BusyBox - The Swiss Army Knife of Embedded Linux


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


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.


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.


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.


Currently available applets include:

[, [[, adjtimex, arping, ash, awk, basename, blockdev, brctl, bunzip2, bzcat, bzip2, cal, cat, chgrp, chmod, chown, chroot, chvt, clear, cmp, cp, cpio, cut, date, dc, dd, deallocvt, df, dirname, dmesg, dnsdomainname, dos2unix, du, dumpkmap, dumpleases, echo, egrep, env, expr, false, fgrep, find, fold, free, ftpget, ftpput, getopt, grep, gunzip, gzip, head, hexdump, hostid, hostname, httpd, id, ifconfig, ionice, ip, ipcalc, kill, killall, klogd, last, length, ln, loadfont, loadkmap, logger, logname, logread, losetup, ls, lzcat, lzma, md5sum, mkdir, mkfifo, mknod, mktemp, more, mount, mt, mv, nameif, nc, netstat, nslookup, od, openvt, patch, pidof, ping, ping6, printf, ps, pwd, rdate, readlink, realpath, renice, reset, rev, rm, rmdir, route, rpm, rpm2cpio, run-parts, sed, setkeycodes, sh, sha1sum, sha256sum, sha512sum, sleep, sort, start-stop-daemon, strings, stty, swapoff, swapon, sync, sysctl, syslogd, tac, tail, tar, tee, telnet, test, tftp, time, top, touch, tr, traceroute, traceroute6, true, tty, udhcpc, udhcpd, umount, uname, uncompress, uniq, unix2dos, unlzma, unxz, unzip, uptime, usleep, uudecode, uuencode, vi, watch, watchdog, wc, wget, which, who, whoami, xargs, xz, xzcat, yes, zcat


adjtimex 4 adjtimex [-q] [-o OFF] [-f FREQ] [-p TCONST] [-t TICK] .Sp Read and optionally set system timebase parameters. See adjtimex (2) .Sp Options: .Sp -q Quiet -o OFF Time offset, microseconds -f FREQ Frequency adjust, integer kernel units (65536 is 1ppm) (positive values make clock run faster) -t TICK Microseconds per tick, usually 10000 -p TCONST

arping 4 arping [-fqbDUA] [-c CNT] [-w TIMEOUT] [-I IFACE] [-s SRC_IP] DST_IP .Sp Send ARP requests/replies .Sp Options: .Sp -f Quit on first ARP reply -q Quiet -b Keep broadcasting, don\*(Aqt go unicast -D Duplicated address detection mode -U Unsolicited ARP mode, update your neighbors -A ARP answer mode, update your neighbors -c N Stop after sending N ARP requests -w TIMEOUT Time to wait for ARP reply, seconds -I IFACE Interface to use (default eth0) -s SRC_IP Sender IP address DST_IP Target IP address

awk 4 awk [OPTIONS] [AWK_PROGRAM] [FILE]... .Sp Options: .Sp -v VAR=VAL Set variable -F SEP Use SEP as field separator -f FILE Read program from FILE

basename 4 basename FILE [SUFFIX] .Sp Strip directory path and .SUFFIX from FILE

blockdev 4 blockdev OPTION BLOCKDEV .Sp Options: .Sp --setro Set ro --setrw Set rw --getro Get ro --getss Get sector size --getbsz Get block size --setbsz BYTES Set block size --getsize Get device size in 512-byte sectors --getsize64 Get device size in bytes --flushbufs Flush buffers --rereadpt Reread partition table

brctl 4 brctl COMMAND [BRIDGE [INTERFACE]] .Sp Manage ethernet bridges .Sp Commands: .Sp addbr BRIDGE Create BRIDGE delbr BRIDGE Delete BRIDGE addif BRIDGE IFACE Add IFACE to BRIDGE delif BRIDGE IFACE Delete IFACE from BRIDGE

bunzip2 4 bunzip2 [OPTIONS] [FILE]... .Sp Decompress FILEs (or stdin) .Sp Options: .Sp -c Write to stdout -f Force

bzcat 4 bzcat FILE .Sp Decompress to stdout

bzip2 4 bzip2 [OPTIONS] [FILE]... .Sp Compress FILEs (or stdin) with bzip2 algorithm .Sp Options: .Sp -1..9 Compression level -d Decompress -c Write to stdout -f Force

cal 4 cal [-jy] [[MONTH] YEAR] .Sp Display a calendar .Sp Options: .Sp -j Use julian dates -y Display the entire year

cat 4 cat [FILE]... .Sp Concatenate FILEs and print them to stdout

chgrp 4 chgrp [-RhLHPcvf]... GROUP FILE... .Sp Change the group membership of each FILE to GROUP .Sp Options: .Sp -R Recurse -h Affect symlinks instead of symlink targets -L Traverse all symlinks to directories -H Traverse symlinks on command line only -P Don\*(Aqt traverse symlinks (default) -c List changed files -v Verbose -f Hide errors

chmod 4 chmod [-Rcvf] MODE[,MODE]... FILE... .Sp Each MODE is one or more of the letters ugoa, one of the symbols +-= and one or more of the letters rwxst .Sp Options: .Sp -R Recurse -c List changed files -v List all files -f Hide errors

chown 4 chown [-RhLHPcvf]... OWNER[<.|:>[GROUP]] FILE... .Sp Change the owner and/or group of each FILE to OWNER and/or GROUP .Sp Options: .Sp -R Recurse -h Affect symlinks instead of symlink targets -L Traverse all symlinks to directories -H Traverse symlinks on command line only -P Don\*(Aqt traverse symlinks (default) -c List changed files -v List all files -f Hide errors

