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:

        [, [[, addgroup, adduser, arp, arping, ash, awk, basename, bash,
        brctl, bunzip2, bzcat, bzip2, cat, chgrp, chmod, chown, chpasswd,
        chroot, clear, cp, crond, crontab, cut, date, dd, df, dhcp6c,
        dirname, dmesg, dnsdomainname, dos2unix, du, echo, egrep, eject,
        env, ether-wake, expr, false, fdisk, fgrep, find, flock, free,
        fuser, grep, gunzip, gzip, head, hostname, ifconfig, inetd, insmod,
        kill, killall, klogd, ln, logger, login, ls, lsmod, lsof, md5sum,
        mdev, microcom, mkdir, mknod, mkswap, modprobe, more, mount,
        mountpoint, mv, netstat, nice, nslookup, ntpd, passwd, pgrep, pidof,
        ping, ping6, printf, ps, pwd, rm, rmdir, rmmod, route, sed,
        sendmail, seq, sh, sleep, sort, start-stop-daemon, stat, strings,
        swapoff, swapon, switch_root, sync, sysctl, syslogd, tail, tar, tee,
        telnetd, test, time, top, touch, tr, traceroute, traceroute6, true,
        udhcpc, umount, uname, uniq, unix2dos, unlink, uptime, usleep,
        vconfig, vi, watch, wc, wget, which, whoami, xargs, yes, zcat, zcip

COMMAND DESCRIPTIONS

addgroup

addgroup [-g GID] [-S] [USER] GROUP

Add a group or add a user to a group

        -g GID  Group id
        -S      Create a system group
adduser

adduser [OPTIONS] USER [GROUP]

Create new user, or add USER to GROUP

        -h DIR          Home directory
        -g GECOS        GECOS field
        -s SHELL        Login shell
        -G GRP          Add user to existing group
        -S              Create a system user
        -D              Don't assign a password
        -H              Don't create home directory
        -u UID          User id
        -k SKEL         Skeleton directory (/etc/skel)
arp

arp [-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME] [-v] [-i IF] -d HOSTNAME [pub] [-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp] [-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub [-v] [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub

Manipulate ARP cache

        -a              Display (all) hosts
        -d              Delete ARP entry
        -s              Set new entry
        -v              Verbose
        -n              Don't resolve names
        -i IF           Network interface
        -D              Read HWADDR from IFACE
        -A,-p AF        Protocol family
        -H HWTYPE       Hardware address type
arping

arping [-fqbDUA] [-c CNT] [-w TIMEOUT] [-I IFACE] [-s SRC_IP] DST_IP

Send ARP requests/replies

        -f              Quit on first ARP reply
        -q              Quiet
        -b              Keep broadcasting, don't go unicast
        -D              Exit with 1 if DST_IP replies
        -U              Unsolicited ARP mode, update your neighbors
        -A              ARP answer mode, update your neighbors
        -c N            Stop after sending N ARP requests
        -w TIMEOUT      Seconds to wait for ARP reply
        -I IFACE        Interface to use (default br0)
        -s SRC_IP       Sender IP address
        DST_IP          Target IP address
ash

ash [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [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]

Strip directory path and .SUFFIX from FILE

bash

bash [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]

Unix shell interpreter

brctl

brctl COMMAND [BRIDGE [INTERFACE]]

Manage ethernet bridges

Commands:

        show                    Show a list of bridges
        addbr BRIDGE            Create BRIDGE
        delbr BRIDGE            Delete BRIDGE
        addif BRIDGE IFACE      Add IFACE to BRIDGE
        delif BRIDGE IFACE      Delete IFACE from BRIDGE
        setageing BRIDGE TIME           Set ageing time
        setfd BRIDGE TIME               Set bridge forward delay
        sethello BRIDGE TIME            Set hello time
        setmaxage BRIDGE TIME           Set max message age
        setpathcost BRIDGE COST         Set path cost
        setportprio BRIDGE PRIO         Set port priority
        setbridgeprio BRIDGE PRIO       Set bridge priority
        stp BRIDGE [1/yes/on|0/no/off]  STP on/off
bunzip2

bunzip2 [-cf] [FILE]...

