Manpages

NAME

BusyBox - The Swiss Army Knife of Embedded Linux

SYNTAX

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

DESCRIPTION

BusyBox combines tiny versions of many common UNIX utilities into a single small executable. It provides minimalist replacements for most of the utilities you usually find in GNU coreutils, util-linux, etc. The utilities in BusyBox generally have fewer options than their full-featured GNU cousins; however, the options that are included provide the expected functionality and behave very much like their GNU counterparts.

BusyBox has been written with size-optimization and limited resources in mind. It is also extremely modular so you can easily include or exclude commands (or features) at compile time. This makes it easy to customize your embedded systems. To create a working system, just add /dev, /etc, and a Linux kernel. BusyBox provides a fairly complete POSIX environment for any small or embedded system.

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

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

USAGE

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

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

/bin/busybox ls

will also cause BusyBox to behave as ’ls’.

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

For example, entering

ln -s /bin/busybox ls
./ls

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

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

COMMON OPTIONS

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

COMMANDS

Currently available applets include:

[, [[, acpid, adjtimex, ar, arch, arp, arping, ascii, ash, awk,
base64, basename, bc, blkdiscard, blkid, blockdev, brctl, bunzip2,
bzcat, bzip2, cal, cat, chgrp, chmod, chown, chroot, chvt, clear,
cmp, cp, cpio, crc32, crond, crontab, cttyhack, cut, date, dc, dd,
deallocvt, depmod, devmem, df, diff, dirname, dmesg, dnsdomainname,
dos2unix, dpkg, dpkg-deb, du, dumpkmap, dumpleases, echo, ed, egrep,
env, expand, expr, factor, fallocate, false, fatattr, fdisk, fgrep,
find, findfs, fold, free, freeramdisk, fsfreeze, fstrim, ftpget,
ftpput, getopt, getty, grep, groups, gunzip, gzip, halt, head,
hexdump, hostid, hostname, httpd, hwclock, i2cdetect, i2cdump,
i2cget, i2cset, i2ctransfer, id, ifconfig, ifdown, ifup, init,
insmod, install, ionice, ip, ipcalc, kill, killall, klogd, last,
less, link, linux32, linux64, linuxrc, ln, loadfont, loadkmap,
logger, login, logname, logread, losetup, ls, lsmod, lsscsi, lzcat,
lzma, lzop, md5sum, mdev, microcom, mim, mkdir, mkdosfs, mke2fs,
mkfifo, mknod, mkpasswd, mkswap, mktemp, modinfo, modprobe, more,
mount, mt, mv, nameif, nbd-client, nc, netstat, nl, nologin, nproc,
nsenter, nslookup, nuke, od, openvt, partprobe, passwd, paste,
patch, pidof, ping, ping6, pivot_root, poweroff, printf, ps, pwd,
rdate, readlink, realpath, reboot, renice, reset, resume, rev, rm,
rmdir, rmmod, route, rpm, rpm2cpio, run-init, run-parts, sed, seq,
setkeycodes, setpriv, setsid, sh, sha1sum, sha256sum, sha3sum,
sha512sum, shred, shuf, sleep, sort, ssl_client, start-stop-daemon,
stat, strings, stty, su, sulogin, svc, svok, swapoff, swapon,
switch_root, sync, sysctl, syslogd, tac, tail, tar, taskset, tc,
tee, telnet, test, tftp, time, timeout, top, touch, tr, traceroute,
traceroute6, true, truncate, ts, tty, tunctl, ubirename, udhcpc,
udhcpc6, udhcpd, uevent, umount, uname, uncompress, unexpand, uniq,
unix2dos, unlink, unlzma, unshare, unxz, unzip, uptime, usleep,
uudecode, uuencode, vconfig, vi, w, watch, watchdog, wc, wget,
which, who, whoami, xargs, xxd, xz, xzcat, yes, zcat

COMMAND DESCRIPTIONS

acpid

acpid [-df] [-c CONFDIR] [-l LOGFILE] [-a ACTIONFILE] [-M MAPFILE] [-e PROC_EVENT_FILE] [-p PIDFILE]

Listen to ACPI events and spawn specific helpers on event arrival

-d Log to stderr, not log file (implies -f)
-f Run in foreground
-c DIR Config directory [/etc/acpi]
-e FILE /proc event file [/proc/acpi/event]
-l FILE Log file [/var/log/acpid.log]
-p FILE Pid file [/var/run/acpid.pid]
-a FILE Action file [/etc/acpid.conf]
-M FILE Map file [/etc/acpi.map]

Accept and ignore compatibility options -g -m -s -S -v

adjtimex

adjtimex [-q] [-o OFS] [-f FREQ] [-p TCONST] [-t TICK]

Read or set kernel time variables. See adjtimex(2)

-q Quiet
-o OFF Time offset, microseconds
-f FREQ Frequency adjust, integer kernel units (65536 is 1ppm)
-t TICK Microseconds per tick, usually 10000
(positive -t or -f values make clock run faster)
-p TCONST

Extract or list FILEs from an ar archive

x Extract
p Extract to stdout
t List
-o Restore mtime
-v Verbose

arch

arch

Print system architecture

Manipulate ARP cache

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

arping

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

Send ARP requests/replies

-f Quit on first ARP reply
-q Quiet
-b Keep broadcasting, don't go unicast
-D Exit with 1 if DST_IP replies
-U Unsolicited ARP mode, update your neighbors
-A ARP answer mode, update your neighbors
-c N Stop after sending N ARP requests
-w TIMEOUT Seconds to wait for ARP reply
-I IFACE Interface to use (default eth0)
-s SRC_IP Sender IP address
DST_IP Target IP address

Unix shell interpreter

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

base64

base64 [-d] [-w COL] [FILE]

Base64 encode or decode FILE to standard output

-d Decode data
-w COL Wrap lines at COL (default 76, 0 disables)

basename

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

Strip directory path and SUFFIX from FILE

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

Arbitrary precision calculator

-q Quiet
-l Load standard library
-s Be POSIX compatible
-w Warn if extensions are used

$BC_LINE_LENGTH changes output width

blkdiscard

blkdiscard [-o OFS] [-l LEN] [-s] DEVICE

Discard sectors on DEVICE

-o OFS Byte offset into device
-l LEN Number of bytes to discard
-s Perform a secure discard

blkid

blkid [BLOCKDEV]...

