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:
[, [[, addgroup, adduser, ar, arping, ash, awk, basename, bunzip2, bzcat, cat, catv, chattr, chgrp, chmod, chown, chroot, chrt, chvt, cksum, clear, cmp, cp, cpio, crond, crontab, cut, date, dc, dd, deallocvt, delgroup, deluser, devmem, df, diff, dirname, dmesg, dnsd, dnsdomainname, dos2unix, du, dumpkmap, echo, egrep, eject, env, ether-wake, expr, false, fdflush, fdformat, fgrep, find, fold, free, freeramdisk, fsck, ftpd, ftpget, ftpput, fuser, getopt, getty, grep, gunzip, gzip, halt, hdparm, head, hexdump, hostid, hostname, httpd, hwclock, id, ifconfig, ifdown, ifup, inetd, init, insmod, install, ip, ipaddr, ipcrm, ipcs, iplink, iproute, iprule, iptunnel, kill, killall, killall5, klogd, last, length, less, linux32, linux64, linuxrc, ln, loadfont, loadkmap, logger, login, logname, losetup, ls, lsattr, lsmod, lspci, lsusb, lzmacat, makedevs, md5sum, mdev, mesg, mkdir, mke2fs, mkfifo, mkfs.ext2, mknod, mkswap, mktemp, modprobe, more, mount, mountpoint, mt, mv, nameif, netstat, nice, nohup, nslookup, od, openvt, passwd, patch, pidof, ping, pipe_progress, pivot_root, poweroff, printenv, printf, ps, pwd, rdate, readlink, readprofile, realpath, reboot, renice, reset, resize, rm, rmdir, rmmod, route, run-parts, runlevel, sed, seq, setarch, setconsole, setkeycodes, setlogcons, setsid, sh, sha1sum, sha256sum, sha512sum, sleep, sort, start-stop-daemon, strings, stty, su, sulogin, swapoff, swapon, switch_root, sync, sysctl, syslogd, tail, tar, tee, telnet, telnetd, test, tftp, time, top, touch, tr, traceroute, true, tty, tune2fs, udhcpc, umount, uname, uniq, unix2dos, unlzma, unzip, uptime, usleep, uudecode, uuencode, vconfig, vi, vlock, watch, watchdog, wc, wget, which, who, whoami, xargs, yes, zcat
addgroup [-g GID] GROUP
Add a group
Options:
-g GID Group id -S Create a system group
adduser [OPTIONS] USER
Add a user
Options:
-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
ar [-o] [-v] [-p] [-t] [-x] ARCHIVE FILES
Extract or list FILES from an ar archive
Options:
-o Preserve original dates -p Extract to stdout -t List -x Extract -v Verbose
arping [-fqbDUA] [-c CNT] [-w TIMEOUT] [-I IFACE] [-s SRC_IP] DST_IP
Send ARP requests/replies
Options:
-f Quit on first ARP reply -q Quiet -b Keep broadcasting, don't 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 [OPTIONS] [AWK_PROGRAM] [FILE]...
Options:
-v VAR=VAL Set variable -F SEP Use SEP as field separator -f FILE Read program from FILE
basename FILE [SUFFIX]
Strip directory path and .SUFFIX from FILE
bunzip2 [OPTIONS] [FILE]...
Uncompress FILEs (or stdin)
Options:
-c Write to stdout -f Force
bzcat FILE
Uncompress to stdout
cat [-u] [FILE]...
Concatenate FILEs and print them to stdout
Options:
-u Use unbuffered i/o (ignored)
catv [-etv] [FILE]...
Display nonprinting characters as ^x or M-x
Options:
-e End each line with $ -t Show tabs as ^I -v Don't use ^x or M-x escapes
chattr [-R] [-+=AacDdijsStTu] [-v VERSION] [FILE]...
Change file attributes on an ext2 fs
Modifiers:
- Remove attributes + Add attributes = Set attributes Attributes:
A Don't track atime a Append mode only c Enable compress D Write dir contents synchronously d Don't backup with dump i Cannot be modified (immutable) j Write all data to journal first s Zero disk storage when deleted S Write file contents synchronously t Disable tail-merging of partial blocks with other files u Allow file to be undeleted Options:
-R Recurse -v Set the file's version/generation number
chgrp [-RhLHPcvf]... GROUP FILE...
Change the group membership of each FILE to GROUP
Options:
-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) -c List changed files -v Verbose -f Hide errors
chmod [-Rcvf] 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
Options:
-R Recurse -c List changed files -v List all files -f Hide errors
chown [-RhLHPcvf]... OWNER[<.|:>[GROUP]] FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP
Options:
-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) -c List changed files -v List all files -f Hide errors
chroot NEWROOT [PROG ARGS]
Run PROG with root directory set to NEWROOT
chrt [OPTIONS] [PRIO] [PID | PROG ARGS]
Manipulate real-time attributes of a process
Options:
-p Operate on PID -r Set SCHED_RR scheduling -f Set SCHED_FIFO scheduling -o Set SCHED_OTHER scheduling -m Show min and max priorities
chvt N
Change the foreground virtual terminal to /dev/ttyN
cksum FILES...
Calculate the CRC32 checksums of FILES
clear
Clear screen
cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]]
Compares FILE1 vs stdin if FILE2 is not specified
Options:
-l Write the byte numbers (decimal) and values (octal) for all differing bytes -s Quiet
cp [OPTIONS] SOURCE DEST
Copy SOURCE to DEST, or multiple SOURCE(s)
to DIRECTORY
Options:
-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 Force overwrite -i Prompt before overwrite -l,-s Create (sym)links
cpio [-dmvu] [-F FILE] [-ti]
Extract or list files from a cpio archive
Main operation mode:
-t List -i Extract Options:
-d Make leading directories -m Preserve mtime -v Verbose -u Overwrite -F FILE Input (-t,-i,-p) or output (-o) file
crond -fbS -l N -L LOGFILE -c DIR
-f Foreground -b Background (default) -S Log to syslog (default) -l Set log level. 0 is the most verbose, default 8 -L Log to file -c Working dir
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 [OPTIONS] [FILE]...