chroot 4 chroot NEWROOT [PROG ARGS] .Sp Run PROG with root directory set to NEWROOT

chvt 4 chvt N .Sp Change the foreground virtual terminal to /dev/ttyN

clear 4 clear .Sp Clear screen

cmp 4 cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]] .Sp Compare FILE1 with FILE2 (or stdin) .Sp Options: .Sp -l Write the byte numbers (decimal) and values (octal) for all differing bytes -s Quiet

cp 4 cp [OPTIONS] SOURCE DEST .Sp Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY .Sp Options: .Sp -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

cpio 4 cpio [-dmvu] [-F FILE] [-H newc] [-tio] .Sp Extract or list files from a cpio archive, or create an archive using file list on stdin .Sp Main operation mode: .Sp -t List -i Extract -o Create (requires -H newc) Options: -d Make leading directories -m Preserve mtime -v Verbose -u Overwrite -F FILE Input (-t,-i,-p) or output (-o) file -H newc Archive format

cut 4 cut [OPTIONS] [FILE]... .Sp Print selected fields from each input FILE to stdout .Sp Options: .Sp -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 4 date [OPTIONS] [+FMT] [TIME] .Sp Display time (using +FMT), or set time .Sp Options: .Sp [-s,--set] TIME Set time to TIME -u,--utc Work in UTC (don\*(Aqt convert to local time) -R,--rfc-2822 Output RFC-2822 compliant date string -I[SPEC] Output ISO-8601 compliant date string SPEC=\*(Aqdate\*(Aq (default) for date only, \*(Aqhours\*(Aq, \*(Aqminutes\*(Aq, or \*(Aqseconds\*(Aq for date and time to the indicated precision -r,--reference FILE Display last modification time of FILE -d,--date TIME Display TIME, not \*(Aqnow\*(Aq -D FMT Use FMT for -d TIME conversion

.Sp Recognized TIME formats: .Sp hh:mm[:ss] [YYYY.]MM.DD-hh:mm[:ss] YYYY-MM-DD hh:mm[:ss] [[[[[YY]YY]MM]DD]hh]mm[.ss]

dc 4 dc expression... .Sp Tiny RPN calculator. Operations: +, add, -, sub, *, mul, /, div, %, mod, **, exp, and, or, not, eor, p - print top of the stack (without altering the stack), f - print entire stack, o - pop the value and set output radix (value must be 10 or 16). Examples: 'dc 2 2 add' -> 4, 'dc 8 8 * 2 2 + /' -> 16

dd 4 dd [if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N] [skip=N] [seek=N] [conv=notrunc|noerror|sync|fsync] .Sp Copy a file with converting and formatting .Sp Options: .Sp 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\*(Aqt truncate output file conv=noerror Continue after read errors conv=sync Pad blocks with zeros conv=fsync Physically write data out before finishing

.Sp Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024), MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)

deallocvt 4 deallocvt [N] .Sp Deallocate unused virtual terminal /dev/ttyN

df 4 df [-Pkmhai] [-B SIZE] [FILESYSTEM]... .Sp Print filesystem usage statistics .Sp Options: .Sp -P POSIX output format -k 1024-byte blocks (default) -m 1M-byte blocks -h Human readable (e.g. 1K 243M 2G) -a Show all filesystems -i Inodes -B SIZE Blocksize

dirname 4 dirname FILENAME .Sp Strip non-directory suffix from FILENAME

dmesg 4 dmesg [-c] [-n LEVEL] [-s SIZE] .Sp Print or control the kernel ring buffer .Sp Options: .Sp -c Clear ring buffer after printing -n LEVEL Set console logging level -s SIZE Buffer size

dos2unix 4 dos2unix [OPTIONS] [FILE] .Sp Convert FILE in-place from DOS to Unix format. When no file is given, use stdin/stdout. .Sp Options: .Sp -u dos2unix -d unix2dos

du 4 du [-aHLdclsxhmk] [FILE]... .Sp Summarize disk space used for each FILE and/or directory. Disk space is printed in units of 1024 bytes. .Sp Options: .Sp -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)

dumpkmap 4 dumpkmap > keymap .Sp Print a binary keyboard translation table to stdout

dumpleases 4 dumpleases [-r|-a] [-f LEASEFILE] .Sp Display DHCP leases granted by udhcpd .Sp Options: .Sp -f,--file=FILE Lease file -r,--remaining Show remaining time -a,--absolute Show expiration time

echo 4 echo [-neE] [ARG]... .Sp Print the specified ARGs to stdout .Sp Options: .Sp -n Suppress trailing newline -e Interpret backslash escapes (i.e., \t=tab) -E Don\*(Aqt interpret backslash escapes (default)

env 4 env [-iu] [-] [name=value]... [PROG ARGS] .Sp Print the current environment or run PROG after setting up the specified environment .Sp Options: .Sp -, -i Start with an empty environment -u Remove variable from the environment

expr 4 expr EXPRESSION .Sp Print the value of EXPRESSION to stdout .Sp EXPRESSION may be: .Sp 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 \*(Aqmatch\*(Aq or an operator like \*(Aq/\*(Aq (EXPRESSION) Value of EXPRESSION

.Sp Beware that many operators need to be escaped or quoted for shells. Comparisons are arithmetic if both ARGs are numbers, else lexicographical. Pattern matches return the string matched between \( and \) or null; if \( and \) are not used, they return the number of characters matched or 0.