Decompress FILEs (or stdin)

        -c      Write to stdout
        -f      Force
bzcat

bzcat [FILE]...

Decompress to stdout

bzip2

bzip2 [OPTIONS] [FILE]...

Compress FILEs (or stdin) with bzip2 algorithm

        -1..9   Compression level
        -d      Decompress
        -c      Write to stdout
        -f      Force
cat

cat [FILE]...

Concatenate FILEs and print them to stdout

chgrp

chgrp [-RhLHP]... GROUP FILE...

Change the group membership of each FILE to GROUP

        -R      Recurse
        -h      Affect symlinks instead of symlink targets
        -L      Traverse all symlinks to directories
        -H      Traverse symlinks on command line only
        -P      Don't traverse symlinks (default)
chmod

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

Each MODE is one or more of the letters ugoa, one of the symbols +-= and one or more of the letters rwxst

        -R      Recurse
chown

chown [-Rh]... OWNER[<.|:>[GROUP]] FILE...

Change the owner and/or group of each FILE to OWNER and/or GROUP

        -R      Recurse
        -h      Affect symlinks instead of symlink targets
chpasswd

chpasswd [--md5|--encrypted]

Read user:password from stdin and update /etc/passwd

        -e,--encrypted  Supplied passwords are in encrypted form
        -m,--md5        Use MD5 encryption instead of DES
chroot

chroot NEWROOT [PROG ARGS]

Run PROG with root directory set to NEWROOT

clear

clear

Clear screen

cp

cp [OPTIONS] SOURCE... DEST

Copy SOURCE(s) 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
        -l,-s   Create (sym)links
crond

crond -fbS -l N -d 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
        -d N    Set log level, log to stderr
        -L FILE Log to FILE
        -c DIR  Cron dir. Default:/etc/storage/cron/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 each input FILE to stdout

        -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
date

date [OPTIONS] [+FMT] [TIME]

Display time (using +FMT), or set time

        [-s,--set] TIME Set time to TIME
        -u,--utc        Work in UTC (don't convert to local time)
        -R,--rfc-2822   Output RFC-2822 compliant date string
        -I[SPEC]        Output ISO-8601 compliant date string
                        SPEC='date' (default) for date only,
                        'hours', 'minutes', or 'seconds' for date and
                        time to the indicated precision
        -r,--reference FILE     Display last modification time of FILE
        -d,--date TIME  Display TIME, not 'now'
        -D FMT          Use FMT for -d TIME conversion

Recognized TIME formats:

        hh:mm[:ss]
        [YYYY.]MM.DD-hh:mm[:ss]
        YYYY-MM-DD hh:mm[:ss]
        [[[[[YY]YY]MM]DD]hh]mm[.ss]
        'date TIME' form accepts MMDDhhmm[[YY]YY][.ss] instead
dd

dd [if=FILE] [of=FILE] [bs=N] [count=N] [skip=N] [seek=N]

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
        count=N         Copy only N input blocks
        skip=N          Skip N input blocks
        seek=N          Skip N output blocks
        status=noxfer   Suppress rate output
        status=none     Suppress all output

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

df

df [-PkmhTai] [-B SIZE] [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
        -a      Show all filesystems
        -i      Inodes
        -B SIZE Blocksize
dhcp6c

dhcp6c [-vfi] [-c FILE] [-D LL|LLT] [-p FILE] interface

        -v         Print debugging messages(may be repeated)
        -f         Foreground mode
        -i         Info-req(information-only) mode
        -c FILE    Use FILE as the configuration file
        -D LL|LLT  Use LL or LLT to override default(LLT) DUID type generation
        -p FILE    Use FILE to dump the process ID of dhcp6c
dirname

dirname FILENAME

Strip non-directory suffix from FILENAME

dmesg

dmesg [-c] [-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
dos2unix

dos2unix [-ud] [FILE]

Convert FILE in-place from DOS to Unix format. When no file is given, use stdin/stdout.

        -u      dos2unix
        -d      unix2dos
du

du [-aHLdclsxhmk] [FILE]...