Print selected fields from each input FILE to stdout
Options:
-b LIST Output only bytes from LIST -c LIST Output only characters from LIST -d CHAR Use CHAR instead of tab as the field delimiter -s Output only the lines containing delimiter -f N Print only these fields -n Ignored
date [OPTIONS] [+FMT] [TIME]
Display time (using +FMT), or set time
Options:
[-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]
dc expression...
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 [if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N] [skip=N] | |
[seek=N] [conv=notrunc|noerror|sync|fsync] |
Copy a file with converting and formatting
Options:
if=FILE Read from FILE instead of stdin of=FILE Write to FILE instead of stdout bs=N Read and write N bytes at a time ibs=N Read N bytes at a time obs=N Write N bytes at a time count=N Copy only N input blocks skip=N Skip N input blocks seek=N Skip N output blocks conv=notrunc Don't truncate output file conv=noerror Continue after read errors conv=sync Pad blocks with zeros conv=fsync Physically write data out before finishing
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 [N]
Deallocate unused virtual terminal /dev/ttyN
delgroup GROUP
Delete group GROUP from the system
deluser USER
Delete USER from the system
devmem ADDRESS [WIDTH [VALUE]]
Read/write from physical address
ADDRESS Address to act upon WIDTH Width (8/16/...) VALUE Data to be written
df [-Pkmh] [FILESYSTEM]...
Print filesystem usage statistics
Options:
-P POSIX output format -k 1024-byte blocks (default) -m 1M-byte blocks -h Human readable (e.g. 1K 243M 2G)
diff [-abBdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] FILE1 FILE2
Compare files line by line and output the differences between them. This implementation supports unified diffs only.
Options:
-a Treat all files as text -b Ignore changes in the amount of whitespace -B Ignore changes whose lines are all blank -d Try hard to find a smaller set of changes -i Ignore case differences -L Use LABEL instead of the filename in the unified header -N Treat absent files as empty -q Output only whether files differ -r Recurse -S Start with FILE when comparing directories -T Make tabs line up by prefixing a tab when necessary -s Report when two files are the same -t Expand tabs to spaces in output -U Output LINES lines of context -w Ignore all whitespace
dirname FILENAME
Strip non-directory suffix from FILENAME
dmesg [-c] [-n LEVEL] [-s SIZE]
Print or control the kernel ring buffer
Options:
-c Clear ring buffer after printing -n LEVEL Set console logging level -s SIZE Buffer size
dnsd [-dvs] [-c CONFFILE] [-t TTL_SEC] [-p PORT] [-i ADDR]
Small static DNS server daemon
Options:
-c FILE Config file -t SEC TTL -p PORT Listen on PORT -i ADDR Listen on ADDR -d Daemonize -v Verbose -s Send successful replies only. Use this if you want to use /etc/resolv.conf with two nameserver lines: nameserver DNSD_SERVER nameserver NORNAL_DNS_SERVER
dos2unix [OPTIONS] [FILE]
Convert FILE in-place from DOS to Unix format. When no file is given, use stdin/stdout.
Options:
-u dos2unix -d unix2dos
du [-aHLdclsxhmk] [FILE]...
Summarize disk space used for each FILE and/or directory. Disk space is printed in units of 1024 bytes.
Options:
-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 > keymap
Print a binary keyboard translation table to stdout
echo [-neE] [ARG]...
Print the specified ARGs to stdout
Options:
-n Suppress trailing newline -e Interpret backslash-escaped characters (i.e., \t=tab) -E Disable interpretation of backslash-escaped characters
eject [-t] [-T] [DEVICE]
Eject DEVICE or default /dev/cdrom
Options:
-t Close tray -T Open/close tray (toggle)
env [-iu] [-] [name=value]... [PROG ARGS]
Print the current environment or run PROG after setting up the specified environment
Options:
-, -i Start with an empty environment -u Remove variable from the environment
ether-wake [-b] [-i iface] [-p aa:bb:cc:dd[:ee:ff]] 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.
Options:
-b Send wake-up packet to the broadcast address -i iface Interface to use (default eth0) -p pass Append four or six byte password PW to the packet
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.
false
Return an exit code of FALSE (1)
fdflush DEVICE
Force floppy disk drive to detect disk change
fdformat [-n] DEVICE
Format floppy disk
Options:
-n Don't verify after format
find [PATH]... [EXPRESSION]
Search for files. The default PATH is the current directory, default EXPRESSION is '-print'
EXPRESSION may consist of:
-follow Follow symlinks -xdev Don't 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't 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's -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 -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 [-bs] [-w WIDTH] [FILE]...
Wrap input lines in each FILE (or stdin), writing to stdout
Options:
-b Count bytes rather than columns -s Break at spaces -w Use WIDTH columns instead of 80
free
Display the amount of free and used system memory
freeramdisk DEVICE
Free all memory used by the specified ramdisk
fsck [-ANPRTV] [-C FD] [-t FSTYPE] [FS_OPTS] [BLOCKDEV]...