Print UUIDs of all filesystems

blockdev

blockdev OPTION BLOCKDEV

--setro Set ro
--setrw Set rw
--getro Get ro
--getss Get sector size
--getbsz Get block size
--setbsz BYTES Set block size
--getsz Get device size in 512-byte sectors
--getsize64 Get device size in bytes
--getra Get readahead in 512-byte sectors
--setra SECTORS Set readahead
--flushbufs Flush buffers
--rereadpt Reread partition table

brctl

brctl COMMAND [BRIDGE [ARGS]]

Manage ethernet bridges Commands:

addbr BRIDGE Create BRIDGE
delbr BRIDGE Delete BRIDGE
addif BRIDGE IFACE Add IFACE to BRIDGE
delif BRIDGE IFACE Delete IFACE from BRIDGE

bunzip2

bunzip2 [-cfk] [FILE]...

Decompress FILEs (or stdin)

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

bzcat

bzcat [FILE]...

Decompress to stdout

bzip2

bzip2 [-cfkdt123456789] [FILE]...

Compress FILEs (or stdin) with bzip2 algorithm

-1..9 Compression level
-d Decompress
-c Write to stdout
-f Force
-k Keep input files
-t Test integrity

Display a calendar

-j Use julian dates
-m Week starts on Monday
-y Display the entire year

Print FILEs to stdout

-n Number output lines
-b Number nonempty lines
-v Show nonprinting characters as ^x or M-x
-t ...and tabs as ^I
-e ...and end lines with $
-A Same as -vte

chgrp

chgrp [-RhLHPcvf]... GROUP FILE...

Change the group membership of FILEs to GROUP

-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)
-R Recurse
-c List changed files
-v Verbose
-f Hide errors

chmod

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

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

-R Recurse
-c List changed files
-v Verbose
-f Hide errors

chown

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

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

-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)
-R Recurse
-c List changed files
-v Verbose
-f Hide errors

chroot

chroot NEWROOT [PROG ARGS]

Run PROG with root directory set to NEWROOT

chvt

chvt N

Change the foreground virtual terminal to /dev/ttyN

clear

clear

Clear screen

Compare FILE1 with FILE2 (or stdin)

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

Copy SOURCEs to DEST

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

cpio

cpio [-dmvu] [-F FILE] [-R USER[:GRP]] [-H newc] [-tio] [EXTR_FILE]...

Extract (-i) or list (-t) files from a cpio archive, or take file list from stdin and create an archive (-o)

Main operation mode:

-t List
-i Extract EXTR_FILEs (or all)
-o Create (requires -H newc)
Options:
-H newc Archive format
-d Make leading directories
-m Restore mtime
-v Verbose
-u Overwrite
-F FILE Input (-t,-i,-p) or output (-o) file
-R USER[:GRP] Set owner of created files
-L Dereference symlinks
-0 NUL terminated input
--ignore-devno
--renumber-inodes

crc32

crc32 FILE...

Calculate CRC32 checksum of FILEs

crond

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

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

crontab

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

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

cttyhack

cttyhack [PROG ARGS]

setsid cttyhack sh

Print selected fields from FILEs to stdout

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

date

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

Display time (using +FMT), or set time

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

Recognized TIME formats:

@seconds_since_1970
hh:mm[:ss]
[YYYY.]MM.DD-hh:mm[:ss]
YYYY-MM-DD hh:mm[:ss]
[[[[[YY]YY]MM]DD]hh]mm[.ss]
'date TIME' form accepts MMDDhhmm[[YY]YY][.ss] instead

Tiny RPN calculator. Operations: Arithmetic: + - * / % ^ ~ - divide with remainder | - modular exponentiation v - square root p - print top of the stack without popping f - print entire stack k - pop the value and set precision i - pop the value and set input radix o - pop the value and set output radix Examples: dc -e’2 2 + p’ -> 4, dc -e’8 8 * 2 2 + / p’ -> 16

Copy a file with converting and formatting

if=FILE Read from FILE instead of stdin
of=FILE Write to FILE instead of stdout
bs=N Read and write N bytes at a time
ibs=N Read N bytes at a time
obs=N Write N bytes at a time
count=N Copy only N input blocks
skip=N Skip N input blocks
seek=N Skip N output blocks
conv=notrunc Don't truncate output file
conv=noerror Continue after read errors
conv=sync Pad blocks with zeros
conv=fsync Physically write data out before finishing
conv=swab Swap every pair of bytes
iflag=skip_bytes skip=N is in bytes
iflag=count_bytes count=N is in bytes
oflag=seek_bytes seek=N is in bytes
iflag=direct O_DIRECT input
oflag=direct O_DIRECT output
iflag=fullblock Read full blocks
oflag=append Open output in append mode
status=noxfer Suppress rate output
status=none Suppress all output

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

deallocvt

deallocvt [N]

Deallocate unused virtual terminal /dev/ttyN

depmod

depmod [-n] [-b BASE] [VERSION] [MODFILES]...

Generate modules.dep, alias, and symbols files

-b BASE Use BASE/lib/modules/VERSION
-n Dry run: print files to stdout

devmem

devmem ADDRESS [WIDTH [VALUE]]

Read/write from physical address

ADDRESS Address to act upon
WIDTH Width (8/16/...)
VALUE Data to be written

Print filesystem usage statistics

-P POSIX output format
-k 1024-byte blocks (default)
-m 1M-byte blocks
-h Human readable (e.g. 1K 243M 2G)
-T Print filesystem type
-t TYPE Print only mounts of this type
-a Show all filesystems
-i Inodes
-B SIZE Blocksize

diff

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.

-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

dirname FILENAME

Strip non-directory suffix from FILENAME

dmesg

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

Print or control the kernel ring buffer

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

dos2unix

dos2unix [-ud] [FILE]

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

-u dos2unix
-d unix2dos

dpkg

dpkg [-ilCPru] [-F OPT] PACKAGE

Install, remove and manage Debian packages

-i,--install Install the package
-l,--list List of installed packages
--configure Configure an unpackaged package
-P,--purge Purge all files of a package
-r,--remove Remove all but the configuration files for a package
--unpack Unpack a package, but don't configure it
--force-depends Ignore dependency problems
--force-confnew Overwrite existing config files when installing
--force-confold Keep old config files when installing

dpkg-deb

dpkg-deb [-cefxX] FILE [DIR]

Perform actions on Debian packages (.deb)

-c List files
-f Print control fields
-e Extract control files to DIR (default: ./DEBIAN)
-x Extract files to DIR (no default)
-X Verbose extract

Summarize disk space used for FILEs (or directories)

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

dumpkmap

dumpkmap > keymap

Print a binary keyboard translation table to stdout

dumpleases

dumpleases [-r|-a] [-d] [-f LEASEFILE]

Display DHCP leases granted by udhcpd

-f FILE Lease file
-r Show remaining time
-a Show expiration time
-d Show time in seconds

echo

echo [-neE] [ARG]...