Summarize disk space used for each FILE and/or directory

        -a      Show file sizes too
        -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 the specified ARGs to stdout

        -n      Suppress trailing newline
        -e      Interpret backslash escapes (i.e., \t=tab)
        -E      Don't interpret backslash escapes (default)
eject

eject [-t] [-T] [DEVICE]

Eject DEVICE or default /dev/cdrom

        -s      SCSI device
        -t      Close tray
        -T      Open/close tray (toggle)
env

env [-iu] [-] [name=value]... [PROG ARGS]

Print the current environment or run PROG after setting up the specified environment

        -, -i   Start with an empty environment
        -u      Remove variable from the environment
ether-wake

ether-wake [-b] [-i IFACE] [-p aa:bb:cc:dd[:ee:ff]/a.b.c.d] MAC

Send a magic packet to wake up sleeping machines. MAC must be a station address (00:11:22:33:44:55) or a hostname with a known 'ethers' entry.

        -b              Broadcast the packet
        -i IFACE        Interface to use (default eth0)
        -p PASSWORD     Append four or six byte PASSWORD to the packet
expr

expr EXPRESSION

Print the value of EXPRESSION to stdout

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 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.

fdisk

fdisk [-ul] [-C CYLINDERS] [-H HEADS] [-S SECTORS] [-b SSZ] DISK

Change partition table

        -u              Start and End are in sectors (instead of cylinders)
        -l              Show partition table for each DISK, then exit
        -b 2048         (for certain MO disks) use 2048-byte sectors
        -C CYLINDERS    Set number of cylinders/heads/sectors
        -H HEADS
        -S SECTORS
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,...)
        -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
        -inum N         File has inode number N
        -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
        -links N        Number of links is greater than (+N), less than (-N),
                        or exactly 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
        -exec CMD ARG + Run CMD with {} replaced by list of file names
        -delete         Delete current file/directory. Turns on -depth option
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 the amount of free and used system memory

fuser

fuser [OPTIONS] FILE or PORT/PROTO

Find processes which use FILEs or PORTs

        -m      Find processes which use same fs as FILEs
        -4,-6   Search only IPv4/IPv6 space
        -s      Don't display PIDs
        -k      Kill found processes
        -SIGNAL Signal to send (default: KILL)
grep

grep [-HhnlLoqvsriwFE] [-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
        -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 [-cft] [FILE]...

Decompress FILEs (or stdin)

        -c      Write to stdout
        -f      Force
        -t      Test file integrity
gzip

gzip [-cfd] [FILE]...

Compress FILEs (or stdin)

        -d      Decompress
        -c      Write to stdout
        -f      Force

head [OPTIONS] [FILE]...

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

        -n N[kbm]       Print first N lines
        -n -N[kbm]      Print all except N last lines
        -c [-]N[kbm]    Print first N bytes
        -q              Never print headers
        -v              Always print headers

N may be suffixed by k (x1024), b (x512), or m (x1024^2).

hostname

hostname [OPTIONS] [HOSTNAME | -F FILE]

Get or set hostname or DNS domain name

        -s      Short
        -i      Addresses for the hostname
        -d      DNS domain name
        -f      Fully qualified domain name
        -F FILE Use FILE's content as hostname
ifconfig

ifconfig [-a] interface [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]
        [mem_start NN] [io_addr NN] [irq NN]
        [up|down] ...
inetd

inetd [-fe] [-q N] [-R N] [CONFFILE]

Listen for network connections and launch programs

        -f      Run in foreground
        -e      Log to stderr
        -q N    Socket listen queue (default: 128)
        -R N    Pause services after N connects/min
                (default: 0 - disabled)
insmod

insmod FILE [SYMBOL=VALUE]...