Check and repair filesystems
Options:
-A Walk /etc/fstab and check all filesystems -N Don't execute, just show what would be done -P With -A, check filesystems in parallel -R With -A, skip the root filesystem -T Don't show title on startup -V Verbose -C n Write status information to specified filedescriptor -t TYPE List of filesystem types to check
ftpd [-wvS] [-t N] [-T N] [DIR]
Anonymous FTP server
ftpd should be used as an inetd service. ftpd's line for inetd.conf: 21 stream tcp nowait root ftpd ftpd /files/to/serve It also can be ran from tcpsvd:
tcpsvd -vE 0.0.0.0 21 ftpd /files/to/serve
Options:
-w Allow upload -v Log to stderr -S Log to syslog -t,-T Idle and absolute timeouts DIR Change root to this directory
ftpget [OPTIONS] HOST [LOCAL_FILE] REMOTE_FILE
Retrieve a remote file via FTP
Options:
-c,--continue Continue previous transfer -v,--verbose Verbose -u,--username Username -p,--password Password -P,--port Port number
ftpput [OPTIONS] HOST [REMOTE_FILE] LOCAL_FILE
Store a local file on a remote machine via FTP
Options:
-v,--verbose Verbose -u,--username Username -p,--password Password -P,--port Port number
fuser [OPTIONS] FILE or PORT/PROTO
Find processes which use FILEs or PORTs
Options:
-m Find processes which use same fs as FILEs -4 Search only IPv4 space -6 Search only IPv6 space -s Silent: just exit with 0 if any processes are found -k Kill found processes (otherwise display PIDs) -SIGNAL Signal to send (default: TERM)
getopt [OPTIONS]
Options:
-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't quote the output
getty [OPTIONS] BAUD_RATE TTY [TERMTYPE]
Open a tty, prompt for a login name, then invoke /bin/login
Options:
-h Enable hardware (RTS/CTS) flow control -i Don't display /etc/issue before running login -L Local line, don't do carrier detect -m Get baud rate from modem's CONNECT status message -w Wait for a CR or LF before sending /etc/issue -n Don't prompt the user for a login name -f ISSUE_FILE Display ISSUE_FILE instead of /etc/issue -l LOGIN Invoke LOGIN instead of /bin/login -t SEC Terminate after SEC if no username is read -I INITSTR Send INITSTR before anything else -H HOST Log HOST into the utmp file as the hostname
grep [-HhnlLoqvsriwFE] [-m N] [-A/B/C N] PATTERN/-e PATTERN.../-f FILE [FILE]...
Search for PATTERN in FILEs (or stdin)
Options:
-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 -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 [OPTIONS] [FILE]...
Uncompress FILEs (or stdin)
Options:
-c Write to stdout -f Force -t Test file integrity
gzip [OPTIONS] [FILE]...
Compress FILEs (or stdin)
Options:
-c Write to stdout -d Decompress -f Force
halt [-d DELAY] [-n] [-f] [-w]
Halt the system
Options:
-d Delay interval for halting -n No call to sync() -f Force halt (don't go through init) -w Only write a wtmp record
hdparm [OPTIONS] [DEVICE]
Options:
-a Get/set fs readahead -A Set drive read-lookahead flag (0/1) -b Get/set bus state (0 == off, 1 == on, 2 == tristate) -B Set Advanced Power Management setting (1-255) -c Get/set IDE 32-bit IO setting -C Check IDE power mode status -D Enable/disable drive defect-mgmt -f Flush buffer cache for device on exit -g Display drive geometry -h Display terse usage information -i Display drive identification -I Detailed/current information directly from drive -k Get/set keep_settings_over_reset flag (0/1) -K Set drive keep_features_over_reset flag (0/1) -L Set drive doorlock (0/1) (removable harddisks only) -m Get/set multiple sector count -n Get/set ignore-write-errors flag (0/1) -p Set PIO mode on IDE interface chipset (0,1,2,3,4,...) -P Set drive prefetch count -Q Get/set DMA tagged-queuing depth (if supported) -r Get/set readonly flag (DANGEROUS to set) -S Set standby (spindown) timeout -t Perform device read timings -T Perform cache read timings -u Get/set unmaskirq flag (0/1) -v Defaults; same as -mcudkrag for IDE drives -V Display program version and exit immediately -W Set drive write-caching flag (0/1) (DANGEROUS) -X Set IDE xfer mode (DANGEROUS) -y Put IDE drive in standby mode -Y Put IDE drive to sleep -Z Disable Seagate auto-powersaving mode -z Reread partition table
head [OPTIONS] [FILE]...
Print first 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a header giving the file name.
Options:
-n N Print first N lines instead of first 10 -c N Output the first N bytes -q Never output headers giving file names -v Always output headers giving file names
hexdump [-bcCdefnosvx] [FILE]...
Display FILEs (or stdin) in a user specified format
Options:
-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
Print out a unique 32-bit identifier for the machine
hostname [OPTIONS] [HOSTNAME | -F FILE]
Get or set hostname or DNS domain name
Options:
-s Short -i Addresses for the hostname -d DNS domain name -f Fully qualified domain name -F FILE Use FILE's content as hostname
httpd [-ifv[v]] [-c CONFFILE] [-p [IP:]PORT] [-u USER[:GRP]] [-r REALM] [-h HOME] or httpd -d/-e/-m STRING
Listen for incoming HTTP requests
Options:
-i Inetd mode -f Don't daemonize -v[v] Verbose -c FILE Configuration file (default httpd.conf) -p [IP:]PORT Bind to ip:port (default *:80) -u USER[:GRP] Set uid/gid after binding to port -r REALM Authentication Realm for Basic Authentication -h HOME Home directory (default .) -m STRING MD5 crypt STRING -e STRING HTML encode STRING -d STRING URL decode STRING
hwclock [-r|--show] [-s|--hctosys] [-w|--systohc] [-l|--localtime] [-u|--utc] [-f FILE]
Query and set hardware clock (RTC)
Options:
-r Show hardware clock time -s Set system time from hardware clock -w Set hardware clock to system time -u Hardware clock is in UTC -l Hardware clock is in local time -f FILE Use specified device (e.g. /dev/rtc2)
id [OPTIONS] [USER]
Print information about USER or the current user
Options:
-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 [-a] interface [address]
Configure a network interface
Options:
[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] ...
ifdown [-ainmvf] ifaces...
Options:
-a De/configure all interfaces automatically -i FILE Use FILE for interface definitions -n Print out what would happen, but don't do it (note: doesn't disable mappings) -m Don't run any mappings -v Print out what would happen before doing it -f Force de/configuration
ifup [-ainmvf] IFACE...