false 4 false .Sp Return an exit code of FALSE (1)

find 4 find [PATH]... [EXPRESSION] .Sp Search for files. The default PATH is the current directory, default EXPRESSION is '-print' .Sp EXPRESSION may consist of: .Sp -follow Follow symlinks -xdev Don\*(Aqt descend directories on other filesystems -maxdepth N Descend at most N levels. -maxdepth 0 applies tests/actions to command line arguments only -mindepth N Don\*(Aqt act on first N levels -name PATTERN File name (w/o directory name) matches PATTERN -iname PATTERN Case insensitive -name -path PATTERN Path matches PATTERN -regex PATTERN Path matches regex PATTERN -type X File type is X (X is one of: f,d,l,b,c,...) -perm NNN Permissions match any of (+NNN), all of (-NNN), or exactly NNN -mtime DAYS Modified time is greater than (+N), less than (-N), or exactly N days -mmin MINS Modified time is greater than (+N), less than (-N), or exactly N minutes -newer FILE Modified time is more recent than FILE\*(Aqs -inum N File has inode number N -user NAME File is owned by user NAME (numeric user ID allowed) -group NAME File belongs to group NAME (numeric group ID allowed) -depth Process directory name after traversing it -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 -print Print (default and assumed) -print0 Delimit output with null characters rather than newlines -exec CMD ARG ; Run CMD with all instances of {} replaced by the matching files -prune Stop traversing current subtree (EXPR) Group an expression

fold 4 fold [-bs] [-w WIDTH] [FILE]... .Sp Wrap input lines in each FILE (or stdin), writing to stdout .Sp Options: .Sp -b Count bytes rather than columns -s Break at spaces -w Use WIDTH columns instead of 80

free 4 free .Sp Display the amount of free and used system memory

ftpget 4 ftpget [OPTIONS] HOST [LOCAL_FILE] REMOTE_FILE .Sp Retrieve a remote file via FTP .Sp Options: .Sp -c,--continue Continue previous transfer -v,--verbose Verbose -u,--username Username -p,--password Password -P,--port Port number

ftpput 4 ftpput [OPTIONS] HOST [REMOTE_FILE] LOCAL_FILE .Sp Store a local file on a remote machine via FTP .Sp Options: .Sp -v,--verbose Verbose -u,--username Username -p,--password Password -P,--port Port number

getopt 4 getopt [OPTIONS] .Sp Options: .Sp -a,--alternative Allow long options starting with single - -l,--longoptions=longopts Long options to be recognized -n,--name=progname The name under which errors are reported -o,--options=optstring Short options to be recognized -q,--quiet Disable error reporting by getopt(3) -Q,--quiet-output No normal output -s,--shell=shell Set shell quoting conventions -T,--test Test for getopt(1) version -u,--unquoted Don\*(Aqt quote the output

grep 4 grep [-HhnlLoqvsriwFEz] [-m N] [-A/B/C N] PATTERN/-e PATTERN.../-f FILE [FILE]... .Sp Search for PATTERN in FILEs (or stdin) .Sp Options: .Sp -H Add \*(Aqfilename:\*(Aq prefix -h Do not add \*(Aqfilename:\*(Aq prefix -n Add \*(Aqline_no:\*(Aq prefix -l Show only names of files that match -L Show only names of files that don\*(Aqt 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 -F PATTERN is a literal (not regexp) -E PATTERN is an extended regexp -z Input is NUL terminated -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 \*(Aq-A N -B N\*(Aq -e PTRN Pattern to match -f FILE Read pattern from file

gunzip 4 gunzip [OPTIONS] [FILE]... .Sp Decompress FILEs (or stdin) .Sp Options: .Sp -c Write to stdout -f Force -t Test file integrity

gzip 4 gzip [OPTIONS] [FILE]... .Sp Compress FILEs (or stdin) .Sp Options: .Sp -d Decompress -c Write to stdout -f Force

head 4 head [OPTIONS] [FILE]... .Sp Print first 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a filename header. .Sp Options: .Sp -n N[kbm] Print first N lines -c N[kbm] Print first N bytes -q Never print headers -v Always print headers

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

hexdump 4 hexdump [-bcCdefnosvx] [FILE]... .Sp Display FILEs (or stdin) in a user specified format .Sp Options: .Sp -b One-byte octal display -c One-byte character display -C Canonical hex+ASCII, 16 bytes per line -d Two-byte decimal display -e FORMAT STRING -f FORMAT FILE -n LENGTH Interpret only LENGTH bytes of input -o Two-byte octal display -s OFFSET Skip OFFSET bytes -v Display all input data -x Two-byte hexadecimal display

hostid 4 hostid .Sp Print out a unique 32-bit identifier for the machine

hostname 4 hostname [OPTIONS] [HOSTNAME | -F FILE] .Sp Get or set hostname or DNS domain name .Sp Options: .Sp -s Short -i Addresses for the hostname -d DNS domain name -f Fully qualified domain name -F FILE Use FILE\*(Aqs content as hostname

httpd 4 httpd [-ifv[v]] [-c CONFFILE] [-p [IP:]PORT] [-r REALM] [-h HOME] or httpd -d/-e STRING .Sp Listen for incoming HTTP requests .Sp Options: .Sp -i Inetd mode -f Don\*(Aqt daemonize -v[v] Verbose -p [IP:]PORT Bind to ip:port (default *:80) -r REALM Authentication Realm for Basic Authentication -h HOME Home directory (default .) -c FILE Configuration file (default {/etc,HOME}/httpd.conf) -e STRING HTML encode STRING -d STRING URL decode STRING

id 4 id [OPTIONS] [USER] .Sp Print information about USER or the current user .Sp Options: .Sp -u Print user ID -g Print group ID -G Print supplementary group IDs -n Print name instead of a number -r Print real user ID instead of effective ID

ifconfig 4 ifconfig [-a] interface [address] .Sp Configure a network interface .Sp Options: .Sp [add ADDRESS[/PREFIXLEN]] [del ADDRESS[/PREFIXLEN]] [[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]] [netmask ADDRESS] [dstaddr ADDRESS] [outfill NN] [keepalive NN] [hw ether|infiniband ADDRESS] [metric NN] [mtu NN] [[-]trailers] [[-]arp] [[-]allmulti] [multicast] [[-]promisc] [txqueuelen NN] [[-]dynamic] [mem_start NN] [io_addr NN] [irq NN] [up|down] ...