Load kernel module

kill

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

Send a signal (default: TERM) to given PIDs

        -l      List all signal names and numbers
killall

killall [-l] [-q] [-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
klogd

klogd [-c N] [-n]

Kernel logger

        -c N    Print to console messages more urgent than prio N (1-8)
        -n      Run in foreground
ln

ln [OPTIONS] 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      2nd arg must be a DIR
        -v      Verbose
logger

logger [OPTIONS] [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 (numeric 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      Name of the remote host
        -p      Preserve environment
ls

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

List directory contents

        -1      One column output
        -a      Include entries which start with .
        -A      Like -a, but exclude . and ..
        -C      List by columns
        -x      List by lines
        -d      List directory entries instead of contents
        -L      Follow symlinks
        -H      Follow symlinks on command line
        -R      Recurse
        -p      Append / to dir entries
        -F      Append indicator (one of */=@|) to entries
        -l      Long listing format
        -i      List inode numbers
        -n      List numeric UIDs and GIDs instead of names
        -s      List allocated blocks
        -e      List full date and time
        -h      List sizes in human readable format (1K 243M 2G)
        -r      Sort in reverse order
        -S      Sort by size
        -X      Sort by extension
        -v      Sort by version
        -c      With -l: sort by ctime
        -t      With -l: sort by mtime
        -u      With -l: sort by atime
        -w N    Assume the terminal is N columns wide
        --color[={always,never,auto}]   Control coloring
lsmod

lsmod

List the currently loaded kernel modules

lsof

lsof

Show all open files

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
mdev

mdev [-s]

mdev -s is to be run during boot to scan /sys and populate /dev.

Bare mdev is a kernel hotplug helper. To activate it: echo /sbin/mdev >/proc/sys/kernel/hotplug

It uses /etc/mdev.conf with lines [-][ENV=regex;]...DEVNAME UID:GID PERM [@|$|*PROG] where DEVNAME is device name regex, @major,minor[-minor2], or environment variable regex. A common use of the latter is to load modules for hotplugged devices:

        $MODALIAS=.* 0:0 660 @modprobe "$MODALIAS"

If /dev/mdev.seq file exists, mdev will wait for its value to match $SEQNUM variable. This prevents plug/unplug races. To activate this feature, create empty /dev/mdev.seq at boot.

If /dev/mdev.log file exists, debug log will be appended to it.

microcom

microcom [-d DELAY] [-t TIMEOUT] [-s SPEED] [-X] TTY

Copy bytes for stdin to TTY and from TTY to stdout

        -d      Wait up to DELAY ms for TTY output before sending every
                next byte to it
        -t      Exit if both stdin and TTY are silent for TIMEOUT ms
        -s      Set serial line to SPEED
        -X      Disable special meaning of NUL and Ctrl-X from stdin
mkdir

mkdir [OPTIONS] DIRECTORY...

Create DIRECTORY

        -m MODE Mode
        -p      No error if exists; make parent directories as needed
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 and MINOR are ignored)
mkswap

mkswap [-L LBL] BLOCKDEV [KBYTES]

Prepare BLOCKDEV to be used as swap partition

        -L LBL  Label
modprobe

modprobe [-alrqvsD] MODULE [SYMBOL=VALUE]...

        -a      Load multiple MODULEs
        -l      List (MODULE is a pattern)
        -r      Remove MODULE (stacks) or do autoclean
        -q      Quiet
        -v      Verbose
        -s      Log to syslog
        -D      Show dependencies
more

more [FILE]...

View FILE (or stdin) one screenful at a time

mount

mount [OPTIONS] [-o OPT] DEVICE NODE

Mount a filesystem. Filesystem autodetection requires /proc.

        -a              Mount all filesystems in fstab
        -f              Dry run
        -v              Verbose
        -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.

mountpoint

mountpoint [-q] <[-dn] DIR | -x DEVICE>

Check if the directory is a mountpoint

        -q      Quiet
        -d      Print major/minor device number of the filesystem
        -n      Print device name of the filesystem
        -x      Print major/minor device number of the blockdevice
mv

mv [-fin] SOURCE DEST or: mv [-fin] SOURCE... DIRECTORY

Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY

        -f      Don't prompt before overwriting
        -i      Interactive, prompt before overwrite
        -n      Don't overwrite an existing file
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 [HOST] [SERVER]

Query the nameserver for the IP address of the given HOST optionally using a specified DNS server

ntpd

ntpd [-dnqNwt] [-S PROG] [-p PEER]...