Options:
-a De/configure all interfaces automatically -i FILE Use FILE for interface definitions -n Print out what would happen, but don't do it (note: doesn't disable mappings) -m Don't run any mappings -v Print out what would happen before doing it -f Force de/configuration
inetd [-fe] [-q N] [-R N] [CONFFILE]
Listen for network connections and launch programs
Options:
-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)
init
Init is the parent of all processes
insmod FILE [symbol=value]...
Load the specified kernel modules into the kernel
install [-cdDsp] [-o USER] [-g GRP] [-m MODE] [SOURCE]... DEST
Copy files and set attributes
Options:
-c Just copy (default) -d Create directories -D Create leading target directories -s Strip symbol table -p Preserve date -o USER Set ownership -g GRP Set group ownership -m MODE Set permissions
ip [OPTIONS] {address | route | link | tunnel | rule} {COMMAND}
ip [OPTIONS] OBJECT {COMMAND} where OBJECT := {address | route | link | tunnel | rule} OPTIONS := { -f[amily] { inet | inet6 | link } | -o[neline] }
ipaddr { {add|del} IFADDR dev STRING | {show|flush} | |
[dev STRING] [to PREFIX] } |
ipaddr {add|delete} IFADDR dev STRING ipaddr {show|flush} [dev STRING] [scope SCOPE-ID] [to PREFIX] [label PATTERN] IFADDR := PREFIX | ADDR peer PREFIX [broadcast ADDR] [anycast ADDR] [label STRING] [scope SCOPE-ID] SCOPE-ID := [host | link | global | NUMBER]
ipcrm [-MQS key] [-mqs id]
Upper-case options MQS remove an object by shmkey value. Lower-case options remove an object by shmid value.
Options:
-mM Remove memory segment after last detach -qQ Remove message queue -sS Remove semaphore
ipcs [[-smq] -i shmid] | [[-asmq] [-tcplu]]
-i Show specific resource Resource specification:
-m Shared memory segments -q Message queues -s Semaphore arrays -a All (default) Output format:
-t Time -c Creator -p Pid -l Limits -u Summary
iplink { set DEVICE { up | down | arp { on | off } | show [DEVICE] }
iplink set DEVICE { up | down | arp | multicast { on | off } | dynamic { on | off } | mtu MTU } iplink show [DEVICE]
iproute { list | flush | { add | del | change | append | | |
replace | monitor } ROUTE } |
iproute { list | flush } SELECTOR iproute get ADDRESS [from ADDRESS iif STRING] [oif STRING] [tos TOS] iproute { add | del | change | append | replace | monitor } ROUTE SELECTOR := [root PREFIX] [match PREFIX] [proto RTPROTO] ROUTE := [TYPE] PREFIX [tos TOS] [proto RTPROTO] [metric METRIC]
iprule {[list | add | del] RULE}
iprule [list | add | del] SELECTOR ACTION | |
SELECTOR := [from PREFIX] [to PREFIX] [tos TOS] [fwmark FWMARK] | |
[dev STRING] [pref NUMBER] | |
ACTION := [table TABLE_ID] [nat ADDRESS] | |
[prohibit | reject | unreachable] | |
[realms [SRCREALM/]DSTREALM] | |
TABLE_ID := [local | main | default | NUMBER] |
iptunnel { add | change | del | show } [NAME] | |
[mode { ipip | gre | sit }] | |
[remote ADDR] [local ADDR] [ttl TTL] |
iptunnel { add | change | del | show } [NAME] | |
[mode { ipip | gre | sit }] [remote ADDR] [local ADDR] | |
[[i|o]seq] [[i|o]key KEY] [[i|o]csum] | |
[ttl TTL] [tos TOS] [[no]pmtudisc] [dev PHYS_DEV] |
kill [-l] [-SIG] PID...
Send a signal (default: TERM) to given PIDs
Options:
-l List all signal names and numbers
killall [-l] [-q] [-SIG] PROCESS_NAME...
Send a signal (default: TERM) to given processes
Options:
-l List all signal names and numbers -q Don't complain if no processes were killed
killall5 [-l] [-SIG] [-o PID]...
Send a signal (default: TERM) to all processes outside current session
Options:
-l List all signal names and numbers -o PID Don't signal this PID
klogd [-c N] [-n]
Kernel logger
Options:
-c N Only messages with level < N are printed to console -n Run in foreground
last
Show listing of the last users that logged into the system
length STRING
Print STRING's length
less [-EMNmh~I?] [FILE]...
View FILE (or stdin) one screenful at a time
Options:
-E Quit once the end of a file is reached -M,-m Display status line with line numbers and percentage through the file -N Prefix line number to each line -I Ignore case in all searches -~ Suppress ~s displayed past the end of the file
ln [OPTIONS] TARGET... LINK|DIR
Create a link LINK or DIR/TARGET to the specified TARGET(s)
Options:
-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
loadfont < font
Load a console font from stdin
loadkmap < keymap
Load a binary keyboard translation table from stdin
logger [OPTIONS] [MESSAGE]
Write MESSAGE (or stdin) to syslog
Options:
-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 [-p] [-h HOST] [[-f] USER]
Begin a new session on the system
Options:
-f Don't authenticate (user already authenticated) -h Name of the remote host -p Preserve environment
logname
Print the name of the current user
losetup [-o OFS] LOOPDEV FILE - associate loop devices | |
losetup -d LOOPDEV - disassociate | |
losetup [-f] - show |
Options:
-o OFS Start OFS bytes into FILE -f Show first free loop device
ls [-1AacCdeFilnpLRrSsTtuvwxXhk] [FILE]...
List directory contents
Options:
-1 List in a single column -A Don't list . and .. -a Don't 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)
lsattr [-Radlv] [FILE]...