ionice 4 ionice [-c 1-3] [-n 0-7] [-p PID] [PROG] .Sp Change I/O priority and class .Sp Options: .Sp -c Class. 1:realtime 2:best-effort 3:idle -n Priority

ip 4 ip [OPTIONS] {address | route | link | tunnel | rule} {COMMAND} .Sp ip [OPTIONS] OBJECT {COMMAND} where OBJECT := {address | route | link | tunnel | rule} OPTIONS := { -f[amily] { inet | inet6 | link } | -o[neline] }

ipcalc 4 ipcalc [OPTIONS] ADDRESS[[/]NETMASK] [NETMASK] .Sp Calculate IP network settings from a IP address .Sp Options: .Sp -b,--broadcast Display calculated broadcast address -n,--network Display calculated network address -m,--netmask Display default netmask for IP -p,--prefix Display the prefix for IP/NETMASK -h,--hostname Display first resolved host name -s,--silent Don\*(Aqt ever display error messages

kill 4 kill [-l] [-SIG] PID... .Sp Send a signal (default: TERM) to given PIDs .Sp Options: .Sp -l List all signal names and numbers

killall 4 killall [-l] [-q] [-SIG] PROCESS_NAME... .Sp Send a signal (default: TERM) to given processes .Sp Options: .Sp -l List all signal names and numbers -q Don\*(Aqt complain if no processes were killed

klogd 4 klogd [-c N] [-n] .Sp Kernel logger .Sp Options: .Sp -c N Only messages with level < N are printed to console -n Run in foreground

last 4 last .Sp Show listing of the last users that logged into the system

length 4 length STRING .Sp Print STRING's length

ln 4 ln [OPTIONS] TARGET... LINK|DIR .Sp Create a link LINK or DIR/TARGET to the specified TARGET(s) .Sp Options: .Sp -s Make symlinks instead of hardlinks -f Remove existing destinations -n Don\*(Aqt 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

loadfont 4 loadfont < font .Sp Load a console font from stdin

loadkmap 4 loadkmap < keymap .Sp Load a binary keyboard translation table from stdin

logger 4 logger [OPTIONS] [MESSAGE] .Sp Write MESSAGE (or stdin) to syslog .Sp Options: .Sp -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)

logname 4 logname .Sp Print the name of the current user

logread 4 logread [OPTIONS] .Sp Show messages in syslogd's circular buffer .Sp Options: .Sp -f Output data as log grows

losetup 4 losetup [-o OFS] LOOPDEV FILE - associate loop devices losetup -d LOOPDEV - disassociate losetup [-f] - show .Sp Options: .Sp -o OFS Start OFS bytes into FILE -f Show first free loop device

ls 4 ls [-1AacCdeFilnpLRrSsTtuvwxXhk] [FILE]... .Sp List directory contents .Sp Options: .Sp -1 List in a single column -A Don\*(Aqt list . and .. -a Don\*(Aqt hide entries starting with . -C List by columns -c With -l: sort by ctime --color[={always,never,auto}] Control coloring -d List directory entries instead of contents -e List full date and time -F Append indicator (one of ) to entries -i List inode numbers -l Long listing format -n List numeric UIDs and GIDs instead of names -p Append indicator (one of ) to entries -L List entries pointed to by symlinks -R Recurse -r Sort in reverse order -S Sort by file size -s List the size of each file, in blocks -T N Assume tabstop every N columns -t With -l: sort by modification time -u With -l: sort by access time -v Sort by version -w N Assume the terminal is N columns wide -x List by lines -X Sort by extension -h List sizes in human readable format (1K 243M 2G)

lzcat 4 lzcat FILE .Sp Decompress to stdout

lzma 4 lzma -d [OPTIONS] [FILE]... .Sp Decompress FILE (or stdin) .Sp Options: .Sp -d Decompress -c Write to stdout -f Force

md5sum 4 md5sum [OPTIONS] [FILE]... .Sp Print MD5 checksums

mkdir 4 mkdir [OPTIONS] DIRECTORY... .Sp Create DIRECTORY .Sp Options: .Sp -m Mode -p No error if exists; make parent directories as needed

mkfifo 4 mkfifo [OPTIONS] name .Sp Create named pipe (identical to 'mknod name p') .Sp Options: .Sp -m MODE Mode (default a=rw)

mknod 4 mknod [OPTIONS] NAME TYPE MAJOR MINOR .Sp Create a special file (block, character, or pipe) .Sp Options: .Sp -m Create the special file using the specified mode (default a=rw) TYPEs include: b: Make a block device c or u: Make a character device p: Make a named pipe (MAJOR and MINOR are ignored)

mktemp 4 mktemp [-dt] [-p DIR] [TEMPLATE] .Sp Create a temporary file with name based on TEMPLATE and print its name. TEMPLATE must end with XXXXXX (e.g. [/dir/]nameXXXXXX). .Sp Options: .Sp -d Make a directory instead of a file -t Generate a path rooted in temporary directory -p DIR Use DIR as a temporary directory (implies -t)