Print ARGs to stdout

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

Print current environment or run PROG after setting up environment

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

expand

expand [-i] [-t N] [FILE]...

Convert tabs to spaces, writing to stdout

-i Don't convert tabs after non blanks
-t Tabstops every N chars

expr

expr EXPRESSION

Print the value of EXPRESSION

EXPRESSION may be:

ARG1 | ARG2 ARG1 if it is neither null nor 0, otherwise ARG2
ARG1 & ARG2 ARG1 if neither argument is null or 0, otherwise 0
ARG1 < ARG2 1 if ARG1 is less than ARG2, else 0. Similarly:
ARG1 <= ARG2
ARG1 = ARG2
ARG1 != ARG2
ARG1 >= ARG2
ARG1 > ARG2
ARG1 + ARG2 Sum of ARG1 and ARG2. Similarly:
ARG1 - ARG2
ARG1 * ARG2
ARG1 / ARG2
ARG1 % ARG2
STRING : REGEXP Anchored pattern match of REGEXP in STRING
match STRING REGEXP Same as STRING : REGEXP
substr STRING POS LEN Substring of STRING, POS counts from 1
index STRING CHARS Index in STRING where any CHARS is found, or 0
length STRING Length of STRING
quote TOKEN Interpret TOKEN as a string, even if
it is a keyword like 'match' or an
operator like '/'
(EXPRESSION) Value of EXPRESSION

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

factor

factor [NUMBER]...

Print prime factors

fallocate

fallocate [-o OFS] -l LEN FILE

Preallocate space for FILE

-o OFS Offset of range
-l LEN Length of range

fatattr

fatattr [-+rhsvda] FILE...

Change file attributes on FAT filesystem

- Clear attributes
+ Set attributes
r Read only
h Hidden
s System
v Volume label
d Directory
a Archive

fdisk

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

Change partition table

-u Start and End are in sectors (instead of cylinders)
-l Show partition table for each DISK, then exit
-b 2048 (for certain MO disks) use 2048-byte sectors
-C CYLINDERS Set number of cylinders/heads/sectors
-H HEADS Typically 255
-S SECTORS Typically 63

find

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

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

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

Actions:

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

findfs

findfs LABEL=label or UUID=uuid

Find a filesystem device based on a label or UUID

fold

fold [-bs] [-w WIDTH] [FILE]...

Wrap input lines in FILEs (or stdin), writing to stdout

-b Count bytes rather than columns
-s Break at spaces
-w Use WIDTH columns instead of 80

free

free [-bkmgh]

Display free and used memory

freeramdisk

freeramdisk DEVICE

Free all memory used by the specified ramdisk

fsfreeze

fsfreeze --[un]freeze MOUNTPOINT

Flush and halt writes to MOUNTPOINT

fstrim

fstrim [OPTIONS] MOUNTPOINT

-o OFFSET Offset in bytes to discard from
-l LEN Bytes to discard
-m MIN Minimum extent length
-v Print number of discarded bytes

ftpget

ftpget [OPTIONS] HOST [LOCAL_FILE] REMOTE_FILE

Download a file via FTP

-c Continue previous transfer
-v Verbose
-u USER Username
-p PASS Password
-P PORT

ftpput

ftpput [OPTIONS] HOST [REMOTE_FILE] LOCAL_FILE

Upload a file to a FTP server

-v Verbose
-u USER Username
-p PASS Password
-P PORT

getopt

getopt [OPTIONS] [--] OPTSTRING PARAMS

-a Allow long options starting with single -
-l LOPT[,...] Long options to recognize
-n PROGNAME The name under which errors are reported
-o OPTSTRING Short options to recognize
-q No error messages on unrecognized options
-Q No normal output
-s SHELL Set shell quoting conventions
-T Version test (exits with 4)
-u Don't quote output

Example:

getty

getty [OPTIONS] BAUD_RATE[,BAUD_RATE]... TTY [TERMTYPE]

Open TTY, prompt for login name, then invoke /bin/login

-h Enable hardware RTS/CTS flow control
-L Set CLOCAL (ignore Carrier Detect state)
-m Get baud rate from modem's CONNECT status message
-n Don't prompt for login name
-w Wait for CR or LF before sending /etc/issue
-i Don't display /etc/issue
-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 login name is read
-I INITSTR Send INITSTR before anything else
-H HOST Log HOST into the utmp file as the hostname

BAUD_RATE of 0 leaves it unchanged

grep

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

Search for PATTERN in FILEs (or stdin)

-H Add 'filename:' prefix
-h Do not add 'filename:' prefix
-n Add 'line_no:' prefix
-l Show only names of files that match
-L Show only names of files that don't match
-c Show only count of matching lines
-o Show only the matching part of line
-q Quiet. Return 0 if PATTERN is found, 1 otherwise
-v Select non-matching lines
-s Suppress open and read errors
-r Recurse
-R Recurse and dereference symlinks
-i Ignore case
-w Match whole words only
-x Match whole lines only
-F PATTERN is a literal (not regexp)
-E PATTERN is an extended regexp
-z NUL terminated input
-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

groups

groups [USER]

Print the groups USER is in

gunzip

gunzip [-cfkt] [FILE]...

Decompress FILEs (or stdin)

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

gzip

gzip [-cfkdt] [FILE]...

Compress FILEs (or stdin)

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

halt

halt [-d DELAY] [-nfw]

Halt the system

-d SEC Delay interval
-n Do not sync
-f Force (don't go through init)
-w Only write a wtmp record

head

head [OPTIONS] [FILE]...