List file attributes on an ext2 fs
Options:
-R Recurse -a Don't hide entries starting with . -d List directory entries instead of contents -l List long flag names -v List the file's version/generation number
lsmod
List the currently loaded kernel modules
lspci [-mk]
List all PCI devices
-m Parseable output -k Show driver
lzmacat FILE
Uncompress to stdout
makedevs [-d device_table] rootdir
Create a range of special files as specified in a device table. Device table entries take the form of:
<type> <mode> <uid> <gid> <major> <minor> <start> <inc> <count> Where name is the file name, type can be one of: f Regular file d Directory c Character device b Block device p Fifo (named pipe) uid is the user id for the target file, gid is the group id for the target file. The rest of the entries (major, minor, etc) apply to to device special files. A '-' may be used for blank entries.
md5sum [OPTIONS] [FILE]... or: md5sum [OPTIONS] -c [FILE]
Print or check MD5 checksums
Options:
-c Check sums against given list -s Don't output anything, status code shows success -w Warn about improperly formatted checksum lines
mdev [-s]
-s Scan /sys and populate /dev during system boot
It can be run by kernel as a hotplug helper. To activate it: echo /sbin/mdev > /proc/sys/kernel/hotplug It uses /etc/mdev.conf with lines [-]DEVNAME UID:GID PERM [@|$|*PROG]
mesg [y|n]
Control write access to your terminal | ||
y | Allow write access to your terminal | |
n | Disallow write access to your terminal |
mkdir [OPTIONS] DIRECTORY...
Create DIRECTORY
Options:
-m Mode -p No error if exists; make parent directories as needed
mke2fs [-Fn] [-b BLK_SIZE] [-i INODE_RATIO] [-I INODE_SIZE] [-m RESERVED_PERCENT] [-L LABEL] BLOCKDEV [KBYTES]
-b BLK_SIZE Block size, bytes -F Force -i RATIO Max number of files is filesystem_size / RATIO -I BYTES Inode size (min 128) -L LBL Volume label -m PERCENT Percent of blocks to reserve for admin -n Dry run
mkfifo [OPTIONS] name
Create named pipe (identical to 'mknod name p')
Options:
-m MODE Mode (default a=rw)
mkfs.ext2 [-Fn] [-b BLK_SIZE] [-i INODE_RATIO] [-I INODE_SIZE] [-m RESERVED_PERCENT] [-L LABEL] BLOCKDEV [KBYTES]
-b BLK_SIZE Block size, bytes -F Force -i RATIO Max number of files is filesystem_size / RATIO -I BYTES Inode size (min 128) -L LBL Volume label -m PERCENT Percent of blocks to reserve for admin -n Dry run
mknod [OPTIONS] NAME TYPE MAJOR MINOR
Create a special file (block, character, or pipe)
Options:
-m Create the special file using the specified mode (default a=rw) TYPEs include:
b: Make a block device c or u: Make a character device p: Make a named pipe (MAJOR and MINOR are ignored)
mkswap [OPTIONS] BLOCKDEV [KBYTES]
Prepare BLOCKDEV to be used as swap partition
Options:
-L LBL Label
mktemp [-dt] [-p DIR] [TEMPLATE]
Create a temporary file with name based on TEMPLATE and print its name. TEMPLATE must end with XXXXXX (e.g. [/dir/]nameXXXXXX).
Options:
-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)
For -t or -p, directory is chosen as follows: $TMPDIR if set, else -p DIR, else /tmp
modprobe [-nqrsv] MODULE [symbol=value]...
Options:
-n Dry run -q Quiet -r Remove module (stacks) or do autoclean -s Report via syslog instead of stderr -v Verbose
more [FILE]...
View FILE (or stdin) one screenful at a time
mount [OPTIONS] [-o OPTS] DEVICE NODE
Mount a filesystem. Filesystem autodetection requires /proc.
Options:
-a Mount all filesystems in fstab -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
There are filesystem-specific -o flags.
mountpoint [-q] <[-dn] DIR | -x DEVICE>
Check if the directory is a mountpoint
Options:
-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
mt [-f device] opcode value
Control magnetic tape drive operation
Available Opcodes:
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 [OPTIONS] SOURCE DEST or: mv [OPTIONS] SOURCE... DIRECTORY
Rename SOURCE to DEST, or move SOURCE(s)
to DIRECTORY
Options:
-f Don't prompt before overwriting -i Interactive, prompt before overwrite
nameif [-s] [-c FILE] [{IFNAME MACADDR}]
Rename network interface while it in the down state
Options:
-c FILE Use configuration file (default: /etc/mactab) -s Use syslog (LOCAL0 facility) IFNAME MACADDR new_interface_name interface_mac_address
netstat [-laentuwxr]
Display networking information
Options:
-l Display listening server sockets -a Display all sockets (default: connected) -e Display other/more information -n Don't resolve names -t Tcp sockets -u Udp sockets -w Raw sockets -x Unix sockets -r Display routing table
nice [-n ADJUST] [PROG ARGS]
Run PROG with modified scheduling priority
Options:
-n ADJUST Adjust priority by ADJUST
nohup PROG ARGS
Run PROG immune to hangups, with output to a non-tty
nslookup [HOST] [SERVER]
Query the nameserver for the IP address of the given HOST optionally using a specified DNS server
od [-aBbcDdeFfHhIiLlOovXx] [-t TYPE] [FILE]
Write an unambiguous representation, octal bytes by default, of FILE (or stdin) to stdout
openvt [-c N] [-sw] [PROG ARGS]
Start PROG on a new virtual terminal
Options:
-c N Use specified VT -s Switch to the VT -w Wait for PROG to exit
passwd [OPTIONS] [USER]
Change USER's password. If no USER is specified, changes the password for the current user.
Options:
-a Algorithm to use for password (des, md5) -d Delete password for the account -l Lock (disable) account -u Unlock (re-enable) account
patch [OPTIONS] [ORIGFILE [PATCHFILE]]
-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't actually change files
pidof [OPTIONS] [NAME]...