NTP client/server

        -d      Verbose
        -n      Do not daemonize
        -q      Quit after clock is set
        -N      Run at high priority
        -w      Do not set time (only query peers), implies -n
        -t      Trust network and server, no RFC-4330 cross-checks
        -S PROG Run PROG after stepping time, stratum change, and every 11 mins
        -p PEER Obtain time from PEER (may be repeated)
passwd

passwd [OPTIONS] [USER]

Change USER's password (default: current user)

        -a ALG  Encryption method
        -d      Set password to ''
        -l      Lock (disable) account
        -u      Unlock (enable) account
pgrep

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

Display process(es) selected by regex PATTERN

        -l      Show command name 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 [OPTIONS] [NAME]...

List PIDs of all processes with names that match NAMEs

        -s      Show only one PID
        -o PID  Omit given pid
                Use %PPID to omit pid of pidof's parent
ping

ping [OPTIONS] HOST

Send ICMP ECHO_REQUEST packets to network hosts

        -4,-6           Force IP or IPv6 name resolution
        -c CNT          Send only CNT pings
        -s SIZE         Send SIZE data bytes in packets (default:56)
        -t TTL          Set TTL
        -I IFACE/IP     Use interface or IP address as source
        -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
                        and when finished
        -p              Pattern to use for payload
ping6

ping6 [OPTIONS] HOST

Send ICMP ECHO_REQUEST packets to network hosts

        -c CNT          Send only CNT pings
        -s SIZE         Send SIZE data bytes in packets (default:56)
        -I IFACE/IP     Use interface or IP address as source
        -q              Quiet, only display output at start
                        and when finished
        -p              Pattern to use for payload
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
        l       Long output
        T       Show threads
pwd

pwd

Print the full filename of the current working directory

rm

rm [-irf] FILE...

Remove (unlink) FILEs

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

rmdir [OPTIONS] DIRECTORY...

Remove DIRECTORY if it is empty

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

rmmod [-wfa] [MODULE]...

Unload kernel modules

        -w      Wait until the module is no longer used
        -f      Force unload
        -a      Remove all unused modules (recursively)
route

route [{add|del|delete}]

Edit kernel routing tables

        -n      Don't resolve names
        -e      Display other/more information
        -A inet{6}      Select address family
sed

sed [-inrE] [-f FILE]... [-e CMD]... [FILE]... or: sed [-inrE] 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 sends 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).

sendmail

sendmail [OPTIONS] [RECIPIENT_EMAIL]...

Read email from stdin and send it

Standard options:

        -t              Read additional recipients from message body
        -f SENDER       For use in MAIL FROM:<sender>. Can be empty string
                        Default: -auUSER, or username of current UID
        -o OPTIONS      Various options. -oi implied, others are ignored
        -i              -oi synonym. implied and ignored

Busybox specific options:

        -v              Verbose
        -w SECS         Network timeout
        -H 'PROG ARGS'  Run connection helper
                        Examples:
                        -H 'exec openssl s_client -quiet -tls1 -starttls smtp
                                -connect smtp.gmail.com:25' <email.txt
                                [4<username_and_passwd.txt | -auUSER -apPASS]
                        -H 'exec openssl s_client -quiet -tls1
                                -connect smtp.gmail.com:465' <email.txt
                                [4<username_and_passwd.txt | -auUSER -apPASS]
        -S HOST[:PORT]  Server
        -auUSER         Username for AUTH LOGIN
        -apPASS         Password for AUTH LOGIN

Other options are silently ignored; -oi -t is implied

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 [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]

Unix shell interpreter

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
        -u      Suppress duplicate lines
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
                        command in /proc/PID/cmdline
        -p FILE         Match a process with PID from the file
        All specified conditions must match
-S only:
        -x EXECUTABLE   Program to run
        -a NAME         Zeroth argument
        -b              Background
        -N N            Change nice level
        -c USER[:[GRP]] Change to user/group
        -m              Write PID to the pidfile specified by -p
-K only:
        -s SIG          Signal to send
        -t              Match only, exit with 0 if a process is found
Other:

        -o              Exit with status 0 if nothing is done
        -v              Verbose
        -q              Quiet
stat

stat [OPTIONS] FILE...