.Sp For -t or -p, directory is chosen as follows: \f(CW$TMPDIR\fR if set, else -p DIR, else /tmp

more 4 more [FILE]... .Sp View FILE (or stdin) one screenful at a time

mount 4 mount [OPTIONS] [-o OPTS] DEVICE NODE .Sp Mount a filesystem. Filesystem autodetection requires /proc. .Sp Options: .Sp -a Mount all filesystems in fstab -i Don\*(Aqt run mount helper -r Read-only mount -w Read-write mount (default) -t FSTYPE Filesystem type -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 bind Bind a file or directory to another location move Relocate an existing mount point remount Remount a mounted filesystem, changing flags ro/rw Same as -r/-w

.Sp There are filesystem-specific -o flags.

mt 4 mt [-f device] opcode value .Sp Control magnetic tape drive operation .Sp Available Opcodes: .Sp bsf bsfm bsr bss datacompression drvbuffer eof eom erase fsf fsfm fsr fss load lock mkpart nop offline ras1 ras2 ras3 reset retension rewind rewoffline seek setblk setdensity setpart tell unload unlock weof wset

mv 4 mv [OPTIONS] SOURCE DEST or: mv [OPTIONS] SOURCE... DIRECTORY .Sp Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY .Sp Options: .Sp -f Don\*(Aqt prompt before overwriting -i Interactive, prompt before overwrite

nameif 4 nameif [-s] [-c FILE] [{IFNAME MACADDR}] .Sp Rename network interface while it in the down state .Sp Options: .Sp -c FILE Use configuration file (default: /etc/mactab) -s Use syslog (LOCAL0 facility) IFNAME MACADDR new_interface_name interface_mac_address

nc 4 nc [IPADDR PORT] .Sp Open a pipe to IP:PORT

netstat 4 netstat [-laentuwxr] .Sp Display networking information .Sp Options: .Sp -l Display listening server sockets -a Display all sockets (default: connected) -e Display other/more information -n Don\*(Aqt resolve names -t Tcp sockets -u Udp sockets -w Raw sockets -x Unix sockets -r Display routing table

nslookup 4 nslookup [HOST] [SERVER] .Sp Query the nameserver for the IP address of the given HOST optionally using a specified DNS server

od 4 od [-aBbcDdeFfHhIiLlOovXx] [-t TYPE] [FILE] .Sp Write an unambiguous representation, octal bytes by default, of FILE (or stdin) to stdout

openvt 4 openvt [-c N] [-sw] [PROG ARGS] .Sp Start PROG on a new virtual terminal .Sp Options: .Sp -c N Use specified VT -s Switch to the VT -w Wait for PROG to exit

patch 4 patch [OPTIONS] [ORIGFILE [PATCHFILE]] .Sp -p,--strip N Strip N leading components from file names -i,--input DIFF Read DIFF instead of stdin -R,--reverse Reverse patch -N,--forward Ignore already applied patches --dry-run Don\*(Aqt actually change files

pidof 4 pidof [NAME]... .Sp List PIDs of all processes with names that match NAMEs

ping 4 ping [OPTIONS] HOST .Sp Send ICMP ECHO_REQUEST packets to network hosts .Sp Options: .Sp -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 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 displays output at start and when finished

ping6 4 ping6 [OPTIONS] HOST .Sp Send ICMP ECHO_REQUEST packets to network hosts .Sp Options: .Sp -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 displays output at start and when finished

printf 4 printf FORMAT [ARGUMENT]... .Sp Format and print ARGUMENT(s) according to FORMAT, where FORMAT controls the output exactly as in C printf

ps 4 ps [-o COL1,COL2=HEADER] [-T] .Sp Show list of processes .Sp Options: .Sp -o COL1,COL2=HEADER Select columns for display -T Show threads

pwd 4 pwd .Sp Print the full filename of the current working directory

rdate 4 rdate [-sp] HOST .Sp Get and possibly set the system date and time from a remote HOST .Sp Options: .Sp -s Set the system date and time (default) -p Print the date and time

readlink 4 readlink [-fnv] FILE .Sp Display the value of a symlink .Sp Options: .Sp -f Canonicalize by following all symlinks -n Don\*(Aqt add newline -v Verbose

realpath 4 realpath FILE... .Sp Return the absolute pathnames of given FILE

renice 4 renice {{-n INCREMENT} | PRIORITY} [[-p | -g | -u] ID...] .Sp Change scheduling priority for a running process .Sp Options: .Sp -n Adjust current nice value (smaller is faster) -p Process id(s) (default) -g Process group id(s) -u Process user name(s) and/or id(s)

reset 4 reset .Sp Reset the screen

rev 4 rev [FILE]... .Sp Reverse lines of FILE

rm 4 rm [OPTIONS] FILE... .Sp Remove (unlink) FILEs .Sp Options: .Sp -i Always prompt before removing -f Never prompt -R,-r Recurse

rmdir 4 rmdir [OPTIONS] DIRECTORY... .Sp Remove DIRECTORY if it is empty .Sp Options: .Sp -p|--parents Include parents --ignore-fail-on-non-empty

route 4 route [{add|del|delete}] .Sp Edit kernel routing tables .Sp Options: .Sp -n Don\*(Aqt resolve names -e Display other/more information -A inet{6} Select address family