List PIDs of all processes with names that match NAMEs
Options:
-s Show only one PID -o PID Omit given pid Use %PPID to omit pid of pidof's parent
ping [OPTIONS] HOST
Send ICMP ECHO_REQUEST packets to network hosts
Options:
-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
pivot_root NEW_ROOT PUT_OLD
Move the current root file system to PUT_OLD and make NEW_ROOT the new root file system
poweroff [-d DELAY] [-n] [-f]
Halt and shut off power
Options:
-d Delay interval for halting -n No call to sync() -f Force power off (don't go through init)
printenv [VARIABLE]...
Print environment VARIABLEs. If no VARIABLE specified, print all.
printf FORMAT [ARGUMENT]...
Format and print ARGUMENT(s)
according to FORMAT,
where FORMAT controls the output exactly as in C printf
ps
Report process status
Options:
-o col1,col2=header Select columns for display -T Show threads
pwd
Print the full filename of the current working directory
rdate [-sp] HOST
Get and possibly set the system date and time from a remote HOST
Options:
-s Set the system date and time (default) -p Print the date and time
readlink [-fnv] FILE
Display the value of a symlink
Options:
-f Canonicalize by following all symlinks -n Don't add newline -v Verbose
readprofile [OPTIONS]
Options:
-m mapfile (Default: /boot/System.map) -p profile (Default: /proc/profile) -M mult Set the profiling multiplier to mult -i Print only info about the sampling step -v Verbose -a Print all symbols, even if count is 0 -b Print individual histogram-bin counts -s Print individual counters within functions -r Reset all the counters (root only) -n Disable byte order auto-detection
realpath FILE...
Return the absolute pathnames of given FILE
reboot [-d DELAY] [-n] [-f]
Reboot the system
Options:
-d Delay interval for rebooting -n No call to sync() -f Force reboot (don't go through init)
renice {{-n INCREMENT} | PRIORITY} [[-p | -g | -u] ID...]
Change priority of running processes
Options:
-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
Reset the screen
resize
Resize the screen
rm [OPTIONS] FILE...
Remove (unlink) FILEs
Options:
-i Always prompt before removing -f Never prompt -R,-r Recurse
rmdir [OPTIONS] DIRECTORY...
Remove DIRECTORY if it is empty
Options:
-p Include parents
rmmod [OPTIONS] [MODULE]...
Unload the specified kernel modules from the kernel
Options:
-w Wait until the module is no longer used -f Force unloading -a Remove all unused modules (recursively)
route [{add|del|delete}]
Edit kernel routing tables
Options:
-n Don't resolve names -e Display other/more information -A inet{6} Select address family
run-parts [-t] [-a ARG] [-u MASK] DIRECTORY
Run a bunch of scripts in DIRECTORY
Options:
-t Print what would be run, but don't actually run anything -a ARG Pass ARG as argument for every program -u MASK Set the umask to MASK before running every program
runlevel [FILE]
Find the current and previous system runlevel
If no utmp FILE exists or if no runlevel record can be found, print ``unknown''
sed [-efinr] SED_CMD [FILE]...
Options:
-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
If no -e or -f, the first non-option argument is the sed command string. Remaining arguments are input files (stdin if none).
seq [-w] [-s SEP] [FIRST [INC]] LAST
Print numbers from FIRST to LAST, in steps of INC. FIRST, INC default to 1.
Options:
-w Pad to last with leading zeros -s SEP String separator
setarch personality PROG ARGS
Personality may be:
linux32 Set 32bit uname emulation linux64 Set 64bit uname emulation
setconsole [-r] [DEVICE]
Redirect system console output to DEVICE (default: /dev/tty)
Options:
-r Reset output to /dev/console
setkeycodes SCANCODE KEYCODE...
Set entries into the kernel's scancode-to-keycode map, allowing unusual keyboards to generate usable keycodes.
SCANCODE may be either xx or e0xx (hexadecimal), and KEYCODE is given in decimal.
setlogcons N
Redirect the kernel output to console N (0 for current)
setsid PROG ARGS
Run PROG in a new session. PROG will have no controlling terminal
and will not be affected by keyboard signals (Ctrl-C etc).
See setsid(2)
for details.
sha1sum [OPTIONS] [FILE]... or: sha1sum [OPTIONS] -c [FILE]
Print or check SHA1 checksums
Options:
-c Check sums against given list -s Don't output anything, status code shows success -w Warn about improperly formatted checksum lines
sha256sum [OPTIONS] [FILE]... or: sha256sum [OPTIONS] -c [FILE]
Print or check SHA256 checksums
Options:
-c Check sums against given list -s Don't output anything, status code shows success -w Warn about improperly formatted checksum lines
sha512sum [OPTIONS] [FILE]... or: sha512sum [OPTIONS] -c [FILE]
Print or check SHA512 checksums
Options:
-c Check sums against given list -s Don't output anything, status code shows success -w Warn about improperly formatted checksum lines
sleep N
Pause for N seconds
sort [-nrugMcszbdfimSTokt] [-o FILE] [-k start[.offset][opts][,end[.offset][opts]] [-t CHAR] [FILE]...
Sort lines of text
Options:
-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't sort ties alphabetically) -u Suppress duplicate lines -z Lines are terminated by NUL, not newline -mST Ignored for GNU compatibility
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,--user USERNAME|UID Match only this user's 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 [-afo] [-n LEN] [FILE]...
Display printable strings in a binary file
Options:
-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 [-a|g] [-F DEVICE] [SETTING]...
Without arguments, prints baud rate, line discipline, and deviations from stty sane
Options:
-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
su [OPTIONS] [-] [USERNAME]
Change user id or become root
Options:
-p,-m Preserve environment -c CMD Command to pass to 'sh -c' -s SH Shell to use instead of default shell
sulogin [-t N] [TTY]
Single user login
Options:
-t N Timeout
swapoff [-a] [DEVICE]
Stop swapping on DEVICE
Options:
-a Stop swapping on all swap devices
swapon [-a] [DEVICE]
Start swapping on DEVICE
Options:
-a Start swapping on all swap devices
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.