Display file (default) or filesystem status

        -c fmt  Use the specified format
        -f      Display filesystem status
        -L      Follow links
        -t      Display info in terse form

Valid format sequences for files:

 %a     Access rights in octal
 %A     Access rights in human readable form
 %b     Number of blocks allocated (see %B)
 %B     The size in bytes of each block reported by %b
 %d     Device number in decimal
 %D     Device number in hex
 %f     Raw mode in hex
 %F     File type
 %g     Group ID of owner
 %G     Group name of owner
 %h     Number of hard links
 %i     Inode number
 %n     File name
 %N     File name, with -> TARGET if symlink
 %o     I/O block size
 %s     Total size, in bytes
 %t     Major device type in hex
 %T     Minor device type in hex
 %u     User ID of owner
 %U     User name of owner
 %x     Time of last access
 %X     Time of last access as seconds since Epoch
 %y     Time of last modification
 %Y     Time of last modification as seconds since Epoch
 %z     Time of last change
 %Z     Time of last change as seconds since Epoch

Valid format sequences for file systems:

 %a     Free blocks available to non-superuser
 %b     Total data blocks in file system
 %c     Total file nodes in file system
 %d     Free file nodes in file system
 %f     Free blocks in file system
 %i     File System ID in hex
 %l     Maximum length of filenames
 %n     File name
 %s     Block size (for faster transfer)
 %S     Fundamental block size (for block counts)
 %t     Type in hex
 %T     Type in human readable form
strings

strings [-afo] [-n LEN] [FILE]...

Display printable strings in a binary file

        -a      Scan whole file (default)
        -f      Precede strings with filenames
        -n LEN  At least LEN characters form a string (default 4)
        -o      Precede strings with decimal offsets
swapoff

swapoff [-a] [-e] [DEVICE]

Stop swapping on DEVICE

        -a      Stop swapping on all swap devices
        -e      Silently skip devices that do not exist
swapon

swapon [-a] [-e] [-d[POL]] [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
switch_root

switch_root [-c /dev/console] 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 [OPTIONS] [KEY[=VALUE]]...

Show/set kernel parameters

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

syslogd [OPTIONS]

System logging utility (this version of syslogd ignores /etc/syslog.conf)

        -n              Run in foreground
        -R HOST[:PORT]  Log to HOST:PORT (default PORT:514)
        -L              Log locally and via network (default is network only if -R)
        -C[size_kb]     Log to shared mem buffer (use logread to read it)
        -O FILE         Log to FILE (default:/var/log/messages, stdout if -)
        -s SIZE         Max size (KB) before rotation (default:200KB, 0=off)
        -b N            N rotated logs to keep (default:1, max=99, 0=purge)
        -l N            Log only messages more urgent than prio N (1-8)
        -S              Smaller output
        -D              Drop duplicates
tail

tail [OPTIONS] [FILE]...

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

        -f              Print data as file grows
        -c [+]N[kbm]    Print last N bytes
        -n N[kbm]       Print last N lines
        -n +N[kbm]      Start on Nth line and print the rest
        -q              Never print headers
        -s SECONDS      Wait SECONDS between reads with -f
        -v              Always print headers
        -F              Same as -f, but keep retrying

N may be suffixed by k (x1024), b (x512), or m (x1024^2).

tar

tar -[cxtzjhvO] [-X FILE] [-T FILE] [-f TARFILE] [-C DIR] [FILE]...

Create, extract, or list files from a tar file

Operation:

        c       Create
        x       Extract
        t       List
        f       Name of TARFILE ('-' for stdin/out)
        C       Change to DIR before operation
        v       Verbose
        z       (De)compress using gzip
        j       (De)compress using bzip2
        O       Extract to stdout
        h       Follow symlinks
        X       File with names to exclude
        T       File with names to include
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)
telnetd

telnetd [OPTIONS]

Handle incoming telnet connections

        -l LOGIN        Exec LOGIN on connect
        -f ISSUE_FILE   Display ISSUE_FILE instead of /etc/issue
        -K              Close connection as soon as login exits
                        (normally wait until all programs close slave pty)
        -p PORT         Port to listen on
        -b ADDR[:PORT]  Address to bind to
        -F              Run in foreground
        -i              Inetd mode
time

time [-v] PROG ARGS

Run PROG, display resource usage when it exits

        -v      Verbose
top

top [-b] [-nCOUNT] [-dSECONDS] [-m]