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

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

hexdump

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

Display FILEs (or stdin) in a user specified format

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

hostid

hostid

Print out a unique 32-bit identifier for the machine

hostname

hostname [-sidf] [HOSTNAME | -F FILE]

Show or set hostname or DNS domain name

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

httpd

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

-i Inetd mode
-f Run in foreground
-v[v] Verbose
-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 .)
-c FILE Configuration file (default {/etc,HOME}/httpd.conf)
-m STRING MD5 crypt STRING
-e STRING HTML encode STRING
-d STRING URL decode STRING

hwclock

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

Show or set hardware clock (RTC)

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

i2cdetect

i2cdetect -l | -F I2CBUS | [-ya] [-q|-r] I2CBUS [FIRST LAST]

Detect I2C chips

-l List installed buses
-F BUS# List functionalities on this bus
-y Disable interactive mode
-a Force scanning of non-regular addresses
-q Use smbus quick write commands for probing (default)
-r Use smbus read byte commands for probing
FIRST and LAST limit probing range

i2cdump

i2cdump [-fy] [-r FIRST-LAST] BUS ADDR [MODE]

Examine I2C registers

I2CBUS I2C bus number
ADDRESS 0x03-0x77
MODE is:
b Byte (default)
w Word
W Word on even register addresses
i I2C block
s SMBus block
c Consecutive byte
Append p for SMBus PEC
-f Force access
-y Disable interactive mode
-r Limit the number of registers being accessed

i2cget

i2cget [-fy] BUS CHIP-ADDRESS [DATA-ADDRESS [MODE]]

Read from I2C/SMBus chip registers

I2CBUS I2C bus number
ADDRESS 0x03-0x77
MODE is:
b Read byte data (default)
w Read word data
c Write byte/read byte
Append p for SMBus PEC
-f Force access
-y Disable interactive mode

i2cset

i2cset [-fy] [-m MASK] BUS CHIP-ADDRESS DATA-ADDRESS [VALUE] ... [MODE]

Set I2C registers

I2CBUS I2C bus number
ADDRESS 0x03-0x77
MODE is:
c Byte, no value
b Byte data (default)
w Word data
i I2C block data
s SMBus block data
Append p for SMBus PEC
-f Force access
-y Disable interactive mode
-r Read back and compare the result
-m MASK Mask specifying which bits to write

i2ctransfer

i2ctransfer [-fay] I2CBUS { rLENGTH[@ADDR] | wLENGTH[@ADDR] DATA...}...

Read/write I2C data in one transfer

-f Force access to busy addresses
-a Force access to non-regular addresses
-y Disable interactive mode

Print information about USER or the current user

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

ifconfig

ifconfig [-a] [IFACE] [ADDRESS]

Configure a network interface

[add ADDRESS[/PREFIXLEN]]
[del ADDRESS[/PREFIXLEN]]
[[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]]
[netmask ADDRESS] [dstaddr ADDRESS]
[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

ifdown [-nmvf] [-i FILE] -a | IFACE...

-a Deconfigure all interfaces
-i FILE Use FILE instead of /etc/network/interfaces
-n Dry run
(note: doesn't disable mappings)
-m Don't run any mappings
-v Print out what would happen before doing it
-f Force

ifup

ifup [-nmvf] [-i FILE] -a | IFACE...

-a Configure all interfaces
-i FILE Use FILE instead of /etc/network/interfaces
-n Dry run
(note: doesn't disable mappings)
-m Don't run any mappings
-v Print out what would happen before doing it
-f Force

init

init

Init is the first process started during boot. It never exits. It (re)spawns children according to /etc/inittab. Signals:

HUP: reload /etc/inittab TSTP: stop respawning until CONT QUIT: re-exec another init USR1/TERM/USR2/INT: run halt/reboot/poweroff/Ctrl-Alt-Del script

insmod

insmod FILE [SYMBOL=VALUE]...

Load kernel module

install

install [-cdDsp] [-o USER] [-g GRP] [-m MODE] [-t DIR] [SOURCE]... DEST

Copy files and set attributes

-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
-t DIR Install to DIR

ionice

ionice [-c 1-3] [-n 0-7] [-t] { -p PID | PROG ARGS }

Change I/O priority and class

-c N Class. 1:realtime 2:best-effort 3:idle
-n N Priority
-t Ignore errors

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

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

ipcalc

ipcalc [-bnmphs] ADDRESS[/PREFIX] [NETMASK]

Calculate and display network settings from IP address

-b Broadcast address
-n Network address
-m Default netmask for IP
-p Prefix for IP/NETMASK
-h Resolved host name
-s No error messages

kill

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

Send a signal (default: TERM) to given PIDs

-l List all signal names and numbers

killall

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

Send a signal (default: TERM) to given processes

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

klogd

klogd [-c N] [-n]

Log kernel messages to syslog

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

last

last

Show listing of the last users that logged into the system

less

less [-EFIMmNSRh~] [FILE]...

View FILE (or stdin) one screenful at a time

-E Quit once the end of a file is reached
-F Quit if entire file fits on first screen
-I Ignore case in all searches
-M,-m Display status line with line numbers
and percentage through the file
-N Prefix line number to each line
-S Truncate long lines
-R Remove color escape codes in input
-~ Suppress ~s displayed past EOF

link

link FILE LINK

Create hard LINK to FILE

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

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

loadfont

loadfont < font

Load a console font from stdin

loadkmap

loadkmap < keymap

Load a binary keyboard translation table from stdin

logger

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

Write MESSAGE (or stdin) to syslog

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

login

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

Begin a new session on the system

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

logname

logname

Print the name of the current user

logread

logread [-fF]

Show messages in syslogd’s circular buffer

-f Output data as log grows
-F Same as -f, but dump buffer first

losetup

-o OFS Start OFS bytes into FILE
-P Scan for partitions
-r Read-only
-f Show/use next free loop device

List directory contents

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

lsmod

lsmod

List loaded kernel modules

lzcat

lzcat [FILE]...

Decompress to stdout

lzma

lzma -d [-cfk] [FILE]...

Decompress FILEs (or stdin)

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

lzop

lzop [-cfUvd123456789CF] [FILE]...

-1..9 Compression level
-d Decompress
-c Write to stdout
-f Force
-U Delete input files
-v Verbose
-F Don't store or verify checksum
-C Also write checksum of compressed block

md5sum

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

Print or check MD5 checksums

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

mdev

mdev [-vS] { [-s] | [-df] }

-v Verbose
-S Log to syslog too
-s Scan /sys and populate /dev
-d Daemon, listen on netlink
-f Run in foreground

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

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

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

microcom

microcom [-d DELAY_MS] [-t TIMEOUT_MS ] [-s SPEED] [-X] TTY

Copy bytes from stdin to TTY and from TTY to stdout

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

Run a script from a Makefile-like specification file

-f FILE Spec file (default Mimfile)

mkdir

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

Create DIRECTORY

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

mkdosfs

mkdosfs [-v] [-n LABEL] BLOCKDEV [KBYTES]

Make a FAT32 filesystem

-v Verbose
-n LBL Volume label

mke2fs

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

mkfifo [-m MODE] NAME

Create named pipe

-m MODE Mode (default a=rw)

mknod

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

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

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

mkpasswd

mkpasswd [-P FD] [-m TYPE] [-S SALT] [PASSWORD] [SALT]

Print crypt(3) hashed PASSWORD

-P N Read password from fd N
-m TYPE des,md5,sha256/512 (default )
-S SALT

mkswap

mkswap [-L LBL] BLOCKDEV [KBYTES]

Prepare BLOCKDEV to be used as swap partition

-L LBL Label

mktemp

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

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

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

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

modinfo

modinfo [-adlpn0] [-F keyword] MODULE

-a Shortcut for '-F author'
-d Shortcut for '-F description'
-l Shortcut for '-F license'
-p Shortcut for '-F parm'
-F keyword Keyword to look for
-0 NUL terminated output

modprobe

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

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

more

more [FILE]...