Options:
-c DEV Reopen stdio to DEV after switch
sync
Write all buffered blocks to disk
sysctl [OPTIONS] [VALUE]...
Configure kernel parameters at runtime
Options:
-n Don't print key names -e Don't 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 [OPTIONS]
System logging utility. This version of syslogd ignores /etc/syslog.conf
Options:
-n Run in foreground -O FILE Log to given file (default:/var/log/messages) -l N Set local log level -S Smaller logging output -s SIZE Max size (KB) before rotate (default:200KB, 0=off) -b N N rotated logs to keep (default:1, max=99, 0=purge) -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)
tail [OPTIONS] [FILE]...
Print last 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a header giving the file name.
Options:
-c N[kbm] Output last N bytes -n N[kbm] Print last N lines instead of last 10 -f Output data as the file grows -q Never output headers giving file names -s SEC Wait SEC seconds between reads with -f -v Always output headers giving file names
If the first character of N (bytes or lines) is a '+', output begins with the Nth item from the start of each file, otherwise, print the last N items in the file. N bytes may be suffixed by k (x1024), b (x512), or m (1024^2).
tar -[cxtvO] [-X FILE] [-f TARFILE] [-C DIR] [FILE]...
Create, extract, or list files from a tar file
Options:
c Create x Extract t List Archive format selection:
File selection:
f Name of TARFILE or "-" for stdin O Extract to stdout exclude File to exclude X File with names to exclude C Change to DIR before operation v Verbose
tee [OPTIONS] [FILE]...
Copy stdin to each FILE, and also to stdout
Options:
-a Append to the given FILEs, don't overwrite -i Ignore interrupt signals (SIGINT)
telnet [-a] [-l USER] HOST [PORT]
Connect to telnet server
Options:
-a Automatic login with $USER variable -l USER Automatic login as USER
telnetd [OPTIONS]
Handle incoming telnet connections
Options:
-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 -w SEC Inetd 'wait' mode, linger time SEC -S Log to syslog (implied by -i or without -F and -w)
test EXPRESSION ]
Check file types, compare values etc. Return a 0/1 exit code depending on logical value of EXPRESSION
tftp [OPTIONS] HOST [PORT]
Transfer a file from/to tftp server
Options:
-l FILE Local FILE -r FILE Remote FILE -g Get file -p Put file -b SIZE Transfer blocks of SIZE octets
time [OPTIONS] PROG ARGS
Run PROG, display resource usage when it exits
Options:
-v Verbose
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.
touch [-c] [-d DATE] FILE [FILE]...
Update the last-modified date on the given FILE[s]
Options:
-c Don't create files -d DT Date/time to use
tr [-cds] STRING1 [STRING2]
Translate, squeeze, or delete characters from stdin, writing to stdout
Options:
-c Take complement of STRING1 -d Delete input characters coded STRING1 -s Squeeze multiple output characters of STRING2 into one character
traceroute [-FIldnrv] [-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] |
Trace the route to HOST
Options:
-F Set the don't 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)
true
Return an exit code of TRUE (0)
tty
Print file name of stdin's terminal
Options:
-s Print nothing, only return exit status
tune2fs [-L LABEL] BLOCKDEV
Adjust filesystem options on ext[23] filesystems
udhcpc [-Cfbnqtvo] [-c CID] [-V VCLS] [-H HOSTNAME] [-i INTERFACE] | |
[-p pidfile] [-r IP] [-s script] [-O dhcp-option]... |
-V,--vendorclass=CLASSID Vendor class identifier -i,--interface=INTERFACE Interface to use (default eth0) -H,-h,--hostname=HOSTNAME Client hostname -c,--clientid=CLIENTID Client identifier -C,--clientid-none Suppress default client identifier -p,--pidfile=FILE Create pidfile -r,--request=IP IP address to request -s,--script=FILE Run FILE 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 (default 20) after failure -O,--request-option=OPT Request DHCP option OPT (cumulative) -o,--no-default-options Don't request any options (unless -O is also given) -f,--foreground Run in foreground -b,--background Background if lease is not immediately obtained -S,--syslog Log to syslog too -n,--now Exit with failure if lease is not immediately obtained -q,--quit Quit after obtaining lease -R,--release Release IP on quit -a,--arping Use arping to validate offered address
umount [OPTIONS] FILESYSTEM|DIRECTORY
Unmount file systems
Options:
-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 [-amnrspv]
Print system information
Options:
-a Print all -m The machine (hardware) type -n Hostname -r OS release -s OS name (default) -p Processor type -v OS version
uniq [-fscduw]... [INPUT [OUTPUT]]
Discard duplicate lines
Options:
-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 [OPTIONS] [FILE]
Convert FILE in-place from Unix to DOS format. When no file is given, use stdin/stdout.
Options:
-u dos2unix -d unix2dos
unlzma [OPTIONS] [FILE]...
Uncompress FILE (or stdin)
Options:
-c Write to stdout -f Force
unzip [-opts[modifiers]] file[.zip] [list] [-x xlist] [-d exdir]
Extract files from ZIP archives
Options:
-l List archive contents (with -q for short form) -n Never overwrite existing files (default) -o Overwrite files without prompting -p Send output to stdout -q Quiet -x Exclude these files -d Extract files into this directory
uptime
Display the time since the last boot
usleep N
Pause for N microseconds
uudecode [-o OUTFILE] [INFILE]
Uudecode a file Finds outfile name in uuencoded source unless -o is given
uuencode [-m] [INFILE] STORED_FILENAME
Uuencode a file to stdout
Options:
-m Use base64 encoding per RFC1521
vconfig COMMAND [OPTIONS]
Create and remove virtual ethernet devices
Options:
add [interface-name] [vlan_id] rem [vlan-name] set_flag [interface-name] [flag-num] [0 | 1] set_egress_map [vlan-name] [skb_priority] [vlan_qos] set_ingress_map [vlan-name] [skb_priority] [vlan_qos] set_name_type [name-type]
vi [OPTIONS] [FILE]...