Provide a view of process activity in real time. Read the status of all processes from /proc each SECONDS and display a screenful of them. Keys:

        N/M/P/T: show CPU usage, sort by pid/mem/cpu/time
        S: show memory
        R: reverse sort
        H: toggle threads
        Q,^C: exit

Options:

        -b      Batch mode
        -n N    Exit after N iterations
        -d N    Delay between updates
        -m      Same as 's' key
touch

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

Update the last-modified date on the given FILE[s]

        -c      Don't create files
        -h      Don't follow links
        -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 [-46FIlnrv] [-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
        -I      Use ICMP ECHO instead of UDP datagrams
        -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  Time to wait for a response (default 3)
        -g IP   Loose source route gateway (8 max)
traceroute6

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

Trace the route to HOST

        -n      Print numeric addresses
        -r      Bypass routing tables, send directly to HOST
        -v      Verbose
        -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  Time wait for a response (default 3)
udhcpc

udhcpc [-fbqvRB] [-a[MSEC]] [-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,--interface IFACE    Interface to use (default eth0)
        -s,--script PROG        Run PROG at DHCP events (default /tmp/udhcpc.script)
        -p,--pidfile FILE       Create pidfile
        -B,--broadcast          Request broadcast replies
        -t,--retries N          Send up to N discover packets (default 3)
        -T,--timeout SEC        Pause between packets (default 3)
        -A,--tryagain SEC       Wait if lease is not obtained (default 20)
        -n,--now                Exit if lease is not obtained
        -q,--quit               Exit after obtaining lease
        -R,--release            Release IP on exit
        -f,--foreground         Run in foreground
        -b,--background         Background if lease is not obtained
        -d,--daemon             Background after run
        -S,--syslog             Log to syslog too
        -a[MSEC],--arping[=MSEC] Validate offered address with ARP ping
        -r,--request IP         Request this IP address
        -o,--no-default-options Don't request any options (unless -O is given)
        -O,--request-option 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)
        -F,--fqdn NAME          Ask server to update DNS mapping for NAME
        -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')
        -C,--clientid-none      Don't send MAC as client identifier
        -v                      Verbose
Signals:

        USR1    Renew lease
        USR2    Release lease
umount

umount [OPTIONS] FILESYSTEM|DIRECTORY

Unmount file systems

        -r      Try to remount devices as read-only if mount is busy
        -l      Lazy umount (detach filesystem)
        -f      Force umount (i.e., unreachable NFS server)
        -D      Don't free loop device even if it has been used
uname

uname [-amnrspvio]

Print system information

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

uniq [-cdu][-f,s,w N] [INPUT [OUTPUT]]

Discard duplicate lines

        -c      Prefix lines by the number of occurrences
        -d      Only print duplicate lines
        -u      Only print unique lines
        -f N    Skip first N fields
        -s N    Skip first N chars (after any skipped fields)
        -w N    Compare N characters in line
unix2dos

unix2dos [-ud] [FILE]

Convert FILE in-place from Unix to DOS format. When no file is given, use stdin/stdout.

        -u      dos2unix
        -d      unix2dos

unlink FILE

Delete FILE by calling unlink()

uptime

uptime

Display the time since the last boot

usleep

usleep N

Pause for N microseconds

vconfig

vconfig COMMAND [OPTIONS]

Create and remove virtual ethernet devices

        add             IFACE VLAN_ID
        rem             VLAN_NAME
        set_flag        IFACE 0|1 VLAN_QOS
        set_egress_map  VLAN_NAME SKB_PRIO VLAN_QOS
        set_ingress_map VLAN_NAME SKB_PRIO VLAN_QOS
        set_name_type   NAME_TYPE
vi

vi [OPTIONS] [FILE]...

Edit FILE

        -c CMD  Initial command to run ($EXINIT also available)
        -R      Read-only
        -H      List available features
watch

watch [-n SEC] [-t] PROG ARGS

Run PROG periodically

        -n      Loop period in seconds (default 2)
        -t      Don't print header
wc

wc [-cmlwL] [FILE]...