View FILE (or stdin) one screenful at a time

mount

mount [OPTIONS] [-o OPT] DEVICE NODE

Mount a filesystem. Filesystem autodetection requires /proc.

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

There are filesystem-specific -o flags.

Control magnetic tape drive operation

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

Rename SOURCE to DEST, or move SOURCEs to DIRECTORY

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

nameif

nameif [-s] [-c FILE] [IFNAME HWADDR]...

Rename network interface while it in the down state. The device with address HWADDR is renamed to IFNAME.

-c FILE Configuration file (default: /etc/mactab)
-s Log to syslog

nbd-client

nbd-client { [-b BLKSIZE] [-N NAME] [-t SEC] [-p] HOST [PORT] | -d } BLOCKDEV

Connect to HOST and provide network block device on BLOCKDEV

Open a pipe to IP:PORT or FILE

-l Listen mode, for inbound connects
(use -ll with -e for persistent server)
-p PORT Local port
-w SEC Connect timeout
-i SEC Delay interval for lines sent
-f FILE Use file (ala /dev/ttyS0) instead of network
-e PROG Run PROG after connect

netstat

netstat [-ral] [-tuwx] [-en]

Display networking information

-r Routing table
-a All sockets
-l Listening sockets
Else: connected sockets
-t TCP sockets
-u UDP sockets
-w Raw sockets
-x Unix sockets
Else: all socket types
-e Other/more information
-n Don't resolve names

Write FILEs to standard output with line numbers added

-b STYLE Which lines to number - a: all, t: nonempty, n: none
-i N Line number increment
-s STRING Use STRING as line number separator
-v N Start from N
-w N Width of line numbers

nologin

nologin

Politely refuse a login

nproc

nproc [--all] [--ignore=N]

Print number of available CPUs

--all Number of installed CPUs
--ignore=N Exclude N CPUs

nsenter

nsenter [OPTIONS] [PROG ARGS]

-t PID Target process to get namespaces from
-m[FILE] Enter mount namespace
-u[FILE] Enter UTS namespace (hostname etc)
-i[FILE] Enter System V IPC namespace
-n[FILE] Enter network namespace
-p[FILE] Enter pid namespace
-U[FILE] Enter user namespace
-S UID Set uid in entered namespace
-G GID Set gid in entered namespace
--preserve-credentials Don't touch uids or gids
-r[DIR] Set root directory
-w[DIR] Set working directory
-F Don't fork before exec'ing PROG

nslookup

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

Query DNS about HOST

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

nuke

nuke DIR...

Remove DIRs

Print FILEs (or stdin) unambiguously, as octal bytes by default

openvt

openvt [-c N] [-sw] [PROG ARGS]

Start PROG on a new virtual terminal

-c N Use specified VT
-s Switch to the VT
-w Wait for PROG to exit

partprobe

partprobe DEVICE...

Ask kernel to rescan partition table

passwd

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

Change USER’s password (default: current user)

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

paste

paste [-d LIST] [-s] [FILE]...

Paste lines from each input file, separated with tab

-d LIST Use delimiters from LIST, not tab
-s Serial: one file at a time

patch

patch [-RNE] [-p N] [-i DIFF] [ORIGFILE [PATCHFILE]]

-p N Strip N leading components from file names
-i DIFF Read DIFF instead of stdin
-R Reverse patch
-N Ignore already applied patches
-E Remove output files if they become empty
--dry-run Don't actually change files

pidof

pidof [NAME]...

List PIDs of all processes with names that match NAMEs

ping

ping [OPTIONS] HOST

Send ICMP ECHO_REQUESTs to HOST

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

ping6

ping6 [OPTIONS] HOST

Send ICMP ECHO_REQUESTs to HOST

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

pivot_root

pivot_root NEW_ROOT PUT_OLD

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

poweroff

poweroff [-d DELAY] [-nf]

Halt and shut off power

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

printf

printf FORMAT [ARG]...

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

Show list of processes

-o COL1,COL2=HEADER Select columns for display
-T Show threads

Print the full filename of the current working directory

rdate

rdate [-s/-p] HOST

Set and print time from HOST using RFC 868

-s Only set system time
-p Only print time

readlink

readlink [-fnv] FILE

Display the value of a symlink

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

realpath

realpath FILE...

Print absolute pathnames of FILEs

reboot

reboot [-d DELAY] [-nf]

Reboot the system

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

renice

renice [-n] PRIORITY [[-p|g|u] ID...]...

Change scheduling priority of a running process

-n Add PRIORITY to current nice value
Without -n, nice value is set to PRIORITY
-p Process ids (default)
-g Process group ids
-u Process user names

reset

reset

Reset terminal (ESC codes) and termios (signals, buffering, echo)

resume

resume BLOCKDEV [OFFSET]

Restore system state from ’suspend-to-disk’ data in BLOCKDEV

Reverse lines of FILE

Remove (unlink) FILEs

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

rmdir

rmdir [-p] DIRECTORY...

Remove DIRECTORY if it is empty

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

rmmod

rmmod [-wfa] [MODULE]...

Unload kernel modules

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

route

Show or edit kernel routing tables

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

Manipulate RPM packages

Commands:

-i Install package
-qp Query package
-qpi Show information
-qpl List contents
-qpd List documents
-qpc List config files

rpm2cpio

rpm2cpio PACKAGE.rpm

Output a cpio archive of the rpm file

run-init

run-init [-d CAP,CAP...] [-n] [-c CONSOLE_DEV] NEW_ROOT NEW_INIT [ARGS]

Free initramfs and switch to another root fs:

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

-c DEV Reopen stdio to DEV after switch
-d CAPS Drop capabilities
-n Dry run

run-parts

run-parts [-a ARG]... [-u UMASK] [--reverse] [--test] [--exit-on-error] DIRECTORY

Run a bunch of scripts in DIRECTORY

-a ARG Pass ARG as argument to scripts
-u UMASK Set UMASK before running scripts
--reverse Reverse execution order
--test Dry run
--exit-on-error Exit if a script exits with non-zero

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

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

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

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

setkeycodes

setkeycodes { SCANCODE KEYCODE }...