rpm 4 rpm -i PACKAGE.rpm; rpm -qp[ildc] PACKAGE.rpm .Sp Manipulate RPM packages .Sp Commands: .Sp -i Install package -qp Query package Options: -i Show information -l List contents -d List documents -c List config files

rpm2cpio 4 rpm2cpio package.rpm .Sp Output a cpio archive of the rpm file

run-parts 4 run-parts [-t] [-a ARG] [-u MASK] DIRECTORY .Sp Run a bunch of scripts in DIRECTORY .Sp Options: .Sp -t Print what would be run, but don\*(Aqt actually run anything -a ARG Pass ARG as argument for every program -u MASK Set the umask to MASK before running every program

sed 4 sed [-efinr] SED_CMD [FILE]... .Sp Options: .Sp -e CMD Add CMD to sed commands to be executed -f FILE Add FILE contents to sed commands to be executed -i Edit files in-place (else sends result to stdout) -n Suppress automatic printing of pattern space -r Use extended regex syntax

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

setkeycodes 4 setkeycodes SCANCODE KEYCODE... .Sp Set entries into the kernel's scancode-to-keycode map, allowing unusual keyboards to generate usable keycodes. .Sp SCANCODE may be either xx or e0xx (hexadecimal), and KEYCODE is given in decimal.

sha1sum 4 sha1sum [OPTIONS] [FILE]... .Sp Print SHA1 checksums

sha256sum 4 sha256sum [OPTIONS] [FILE]... .Sp Print SHA256 checksums

sha512sum 4 sha512sum [OPTIONS] [FILE]... .Sp Print SHA512 checksums

sleep 4 sleep [N]... .Sp 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 4 sort [-nrugMcszbdfimSTokt] [-o FILE] [-k start[.offset][opts][,end[.offset][opts]] [-t CHAR] [FILE]... .Sp Sort lines of text .Sp Options: .Sp -b Ignore leading blanks -c Check whether input is sorted -d Dictionary order (blank or alphanumeric only) -f Ignore case -g General numerical sort -i Ignore unprintable characters -k Sort key -M Sort month -n Sort numbers -o Output to file -k Sort by key -t CHAR Key separator -r Reverse sort order -s Stable (don\*(Aqt sort ties alphabetically) -u Suppress duplicate lines -z Lines are terminated by NUL, not newline -mST Ignored for GNU compatibility

start-stop-daemon 4 start-stop-daemon [OPTIONS] [-S|-K] ... [-- ARGS...] .Sp Search for matching processes, and then -K: stop all matching processes. -S: start a process unless a matching process is found. .Sp Process matching: .Sp -u,--user USERNAME|UID Match only this user\*(Aqs processes -n,--name NAME Match processes with NAME in comm field in /proc/PID/stat -x,--exec EXECUTABLE Match processes with this command in /proc/PID/cmdline -p,--pidfile FILE Match a process with PID from the file All specified conditions must match -S only: -x,--exec EXECUTABLE Program to run -a,--startas NAME Zeroth argument -b,--background Background -N,--nicelevel N Change nice level -c,--chuid USER[:[GRP]] Change to user/group -m,--make-pidfile Write PID to the pidfile specified by -p -K only: -s,--signal SIG Signal to send -t,--test Match only, exit with 0 if a process is found Other: -o,--oknodo Exit with status 0 if nothing is done -v,--verbose Verbose -q,--quiet Quiet

strings 4 strings [-afo] [-n LEN] [FILE]... .Sp Display printable strings in a binary file .Sp Options: .Sp -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

stty 4 stty [-a|g] [-F DEVICE] [SETTING]... .Sp Without arguments, prints baud rate, line discipline, and deviations from stty sane .Sp Options: .Sp -F DEVICE Open device instead of stdin -a Print all current settings in human-readable form -g Print in stty-readable form [SETTING] See manpage

swapoff 4 swapoff [-a] [DEVICE] .Sp Stop swapping on DEVICE .Sp Options: .Sp -a Stop swapping on all swap devices

swapon 4 swapon [-a] [DEVICE] .Sp Start swapping on DEVICE .Sp Options: .Sp -a Start swapping on all swap devices

sync 4 sync .Sp Write all buffered blocks to disk

sysctl 4 sysctl [OPTIONS] [VALUE]... .Sp Configure kernel parameters at runtime .Sp Options: .Sp -n Don\*(Aqt print key names -e Don\*(Aqt warn about unknown keys -w Change sysctl setting -p FILE Load sysctl settings from FILE (default /etc/sysctl.conf) -a Display all values -A Display all values in table form

syslogd 4 syslogd [OPTIONS] .Sp System logging utility. This version of syslogd ignores /etc/syslog.conf .Sp Options: .Sp -n Run in foreground -O FILE Log to given file (default:/var/log/messages) -l N Set local log level -S Smaller logging output -R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP) -L Log locally and via network (default is network only if -R) -C[size(KiB)] Log to shared mem buffer (read it using logread)

tac 4 tac [FILE]... .Sp Concatenate FILEs and print them in reverse

tail 4 tail [OPTIONS] [FILE]... .Sp Print last 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a filename header. .Sp Options: .Sp -f Print data as file grows -s SECONDS Wait SECONDS between reads with -f -n N[kbm] Print last N lines -c N[kbm] Print last N bytes -q Never print headers -v Always print headers

.Sp N may be suffixed by k (x1024), b (x512), or m (x1024^2). If N starts with a '+', output begins with the Nth item from the start of each file, not from the end.

