-O      Extract to stdout
-o      Don't restore user:group
-k      Don't replace existing files
-z      (De)compress using gzip
-a      (De)compress based on extension
-h      Follow symlinks
-T FILE File with names to include
-X FILE File with glob patterns to exclude

tee

tee [-ai] [FILE]...

Copy stdin to each FILE, and also to stdout

-a      Append to the given FILEs, don't overwrite
-i      Ignore interrupt signals (SIGINT)

time

time [-vpa] [-o FILE] PROG ARGS

Run PROG, display resource usage when it exits

-v      Verbose
-p      POSIX output format
-f FMT  Custom format
-o FILE Write result to FILE
-a      Append (else overwrite)

top

top [-b] [-n COUNT] [-d SECONDS]

Show a view of process activity in real time. Read the status of all processes from /proc each SECONDS and show a screenful of them.

-b      Batch mode
-n N    Exit after N iterations
-d SEC  Delay between updates

touch

touch [-cham] [-d DATE] [-t DATE] [-r FILE] FILE...

Update mtime of FILEs

-c      Don't create files
-h      Don't follow links
-a      Change only atime
-m      Change only mtime
-d DT   Date/time to use
-t DT   Date/time to use
-r FILE Use FILE's date/time

tr

tr [-cds] STRING1 [STRING2]

Translate, squeeze, or delete characters from stdin, writing to stdout

-c      Take complement of STRING1
-d      Delete input characters coded STRING1
-s      Squeeze multiple output characters of STRING2 into one character

traceroute

traceroute [-46Flnrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT] [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE] [-z PAUSE_MSEC] HOST [BYTES]

Trace the route to HOST

-4,-6   Force IP or IPv6 name resolution
-F      Set don't fragment bit
-l      Display TTL value of the returned packet
-n      Print numeric addresses
-r      Bypass routing tables, send directly to HOST
-v      Verbose
-f N    First number of hops (default 1)
-m N    Max number of hops
-q N    Number of probes per hop (default 3)
-p N    Base UDP port number used in probes
        (default 33434)
-s IP   Source address
-i IFACE Source interface
-t N    Type-of-service in probe packets (default 0)
-w SEC  Wait for a response (default 3)
-z MSEC Wait before each send

traceroute6

traceroute6 [-nrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT] [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE] [-z PAUSE_MSEC] HOST [BYTES]

Trace the route to HOST

-n      Print numeric addresses
-r      Bypass routing tables, send directly to HOST
-v      Verbose
-f N    First number of hops (default 1)
-m N    Max number of hops
-q N    Number of probes per hop (default 3)
-p N    Base UDP port number used in probes
        (default 33434)
-s IP   Source address
-i IFACE Source interface
-t N    Type-of-service in probe packets (default 0)
-w SEC  Wait for a response (default 3)
-z MSEC Wait before each send

udhcpc

udhcpc [-fbqRB] [-t N] [-T SEC] [-A SEC|-n] [-i IFACE] [-s PROG] [-p PIDFILE] [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]...

        -i IFACE        Interface to use (default )
        -s PROG         Run PROG at DHCP events (default /usr/share/udhcpc/default.script)
        -p FILE         Create pidfile
        -B              Request broadcast replies
        -t N            Send up to N discover packets (default 3)
        -T SEC          Pause between packets (default 3)
        -A SEC          Wait if lease is not obtained (default 20)
        -b              Background if lease is not obtained
        -n              Exit if lease is not obtained
        -q              Exit after obtaining lease
        -R              Release IP on exit
        -f              Run in foreground
        -S              Log to syslog too
        -r IP           Request this IP address
        -o              Don't request any options (unless -O is given)
        -O OPT          Request option OPT from server (cumulative)
        -x OPT:VAL      Include option OPT in sent packets (cumulative)
                        Examples of string, numeric, and hex byte opts:
                        -x hostname:bbox - option 12
                        -x lease:3600 - option 51 (lease time)
                        -x 0x3d:0100BEEFC0FFEE - option 61 (client id)
                        -x 14:'"dumpfile"' - option 14 (shell-quoted)
        -F NAME         Ask server to update DNS mapping for NAME
        -V VENDOR       Vendor identifier (default 'udhcp VERSION')
        -C              Don't send MAC as client identifier
Signals:

        USR1    Renew lease
        USR2    Release lease

umount

umount [-rlfda] [-t FSTYPE] FILESYSTEM|DIRECTORY

Unmount filesystems

-a      Unmount all filesystems
-r      Remount devices read-only if mount is busy
-l      Lazy umount (detach filesystem)
-f      Force umount (i.e., unreachable NFS server)
-d      Free loop device if it has been used
-t FSTYPE[,...] Unmount only these filesystem type(s)

uname

uname [-amnrspvio]

Print system information

-a      Print all
-m      Machine (hardware) type
-n      Hostname
-r      Kernel release
-s      Kernel name (default)
-p      Processor type
-v      Kernel version
-i      Hardware platform
-o      OS name

uniq

uniq [-cduiz] [-f,s,w N] [FILE [OUTFILE]]

Discard duplicate lines

-c      Prefix lines by the number of occurrences
-d      Only print duplicate lines
-u      Only print unique lines
-i      Ignore case
-z      NUL terminated output
-f N    Skip first N fields
-s N    Skip first N chars (after any skipped fields)
-w N    Compare N characters in line

uptime

uptime

Display the time since the last boot

vi

vi [-c CMD] [-R] [-H] [FILE]...

Edit FILE

-c CMD  Initial command to run ($EXINIT and ~/.exrc also available)
-R      Read-only
-H      List available features

wc

wc [-clwL] [FILE]...

Count lines, words, and bytes for FILEs (or stdin)

-c      Count bytes
-l      Count newlines
-w      Count words
-L      Print longest line length

which

which [-a] COMMAND...

Locate COMMAND

-a      Show all matches

xargs

xargs [OPTIONS] [PROG ARGS]

Run PROG on every item given by stdin

-0      NUL terminated input
-r      Don't run command if input is empty
-t      Print the command on stderr before execution
-p      Ask user whether to run each command
-E STR,-e[STR]  STR stops input processing
-n N    Pass no more than N args to PROG
-s N    Pass command line of no more than N bytes
-x      Exit if size is exceeded

yes

yes [STRING]

Repeatedly print a line with STRING, or 'y'

zcat

zcat [FILE]...

Decompress to stdout

LIBC NSS

GNU Libc (glibc) 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. This is implemented using an /etc/nsswitch.conf configuration file, and using one or more of the /lib/libnss_* libraries. BusyBox tries to avoid using any libc calls that make use of NSS. Some applets however, such as login and su, will use libc functions that require NSS.

If you enable CONFIG_USE_BB_PWD_GRP, BusyBox will use internal functions to directly access the /etc/passwd, /etc/group, and /etc/shadow files without using NSS. This may allow you to run your system without the need for installing any of the NSS configuration files and libraries.

When used with glibc, the BusyBox 'networking' applets will similarly require that you install at least some of the glibc NSS stuff (in particular, /etc/nsswitch.conf, /lib/libnss_dns*, /lib/libnss_files*, and /lib/libresolv*).

Shameless Plug: As an alternative, one could use a C library such as uClibc. In addition to making your system significantly smaller, uClibc does not require the use of any NSS support files or libraries.

MAINTAINER

Denis Vlasenko <vda.linux@googlemail.com>

AUTHORS

The following people have contributed code to BusyBox whether they know it or not. If you have written code included in BusyBox, you should probably be listed here so you can obtain your bit of eternal glory. If you should be listed here, or the description of what you have done needs more detail, or is incorrect, please send in an update.

Emanuele Aina <emanuele.aina@tiscali.it>

run-parts

Erik Andersen <andersen@codepoet.org>

Tons of new stuff, major rewrite of most of the
core apps, tons of new apps as noted in header files.
Lots of tedious effort writing these boring docs that
nobody is going to actually read.