Modify kernel’s scancode-to-keycode map, allowing unusual keyboards to generate usable keycodes.

SCANCODE is either xx or e0xx (hexadecimal), KEYCODE is decimal.

setpriv

setpriv [OPTIONS] PROG ARGS

Run PROG with different privilege settings

setsid

setsid [-c] PROG ARGS

Run PROG in a new session. PROG will have no controlling terminal and will not be affected by keyboard signals (^C etc).

-c Set controlling terminal to stdin

Unix shell interpreter

sha1sum

sha1sum [-c[sw]] [FILE]...

Print or check SHA1 checksums

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

sha256sum

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

Print or check SHA256 checksums

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

sha3sum

sha3sum [-c[sw]] [-a BITS] [FILE]...

Print or check SHA3 checksums

-c Check sums against list in FILEs
-s Don't output anything, status code shows success
-w Warn about improperly formatted checksum lines
-a BITS 224 (default), 256, 384, 512

sha512sum

sha512sum [-c[sw]] [FILE]...

Print or check SHA512 checksums

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

shred

shred [-fuz] [-n N] [-s SIZE] FILE...

Overwrite/delete FILEs

-f Chmod to ensure writability
-s SIZE Size to write
-n N Overwrite N times (default 3)
-z Final overwrite with zeros
-u Remove file

shuf

shuf [-n NUM] [-o FILE] [-z] [FILE | -e [ARG...] | -i L-H]

Randomly permute lines

-n NUM Output at most NUM lines
-o FILE Write to FILE, not standard output
-z NUL terminated output
-e Treat ARGs as lines
-i L-H Treat numbers L-H as lines

sleep

sleep [N]...

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

sort

sort [-nrughMcszbdfiokt] [-o FILE] [-k START[.OFS][OPTS][,END[.OFS][OPTS]] [-t CHAR] [FILE]...

Sort lines of text

-o FILE Output to FILE
-c Check whether input is sorted
-b Ignore leading blanks
-f Ignore case
-i Ignore unprintable characters
-d Dictionary order (blank or alphanumeric only)
-n Sort numbers
-g General numerical sort
-h Sort human readable numbers (2K 1G)
-M Sort month
-V Sort version
-t CHAR Field separator
-k N[,M] Sort by Nth field
-r Reverse sort order
-s Stable (don't sort ties alphabetically)
-u Suppress duplicate lines
-z NUL terminated input and output

ssl_client

ssl_client [-e] -s FD [-r FD] [-n SNI]

start-stop-daemon

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

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

Process matching:

-u USERNAME|UID Match only this user's processes
-n NAME Match processes with NAME
in comm field in /proc/PID/stat
-x EXECUTABLE Match processes with this command
in /proc/PID/cmdline
-p FILE Match a process with PID from FILE
All specified conditions must match
-S only:
-x EXECUTABLE Program to run
-a NAME Zeroth argument
-b Background
-N N Change nice level
-c USER[:[GRP]] Change user/group
-m Write PID to pidfile specified by -p
-K only:
-s SIG Signal to send
-t Match only, exit with 0 if found
Other:
-o Exit with status 0 if nothing is done
-v Verbose
-q Quiet

stat

stat [-ltf] [-c FMT] FILE...

Display file (default) or filesystem status

-c FMT Use the specified format
-f Display filesystem status
-L Follow links
-t Terse display

FMT sequences for files:

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

FMT sequences for file systems:

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

strings

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

Display printable strings in a binary file

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

stty

stty [-a|g] [-F DEVICE] [SETTING]...

Without arguments, prints baud rate, line discipline, and deviations from stty sane

-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

Run shell under USER (by default, root)

-,-l Clear environment, go to home dir, run shell as login shell
-p,-m Do not set new $HOME, $SHELL, $USER, $LOGNAME
-c CMD Command to pass to 'sh -c'
-s SH Shell to use instead of user's default

sulogin

sulogin [-t N] [TTY]

Single user login

-p Start a login shell
-t SEC Timeout

Control services monitored by runsv supervisor

-u If service is not running, start it; restart if it stops
-d If service is running, send TERM+CONT signals; do not restart it
-o Once: if service is not running, start it; do not restart it
-pchaitk Send STOP, CONT, HUP, ALRM, INT, TERM, KILL signal to service
-x Exit: runsv will exit as soon as the service is down

svok

svok SERVICE_DIR

Check whether runsv supervisor is running. Exit code is 0 if it does, 100 if it does not, 111 (with error message) if SERVICE_DIR does not exist.

swapoff

swapoff [-a] [DEVICE]

Stop swapping on DEVICE

-a Stop swapping on all swap devices

swapon

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

Start swapping on DEVICE

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

switch_root

switch_root [-c CONSOLE_DEV] NEW_ROOT NEW_INIT [ARGS]

Free initramfs and switch to another root fs:

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

-c DEV Reopen stdio to DEV after switch

sync

sync [-df] [FILE]...

sysctl

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

Show/set kernel parameters

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

syslogd

syslogd [OPTIONS]

System logging utility

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

Concatenate FILEs and print them in reverse

tail

tail [OPTIONS] [FILE]...

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

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

Create, extract, or list files from a tar file

c Create
x Extract
t List
-f FILE Name of TARFILE ('-' for stdin/out)
-C DIR Change to DIR before operation
-v Verbose
-O Extract to stdout
-m Don't restore mtime
-o Don't restore user:group
-k Don't replace existing files
-Z (De)compress using compress
-z (De)compress using gzip
-J (De)compress using xz
-j (De)compress using bzip2
--lzma (De)compress using lzma
-a (De)compress based on extension
-h Follow symlinks
--overwrite Replace existing files
--strip-components NUM NUM of leading components to strip
--no-recursion Don't descend in directories
--numeric-owner Use numeric user:group
--no-same-permissions Don't restore access permissions
--to-command COMMAND Pipe files to COMMAND

taskset

taskset [-ap] [HEXMASK | -c LIST] { PID | PROG ARGS }

Set or get CPU affinity

-p Operate on PID
-a Operate on all threads
-c Affinity is a list, not mask

OBJECT: qdisc|class|filter CMD: add|del|change|replace|show

qdisc [handle QHANDLE] [root|ingress|parent CLASSID] [[QDISC_KIND] [help|OPTIONS]] QDISC_KIND := [p|b]fifo|tbf|prio|red|etc. qdisc show [dev STRING] [ingress] class [classid CLASSID] [root|parent CLASSID] [[QDISC_KIND] [help|OPTIONS] ] class show [ dev STRING ] [root|parent CLASSID] filter [pref PRIO] [protocol PROTO] [root|classid CLASSID] [handle FILTERID] [[FILTER_TYPE] [help|OPTIONS]] filter show [dev STRING] [root|parent CLASSID]