tar 4 tar -[cxtzjaZmvO] [-f TARFILE] [-C DIR] [FILE]... .Sp Create, extract, or list files from a tar file .Sp Operation: .Sp c Create x Extract t List Options: f Name of TARFILE (\*(Aq-\*(Aq for stdin/out) C Change to DIR before operation v Verbose z (De)compress using gzip j (De)compress using bzip2 a (De)compress using lzma Z (De)compress using compress O Extract to stdout h Follow symlinks m Don\*(Aqt restore mtime

tee 4 tee [OPTIONS] [FILE]... .Sp Copy stdin to each FILE, and also to stdout .Sp Options: .Sp -a Append to the given FILEs, don\*(Aqt overwrite -i Ignore interrupt signals (SIGINT)

telnet 4 telnet [-a] [-l USER] HOST [PORT] .Sp Connect to telnet server .Sp Options: .Sp -a Automatic login with $USER variable -l USER Automatic login as USER

test 4 test EXPRESSION ] .Sp Check file types, compare values etc. Return a 0/1 exit code depending on logical value of EXPRESSION

tftp 4 tftp [OPTIONS] HOST [PORT] .Sp Transfer a file from/to tftp server .Sp Options: .Sp -l FILE Local FILE -r FILE Remote FILE -g Get file -p Put file -b SIZE Transfer blocks of SIZE octets

time 4 time [OPTIONS] PROG ARGS .Sp Run PROG, display resource usage when it exits .Sp Options: .Sp -v Verbose

top 4 top [-b] [-nCOUNT] [-dSECONDS] .Sp 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.

touch 4 touch [-c] [-d DATE] FILE [FILE]... .Sp Update the last-modified date on the given FILE[s] .Sp Options: .Sp -c Don\*(Aqt create files -d DT Date/time to use

tr 4 tr [-cds] STRING1 [STRING2] .Sp Translate, squeeze, or delete characters from stdin, writing to stdout .Sp Options: .Sp -c Take complement of STRING1 -d Delete input characters coded STRING1 -s Squeeze multiple output characters of STRING2 into one character

traceroute 4 traceroute [-46FIldnrv] [-f 1ST_TTL] [-m MAXTTL] [-p PORT] [-q PROBES] [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-g GATEWAY] [-i IFACE] [-z PAUSE_MSEC] HOST [BYTES] .Sp Trace the route to HOST .Sp Options: .Sp -4, -6 Force IP or IPv6 name resolution -F Set the don\*(Aqt fragment bit -I Use ICMP ECHO instead of UDP datagrams -l Display the TTL value of the returned packet -d Set SO_DEBUG options to socket -n Print numeric addresses -r Bypass routing tables, send directly to HOST -v Verbose -m Max time-to-live (max number of hops) -p Base UDP port number used in probes (default 33434) -q Number of probes per TTL (default 3) -s IP address to use as the source address -t Type-of-service in probe packets (default 0) -w Time in seconds to wait for a response (default 3) -g Loose source route gateway (8 max)

traceroute6 4 traceroute6 [-dnrv] [-m MAXTTL] [-p PORT] [-q PROBES] [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-i IFACE] HOST [BYTES] .Sp Trace the route to HOST .Sp Options: .Sp -d Set SO_DEBUG options to socket -n Print numeric addresses -r Bypass routing tables, send directly to HOST -v Verbose -m Max time-to-live (max number of hops) -p Base UDP port number used in probes (default is 33434) -q Number of probes per TTL (default 3) -s IP address to use as the source address -t Type-of-service in probe packets (default 0) -w Time in seconds to wait for a response (default 3)

true 4 true .Sp Return an exit code of TRUE (0)

tty 4 tty .Sp Print file name of stdin's terminal .Sp Options: .Sp -s Print nothing, only return exit status

udhcpc 4 udhcpc [-fbnqvoCR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE] [-H HOSTNAME] [-c CID] [-V VENDOR] [-O DHCP_OPT]... .Sp -i,--interface IFACE Interface to use (default eth0) -p,--pidfile FILE Create pidfile -r,--request IP IP address to request -s,--script PROG Run PROG at DHCP events (default /usr/share/udhcpc/default.script) -t,--retries N Send up to N discover packets -T,--timeout N Pause between packets (default 3 seconds) -A,--tryagain N Wait N seconds after failure (default 20) -f,--foreground Run in foreground -b,--background Background if lease is not obtained -S,--syslog Log to syslog too -n,--now Exit if lease is not obtained -q,--quit Exit after obtaining lease -R,--release Release IP on exit -a,--arping Use arping to validate offered address -O,--request-option OPT Request DHCP option OPT (cumulative) -o,--no-default-options Don\*(Aqt request any options (unless -O is given) -x OPT:VAL Include option OPT in sent packets (cumulative) -F,--fqdn NAME Ask server to update DNS mapping for NAME -H,-h,--hostname NAME Send NAME as client hostname (default none) -V,--vendorclass VENDOR Vendor identifier (default \*(Aqudhcp VERSION\*(Aq) -c,--clientid CLIENTID Client identifier (default own MAC) -C,--clientid-none Don\*(Aqt send client identifier

udhcpd 4 udhcpd [-fS] [configfile] .Sp DHCP server .Sp -f Run in foreground -S Log to syslog too

umount 4 umount [OPTIONS] FILESYSTEM|DIRECTORY .Sp Unmount file systems .Sp Options: .Sp -a Unmount all 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 Free loop device if it has been used

uname 4 uname [-amnrspv] .Sp Print system information .Sp Options: .Sp -a Print all -m The machine (hardware) type -n Hostname -r OS release -s OS name (default) -p Processor type -v OS version

uncompress 4 uncompress [-cf] [FILE]... .Sp Decompress .Z file[s] .Sp Options: .Sp -c Write to stdout -f Overwrite