Laurence Anderson <l.d.anderson@warwick.ac.uk>

rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm

Jeff Angielski <jeff@theptrgroup.com>

ftpput, ftpget

Edward Betts <edward@debian.org>

expr, hostid, logname, whoami

John Beppu <beppu@codepoet.org>

du, nslookup, sort

Brian Candler <B.Candler@pobox.com>

tiny-ls(ls)

Randolph Chung <tausq@debian.org>

fbset, ping, hostname

Dave Cinege <dcinege@psychosis.com>

more(v2), makedevs, dutmp, modularization, auto links file,
various fixes, Linux Router Project maintenance

Jordan Crouse <jordan@cosmicpenguin.net>

ipcalc

Magnus Damm <damm@opensource.se>

tftp client insmod powerpc support

Larry Doolittle <ldoolitt@recycle.lbl.gov>

pristine source directory compilation, lots of patches and fixes.

Glenn Engel <glenne@engel.org>

httpd

Gennady Feldman <gfeldman@gena01.com>

Sysklogd (single threaded syslogd, IPC Circular buffer support,
logread), various fixes.

Karl M. Hegbloom <karlheg@debian.org>

cp_mv.c, the test suite, various fixes to utility.c, &c.

Daniel Jacobowitz <dan@debian.org>

mktemp.c

Matt Kraai <kraai@alumni.cmu.edu>

documentation, bugfixes, test suite

Stephan Linz <linz@li-pro.net>

ipcalc, Red Hat equivalence

John Lombardo <john@deltanet.com>

tr

Glenn McGrath <bug1@iinet.net.au>

Common unarchiving code and unarchiving applets, ifupdown, ftpgetput,
nameif, sed, patch, fold, install, uudecode.
Various bugfixes, review and apply numerous patches.

Manuel Novoa III <mjn3@codepoet.org>

cat, head, mkfifo, mknod, rmdir, sleep, tee, tty, uniq, usleep, wc, yes,
mesg, vconfig, make_directory, parse_mode, dirname, mode_string,
get_last_path_component, simplify_path, and a number trivial libbb routines

also bug fixes, partial rewrites, and size optimizations in
ash, basename, cal, cmp, cp, df, du, echo, env, ln, logname, md5sum, mkdir,
mv, realpath, rm, sort, tail, touch, uname, watch, arith, human_readable,
interface, dutmp, ifconfig, route

Vladimir Oleynik <dzo@simtreas.ru>

cmdedit; xargs(current), httpd(current);
ports: ash, crond, fdisk, inetd, stty, traceroute, top;
locale, various fixes
and irreconcilable critic of everything not perfect.

Bruce Perens <bruce@pixar.com>

Original author of BusyBox in 1995, 1996. Some of his code can
still be found hiding here and there...

Tim Riker <Tim@Rikers.org>

bug fixes, member of fan club

Kent Robotti <robotti@metconnect.com>

reset, tons and tons of bug reports and patches.

Chip Rosenthal <chip@unicom.com>, <crosenth@covad.com>

wget - Contributed by permission of Covad Communications

Pavel Roskin <proski@gnu.org>

Lots of bugs fixes and patches.

Gyepi Sam <gyepi@praxis-sw.com>

Remote logging feature for syslogd

Linus Torvalds <torvalds@transmeta.com>

mkswap, fsck.minix, mkfs.minix

Mark Whitley <markw@codepoet.org>

grep, sed, cut, xargs(previous),
style-guide, new-applet-HOWTO, bug fixes, etc.

Charles P. Wright <cpwright@villagenet.com>

gzip, mini-netcat(nc)

Enrique Zanardi <ezanardi@ull.es>

tarcat (since removed), loadkmap, various fixes, Debian maintenance

Tito Ragusa <farmatito@tiscali.it>

devfsd and size optimizations in strings, openvt and deallocvt.

Paul Fox <pgf@foxharp.boston.ma.us>

vi editing mode for ash, various other patches/fixes

Roberto A. Foglietta <me@roberto.foglietta.name>

port: dnsd

Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

misc

Mike Frysinger <vapier@gentoo.org>

initial e2fsprogs, printenv, setarch, sum, misc

Jie Zhang <jie.zhang@analog.com>

fixed two bugs in msh and hush (exitcode of killed processes)