Copy stdin to each FILE, and also to stdout

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

telnet

telnet [-a] [-l USER] HOST [PORT]

Connect to telnet server

-a Automatic login with $USER variable
-l USER Automatic login as USER

tftp

tftp [OPTIONS] HOST [PORT]

Transfer a file from/to tftp server

-l FILE Local FILE
-r FILE Remote FILE
-g Get file
-p Put file
-b SIZE Transfer blocks in bytes

time

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

Run PROG, display resource usage when it exits

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

timeout

timeout [-s SIG] [-k KILL_SECS] SECS PROG ARGS

Run PROG. Send SIG to it if it is not gone in SECS seconds. Default SIG: TERM.If it still exists in KILL_SECS seconds, send KILL.

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

N/M/P/T: sort by pid/mem/cpu/time
R: reverse sort
H: toggle threads
Q,^C: exit
Options:
-b Batch mode
-n N Exit after N iterations
-d SEC Delay between updates
-H Show threads

touch

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

Update mtime of FILEs

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

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

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

traceroute

Trace the route to HOST

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

traceroute6

Trace the route to HOST

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

truncate

truncate [-c] -s SIZE FILE...

Truncate FILEs to SIZE

-c Do not create files
-s SIZE

Pipe stdin to stdout, add timestamp to each line

-s Time since start
-i Time since previous line

Print file name of stdin’s terminal

-s Print nothing, only return exit status

tunctl

tunctl [-f DEVICE] [-t NAME | -d NAME]

Create or delete TUN/TAP interfaces

-f DEV TUN device (default /dev/net/tun)
-t NAME Create iface (default: tapN)
-d NAME Delete iface

ubirename

ubirename UBI_DEVICE OLD_VOLNAME NEW_VOLNAME [OLD2 NEW2]...

Rename UBI volumes on UBI_DEVICE

udhcpc

-i IFACE Interface to use (default eth0)
-s PROG Run PROG at DHCP events (default /etc/udhcpc/default.script)
-p FILE Create pidfile
-B Request broadcast replies
-t N Send up to N discover packets (default 3)
-T SEC Pause between packets (default 3)
-A SEC Wait if lease is not obtained (default 20)
-b Background if lease is not obtained
-n Exit if lease is not obtained
-q Exit after obtaining lease
-R Release IP on exit
-f Run in foreground
-S Log to syslog too
-a[MSEC] Validate offered address with ARP ping
-r IP Request this IP address
-o Don't request any options (unless -O is given)
-O OPT Request option OPT from server (cumulative)
-x OPT:VAL Include option OPT in sent packets (cumulative)
Examples of string, numeric, and hex byte opts:
-x hostname:bbox - option 12
-x lease:3600 - option 51 (lease time)
-x 0x3d:0100BEEFC0FFEE - option 61 (client id)
-x 14:'"dumpfile"' - option 14 (shell-quoted)
-F NAME Ask server to update DNS mapping for NAME
-V VENDOR Vendor identifier (default 'udhcp VERSION')
-C Don't send MAC as client identifier
Signals:
USR1 Renew lease
USR2 Release lease

udhcpc6

-i IFACE Interface to use (default eth0)
-p FILE Create pidfile
-s PROG Run PROG at DHCP events (default /etc/udhcpc/default6.script)
-B Request broadcast replies
-t N Send up to N discover packets
-T SEC Pause between packets (default 3)
-A SEC Wait if lease is not obtained (default 20)
-b Background if lease is not obtained
-n Exit if lease is not obtained
-q Exit after obtaining lease
-R Release IP on exit
-f Run in foreground
-S Log to syslog too
-l Send 'information request' instead of 'solicit'
(used for servers which do not assign IPv6 addresses)
-r IPv6 Request this address ('no' to not request any IP)
-d Request prefix
-o Don't request any options (unless -O is given)
-O OPT Request option OPT from server (cumulative)
-x OPT:VAL Include option OPT in sent packets (cumulative)
Examples of string, numeric, and hex byte opts:
-x hostname:bbox - option 12
-x lease:3600 - option 51 (lease time)
-x 0x3d:0100BEEFC0FFEE - option 61 (client id)
-x 14:'"dumpfile"' - option 14 (shell-quoted)
Signals:
USR1 Renew lease
USR2 Release lease

udhcpd

udhcpd [-fS] [-I ADDR] [-a MSEC] [CONFFILE]

DHCP server

-f Run in foreground
-S Log to syslog too
-I ADDR Local address
-a MSEC Timeout for ARP ping (default 2000)
Signals:
USR1 Update lease file

uevent

uevent [PROG ARGS]

umount

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

Unmount filesystems

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

uname

uname [-amnrspvio]

Print system information

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

uncompress

uncompress [-cf] [FILE]...

Decompress FILEs (or stdin)

-c Write to stdout
-f Overwrite

unexpand

unexpand [-fa][-t N] [FILE]...

Convert spaces to tabs, writing to stdout

-a Convert all blanks
-f Convert only leading blanks
-t N Tabstops every N chars

uniq

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

Discard duplicate lines

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

unix2dos

unix2dos [-ud] [FILE]

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

-u dos2unix
-d unix2dos

unlink

unlink FILE

Delete FILE by calling unlink()

unlzma

unlzma [-cfk] [FILE]...

Decompress FILEs (or stdin)

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

unshare

unshare [OPTIONS] [PROG ARGS]

-m,--mount[=FILE] Unshare mount namespace
-u,--uts[=FILE] Unshare UTS namespace (hostname etc.)
-i,--ipc[=FILE] Unshare System V IPC namespace
-n,--net[=FILE] Unshare network namespace
-p,--pid[=FILE] Unshare PID namespace
-U,--user[=FILE] Unshare user namespace
-f Fork before execing PROG
-r Map current user to root (implies -U)
--mount-proc[=DIR] Mount /proc filesystem first (implies -m)
--propagation slave|shared|private|unchanged
Modify mount propagation in mount namespace
--setgroups allow|deny Control the setgroups syscall in user namespaces

unxz

unxz [-cfk] [FILE]...