uniq 4 uniq [-cdu][-f,s,w N] [INPUT [OUTPUT]] .Sp Discard duplicate lines .Sp Options: .Sp -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 4 unix2dos [OPTIONS] [FILE] .Sp Convert FILE in-place from Unix to DOS format. When no file is given, use stdin/stdout. .Sp Options: .Sp -u dos2unix -d unix2dos

unlzma 4 unlzma [OPTIONS] [FILE]... .Sp Decompress FILE (or stdin) .Sp Options: .Sp -c Write to stdout -f Force

unxz 4 unxz [OPTIONS] [FILE]... .Sp Decompress FILE (or stdin) .Sp Options: .Sp -c Write to stdout -f Force

unzip 4 unzip [-opts[modifiers]] FILE[.zip] [LIST] [-x XLIST] [-d DIR] .Sp Extract files from ZIP archives .Sp Options: .Sp -l List archive contents (with -q for short form) -n Never overwrite files (default) -o Overwrite -p Send output to stdout -q Quiet -x XLST Exclude these files -d DIR Extract files into DIR

uptime 4 uptime .Sp Display the time since the last boot

usleep 4 usleep N .Sp Pause for N microseconds

uudecode 4 uudecode [-o OUTFILE] [INFILE] .Sp Uudecode a file Finds outfile name in uuencoded source unless -o is given

uuencode 4 uuencode [-m] [INFILE] STORED_FILENAME .Sp Uuencode a file to stdout .Sp Options: .Sp -m Use base64 encoding per RFC1521

vi 4 vi [OPTIONS] [FILE]... .Sp Edit FILE .Sp Options: .Sp -c Initial command to run ($EXINIT also available) -R Read-only -H Short help regarding available features

watch 4 watch [-n SEC] [-t] PROG ARGS .Sp Run PROG periodically .Sp Options: .Sp -n Loop period in seconds (default 2) -t Don\*(Aqt print header

watchdog 4 watchdog [-t N[ms]] [-T N[ms]] [-F] DEV .Sp Periodically write to watchdog device DEV .Sp Options: .Sp -T N Reboot after N seconds if not reset (default 60) -t N Reset every N seconds (default 30) -F Run in foreground

.Sp Use 500ms to specify period in milliseconds

wc 4 wc [OPTIONS] [FILE]... .Sp Print line, word, and byte counts for each FILE (or stdin), and a total line if more than one FILE is specified .Sp Options: .Sp -c Print the byte counts -l Print the newline counts -L Print the length of the longest line -w Print the word counts

wget 4 wget [-c|--continue] [-s|--spider] [-q|--quiet] [-O|--output-document FILE] [--header 'header: value'] [-Y|--proxy on/off] [-P DIR] [--no-check-certificate] [-U|--user-agent AGENT] URL .Sp Retrieve files via HTTP or FTP .Sp Options: .Sp -s Spider mode - only check file existence -c Continue retrieval of aborted transfer -q Quiet -P Set directory prefix to DIR -O FILE Save to FILE (\*(Aq-\*(Aq for stdout) -U STR Use STR for User-Agent header -Y Use proxy (\*(Aqon\*(Aq or \*(Aqoff\*(Aq)

which 4 which [COMMAND]... .Sp Locate a COMMAND

who 4 who [-a] .Sp Show who is logged on .Sp Options: .Sp -a Show all

whoami 4 whoami .Sp Print the user name associated with the current effective user id

xargs 4 xargs [OPTIONS] [PROG ARGS] .Sp Run PROG on every item given by stdin .Sp Options: .Sp -r Don\*(Aqt run command if input is empty -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

xz 4 xz -d [OPTIONS] [FILE]... .Sp Decompress FILE (or stdin) .Sp Options: .Sp -d Decompress -c Write to stdout -f Force

xzcat 4 xzcat FILE .Sp Decompress to stdout

yes 4 yes [STRING] .Sp Repeatedly output a line with STRING, or 'y'

zcat 4 zcat FILE .Sp Decompress to stdout


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.


Denis Vlasenko <>


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 <> run-parts

Erik Andersen <>

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 <>

rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm

Jeff Angielski <>

ftpput, ftpget

Edward Betts <>

expr, hostid, logname, whoami

John Beppu <>

du, nslookup, sort

Brian Candler <>


Randolph Chung <>

fbset, ping, hostname

Dave Cinege <>

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

Jordan Crouse <>


Magnus Damm <>

tftp client insmod powerpc support

Larry Doolittle <>

pristine source directory compilation, lots of patches and fixes.

Glenn Engel <>


Gennady Feldman <>

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

Karl M. Hegbloom <>

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

Daniel Jacobowitz <>


Matt Kraai <>

documentation, bugfixes, test suite

Stephan Linz <>

ipcalc, Red Hat equivalence

John Lombardo <>


Glenn McGrath <>

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

Manuel Novoa III <>

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 <>

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 <>

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

Tim Riker <>

bug fixes, member of fan club

Kent Robotti <>

reset, tons and tons of bug reports and patches.

Chip Rosenthal <>, <>

wget - Contributed by permission of Covad Communications

Pavel Roskin <>

Lots of bugs fixes and patches.

Gyepi Sam <>

Remote logging feature for syslogd

Linus Torvalds <>

mkswap, fsck.minix, mkfs.minix

Mark Whitley <>

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

Charles P. Wright <>

gzip, mini-netcat(nc)

Enrique Zanardi <>

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

Tito Ragusa <>

devfsd and size optimizations in strings, openvt and deallocvt.