Count lines, words, and bytes for each FILE (or stdin)

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

wget [-c|--continue] [-s|--spider] [-q|--quiet] [-O|--output-document FILE] [--header 'header: value'] [-Y|--proxy on/off] [-P DIR] [-U|--user-agent AGENT] [-T SEC] URL...

Retrieve files via HTTP or FTP

        -s      Spider mode - only check file existence
        -c      Continue retrieval of aborted transfer
        -q      Quiet
        -P DIR  Save to DIR (default .)
        -T SEC  Network read timeout is SEC seconds
        -O FILE Save to FILE ('-' for stdout)
        -U STR  Use STR for User-Agent header
        -Y      Use proxy ('on' or 'off')
which

which [COMMAND]...

Locate a COMMAND

whoami

whoami

Print the user name associated with the current effective user id

xargs

xargs [OPTIONS] [PROG ARGS]

Run PROG on every item given by stdin

        -p      Ask user whether to run each command
        -r      Don't run command if input is empty
        -0      Input is separated by NUL characters
        -t      Print the command on stderr before execution
        -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
        -I STR  Replace STR within PROG ARGS with input line
        -x      Exit if size is exceeded
yes

yes [STRING]

Repeatedly output a line with STRING, or 'y'

zcat

zcat [FILE]...

Decompress to stdout

zcip

zcip [OPTIONS] IFACE SCRIPT

Manage a ZeroConf IPv4 link-local address

        -f              Run in foreground
        -q              Quit after obtaining address
        -r 169.254.x.x  Request this address first
        -l x.x.0.0      Use this range instead of 169.254
        -v              Verbose

$LOGGING=none Suppress logging $LOGGING=syslog Log to syslog

With no -q, runs continuously monitoring for ARP conflicts, exits only on I/O errors (link down etc)

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 <[email protected]>

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 <[email protected]> run-parts


Erik Andersen <[email protected]>

    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 <[email protected]>

    rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm

Jeff Angielski <[email protected]>

    ftpput, ftpget

Edward Betts <[email protected]>

    expr, hostid, logname, whoami

John Beppu <[email protected]>

    du, nslookup, sort

Brian Candler <[email protected]>

    tiny-ls(ls)

Randolph Chung <[email protected]>

    fbset, ping, hostname

Dave Cinege <[email protected]>

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

Jordan Crouse <[email protected]>

    ipcalc

Magnus Damm <[email protected]>

    tftp client insmod powerpc support

Larry Doolittle <[email protected]>

    pristine source directory compilation, lots of patches and fixes.

Glenn Engel <[email protected]>

    httpd

Gennady Feldman <[email protected]>

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

Karl M. Hegbloom <[email protected]>

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

Daniel Jacobowitz <[email protected]>

    mktemp.c

Matt Kraai <[email protected]>

    documentation, bugfixes, test suite

Stephan Linz <[email protected]>

    ipcalc, Red Hat equivalence

John Lombardo <[email protected]>

    tr

Glenn McGrath <[email protected]>

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

Manuel Novoa III <[email protected]>

    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 <[email protected]>

    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 <[email protected]>

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

Tim Riker <[email protected]>

    bug fixes, member of fan club

Kent Robotti <[email protected]>

    reset, tons and tons of bug reports and patches.

Chip Rosenthal <[email protected]>, <[email protected]>

    wget - Contributed by permission of Covad Communications

Pavel Roskin <[email protected]>

    Lots of bugs fixes and patches.

Gyepi Sam <[email protected]>

    Remote logging feature for syslogd

Linus Torvalds <[email protected]>

    mkswap, fsck.minix, mkfs.minix

Mark Whitley <[email protected]>

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

Charles P. Wright <[email protected]>

    gzip, mini-netcat(nc)

Enrique Zanardi <[email protected]>

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

Tito Ragusa <[email protected]>

    devfsd and size optimizations in strings, openvt and deallocvt.

Paul Fox <[email protected]>

    vi editing mode for ash, various other patches/fixes

Roberto A. Foglietta <[email protected]>

    port: dnsd

Bernhard Reutner-Fischer <[email protected]>

    misc

Mike Frysinger <[email protected]>

    initial e2fsprogs, printenv, setarch, sum, misc

Jie Zhang <[email protected]>

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