Edit FILE
Options:
-c Initial command to run ($EXINIT also available) -R Read-only -H Short help regarding available features
vlock [OPTIONS]
Lock a virtual terminal. A password is required to unlock.
Options:
-a Lock all VTs
watch [-n SEC] [-t] PROG ARGS
Run PROG periodically
Options:
-n Loop period in seconds (default 2) -t Don't print header
watchdog [-t N[ms]] [-T N[ms]] [-F] DEV
Periodically write to watchdog device DEV
Options:
-T N Reboot after N seconds if not reset (default 60) -t N Reset every N seconds (default 30) -F Run in foreground
Use 500ms to specify period in milliseconds
wc [OPTIONS] [FILE]...
Print line, word, and byte counts for each FILE (or stdin), and a total line if more than one FILE is specified
Options:
-c Print the byte counts -l Print the newline counts -L Print the length of the longest line -w Print the word counts
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 |
Retrieve files via HTTP or FTP
Options:
-s Spider mode - only check file existence -c Continue retrieval of aborted transfer -q Quiet -P Set directory prefix to DIR -O Save to filename ('-' for stdout) -U Adjust 'User-Agent' field -Y Use proxy ('on' or 'off')
which [COMMAND]...
Locate a COMMAND
who [-a]
Show who is logged on
Options:
-a show all
whoami
Print the user name associated with the current effective user id
xargs [OPTIONS] [PROG ARGS]
Run PROG on every item given by stdin
Options:
-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 -x Exit if size is exceeded
yes [OPTIONS] [STRING]
Repeatedly output a line with STRING, or 'y'
zcat FILE
Uncompress 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 <vda.linux@googlemail.com>
The following people have contributed code to BusyBox whether they know it or not. If you have written code included in BusyBox, you should probably be listed here so you can obtain your bit of eternal glory. If you should be listed here, or the description of what you have done needs more detail, or is incorrect, please send in an update.
Emanuele Aina <emanuele.aina@tiscali.it> run-parts
Erik Andersen <andersen@codepoet.org>
Tons of new stuff, major rewrite of most of the core apps, tons of new apps as noted in header files. Lots of tedious effort writing these boring docs that nobody is going to actually read.
Laurence Anderson <l.d.anderson@warwick.ac.uk>
rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm
Jeff Angielski <jeff@theptrgroup.com>
ftpput, ftpget
Edward Betts <edward@debian.org>
expr, hostid, logname, whoami
John Beppu <beppu@codepoet.org>
du, nslookup, sort
Brian Candler <B.Candler@pobox.com>
tiny-ls(ls)
Randolph Chung <tausq@debian.org>
fbset, ping, hostname
Dave Cinege <dcinege@psychosis.com>
more(v2), makedevs, dutmp, modularization, auto links file, various fixes, Linux Router Project maintenance
Jordan Crouse <jordan@cosmicpenguin.net>
ipcalc
Magnus Damm <damm@opensource.se>
tftp client insmod powerpc support
Larry Doolittle <ldoolitt@recycle.lbl.gov>
pristine source directory compilation, lots of patches and fixes.
Glenn Engel <glenne@engel.org>
httpd
Gennady Feldman <gfeldman@gena01.com>
Sysklogd (single threaded syslogd, IPC Circular buffer support, logread), various fixes.
Karl M. Hegbloom <karlheg@debian.org>
cp_mv.c, the test suite, various fixes to utility.c, &c.
Daniel Jacobowitz <dan@debian.org>
mktemp.c
Matt Kraai <kraai@alumni.cmu.edu>
documentation, bugfixes, test suite
Stephan Linz <linz@li-pro.net>
ipcalc, Red Hat equivalence
John Lombardo <john@deltanet.com>
tr
Glenn McGrath <bug1@iinet.net.au>
Common unarchiving code and unarchiving applets, ifupdown, ftpgetput, nameif, sed, patch, fold, install, uudecode. Various bugfixes, review and apply numerous patches.
Manuel Novoa III <mjn3@codepoet.org>
cat, head, mkfifo, mknod, rmdir, sleep, tee, tty, uniq, usleep, wc, yes, mesg, vconfig, make_directory, parse_mode, dirname, mode_string, get_last_path_component, simplify_path, and a number trivial libbb routines
also bug fixes, partial rewrites, and size optimizations in ash, basename, cal, cmp, cp, df, du, echo, env, ln, logname, md5sum, mkdir, mv, realpath, rm, sort, tail, touch, uname, watch, arith, human_readable, interface, dutmp, ifconfig, route
Vladimir Oleynik <dzo@simtreas.ru>
cmdedit; xargs(current), httpd(current); ports: ash, crond, fdisk, inetd, stty, traceroute, top; locale, various fixes and irreconcilable critic of everything not perfect.
Bruce Perens <bruce@pixar.com>
Original author of BusyBox in 1995, 1996. Some of his code can still be found hiding here and there...
Tim Riker <Tim@Rikers.org>
bug fixes, member of fan club
Kent Robotti <robotti@metconnect.com>
reset, tons and tons of bug reports and patches.
Chip Rosenthal <chip@unicom.com>, <crosenth@covad.com>
wget - Contributed by permission of Covad Communications
Pavel Roskin <proski@gnu.org>
Lots of bugs fixes and patches.
Gyepi Sam <gyepi@praxis-sw.com>
Remote logging feature for syslogd
Linus Torvalds <torvalds@transmeta.com>
mkswap, fsck.minix, mkfs.minix
Mark Whitley <markw@codepoet.org>
grep, sed, cut, xargs(previous), style-guide, new-applet-HOWTO, bug fixes, etc.
Charles P. Wright <cpwright@villagenet.com>
gzip, mini-netcat(nc)
Enrique Zanardi <ezanardi@ull.es>
tarcat (since removed), loadkmap, various fixes, Debian maintenance
Tito Ragusa <farmatito@tiscali.it>
devfsd and size optimizations in strings, openvt and deallocvt.