Decompress FILEs (or stdin)

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

unzip

unzip [-lnojpqK] FILE[.zip] [FILE]... [-x FILE]... [-d DIR]

Extract FILEs from ZIP archive

-l List contents (with -q for short form)
-n Never overwrite files (default: ask)
-o Overwrite
-j Do not restore paths
-p Write to stdout
-t Test
-q Quiet
-K Do not clear SUID bit
-x FILE Exclude FILEs
-d DIR Extract into DIR

uptime

uptime

Display the time since the last boot

usleep

usleep N

Pause for N microseconds

uudecode

uudecode [-o OUTFILE] [INFILE]

Uudecode a file Finds OUTFILE in uuencoded source unless -o is given

uuencode

uuencode [-m] [FILE] STORED_FILENAME

Uuencode FILE (or stdin) to stdout

-m Use base64 encoding per RFC1521

vconfig

vconfig COMMAND [OPTIONS]

Create and remove virtual ethernet devices

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

Edit FILE

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

Show who is logged on

watch

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

Run PROG periodically

-n SEC Period (default 2)
-t Don't print header

watchdog

watchdog [-t N[ms]] [-T N[ms]] [-F] DEV

Periodically write to watchdog device DEV

-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

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

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

wget

Retrieve files via HTTP or FTP

--spider Only check URL existence: $? is 0 if exists
--header STR Add STR (of form 'header: value') to headers
--post-data STR Send STR using POST method
--post-file FILE Send FILE using POST method
--no-check-certificate Don't validate the server's certificate
-c Continue retrieval of aborted transfer
-q Quiet
-P DIR Save to DIR (default .)
-S Show server response
-T SEC Network read timeout is SEC seconds
-O FILE Save to FILE ('-' for stdout)
-o LOGFILE Log messages to FILE
-U STR Use STR for User-Agent header
-Y on/off Use proxy

which

which [-a] COMMAND...

Locate COMMAND

-a Show all matches

Show who is logged on

-a Show all
-H Print column headers

whoami

whoami

Print the user name associated with the current effective user id

xargs

xargs [OPTIONS] [PROG ARGS]

Run PROG on every item given by stdin

-0 NUL terminated input
-a FILE Read from FILE instead of stdin
-o Reopen stdin as /dev/tty
-r Don't run command if input is empty
-t Print the command on stderr before execution
-p Ask user whether to run each command
-E STR,-e[STR] STR stops input processing
-I STR Replace STR within PROG ARGS with input line
-n N Pass no more than N args to PROG
-s N Pass command line of no more than N bytes
-P N Run up to N PROGs in parallel
-x Exit if size is exceeded

Hex dump FILE (or stdin)

-g N Bytes per group
-c N Bytes per line
-p Show only hex bytes, assumes -c30
-i C include file style
-l LENGTH Show only first LENGTH bytes
-s OFFSET Skip OFFSET bytes
-o OFFSET Add OFFSET to displayed offset
-r Reverse (with -p, assumes no offsets in input)

Decompress FILEs (or stdin)

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

xzcat

xzcat [FILE]...

Decompress to stdout

Repeatedly print a line with STRING, or ’y’

zcat

zcat [FILE]...

Decompress to stdout

LIBC NSS

GNU Libc (glibc) uses the Name Service Switch (NSS) to configure the behavior of the C library for the local environment, and to configure how it reads system data, such as passwords and group information. This is implemented using an /etc/nsswitch.conf configuration file, and using one or more of the /lib/libnss_* libraries. BusyBox tries to avoid using any libc calls that make use of NSS. Some applets however, such as login and su, will use libc functions that require NSS.

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

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

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

MAINTAINER

Denis Vlasenko <vda.linux [AT] googlemail.com>

AUTHORS

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

Emanuele Aina <emanuele.aina [AT] tiscali.it>

run-parts

Erik Andersen <andersen [AT] 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 [AT] warwick.uk>

rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm

Jeff Angielski <jeff [AT] theptrgroup.com>

ftpput, ftpget

Edward Betts <edward [AT] debian.org>

expr, hostid, logname, whoami

John Beppu <beppu [AT] codepoet.org>

du, nslookup, sort

Brian Candler <B.Candler [AT] pobox.com>

tiny-ls(ls)

Randolph Chung <tausq [AT] debian.org>

fbset, ping, hostname

Dave Cinege <dcinege [AT] psychosis.com>

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

Jordan Crouse <jordan [AT] cosmicpenguin.net>

ipcalc

Magnus Damm <damm [AT] opensource.se>

tftp client insmod powerpc support

Larry Doolittle <ldoolitt [AT] recycle.gov>

pristine source directory compilation, lots of patches and fixes.

Glenn Engel <glenne [AT] engel.org>

httpd

Gennady Feldman <gfeldman [AT] gena01.com>

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

Karl M. Hegbloom <karlheg [AT] debian.org>

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

Daniel Jacobowitz <dan [AT] debian.org>

mktemp.c

Matt Kraai <kraai [AT] alumni.edu>

documentation, bugfixes, test suite

Stephan Linz <linz [AT] li-pro.net>

ipcalc, Red Hat equivalence

John Lombardo <john [AT] deltanet.com>

tr

Glenn McGrath <bug1 [AT] iinet.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 [AT] 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 [AT] 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 [AT] pixar.com>

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

Tim Riker <Tim [AT] Rikers.org>

bug fixes, member of fan club

Kent Robotti <robotti [AT] metconnect.com>

reset, tons and tons of bug reports and patches.

Chip Rosenthal <chip [AT] unicom.com>, <crosenth [AT] covad.com>

wget - Contributed by permission of Covad Communications

Pavel Roskin <proski [AT] gnu.org>

Lots of bugs fixes and patches.

Gyepi Sam <gyepi [AT] praxis-sw.com>

Remote logging feature for syslogd

Linus Torvalds <torvalds [AT] transmeta.com>

mkswap, fsck.minix, mkfs.minix

Mark Whitley <markw [AT] codepoet.org>

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

Charles P. Wright <cpwright [AT] villagenet.com>

gzip, mini-netcat(nc)

Enrique Zanardi <ezanardi [AT] ull.es>

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

Tito Ragusa <farmatito [AT] tiscali.it>

devfsd and size optimizations in strings, openvt and deallocvt.

Paul Fox <pgf [AT] foxharp.us>

vi editing mode for ash, various other patches/fixes

Roberto A. Foglietta <me [AT] roberto.name>

port: dnsd

Bernhard Reutner-Fischer <rep.dot.nop [AT] gmail.com>

misc

Mike Frysinger <vapier [AT] gentoo.org>

initial e2fsprogs, printenv, setarch, sum, misc

Jie Zhang <jie.zhang [AT] analog.com>

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