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BUSYBOX(1) busybox BUSYBOX(1)


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
will cause BusyBox to behave as 'ls' (if the 'ls' command has been compiled into BusyBox). Generally speaking, you should never need to make all these links yourself, as the BusyBox build system will do this for you when you run the 'make install' command.
If you invoke BusyBox with no arguments, it will provide you with a list of the applets that have been compiled into your BusyBox binary.


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


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


adjtimex [-q] [-o OFF] [-f FREQ] [-p TCONST] [-t TICK]
Read and optionally set system timebase parameters. See adjtimex(2)
        -q      Quiet
        -o OFF  Time offset, microseconds
        -f FREQ Frequency adjust, integer kernel units (65536 is 1ppm)
                (positive values make clock run faster)
        -t TICK Microseconds per tick, usually 10000
        -p TCONST
ar [-o] [-v] [-p] [-t] [-x] ARCHIVE FILES
Extract or list FILES from an ar archive
        -o      Preserve original dates
        -p      Extract to stdout
        -t      List
        -x      Extract
        -v      Verbose
arp [-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME] [-v] [-i IF] -d HOSTNAME [pub] [-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp] [-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub [-v] [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub
Manipulate ARP cache
        -a              Display (all) hosts
        -s              Set new ARP entry
        -d              Delete a specified entry
        -v              Verbose
        -n              Don't resolve names
        -i IF           Network interface
        -D              Read <hwaddr> from given device
        -A,-p AF        Protocol family
        -H HWTYPE       Hardware address type
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              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
ash [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]
Unix shell interpreter
        -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
        --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
        --flushbufs     Flush buffers
        --rereadpt      Reread partition table
Manage ethernet bridges
        addbr BRIDGE            Create BRIDGE
        delbr BRIDGE            Delete BRIDGE
        addif BRIDGE IFACE      Add IFACE to BRIDGE
        delif BRIDGE IFACE      Delete IFACE from BRIDGE
bunzip2 [-cf] [FILE]...
Decompress FILEs (or stdin)
        -c      Write to stdout
        -f      Force
bzcat FILE
Decompress to stdout
bzip2 [OPTIONS] [FILE]...
Compress FILEs (or stdin) with bzip2 algorithm
        -1..9   Compression level
        -d      Decompress
        -c      Write to stdout
        -f      Force
cal [-jy] [[MONTH] YEAR]
Display a calendar
        -j      Use julian dates
        -y      Display the entire year
cat [FILE]...
Concatenate FILEs and print them to stdout
chgrp [-RhLHPcvf]... GROUP FILE...
Change the group membership of each FILE to GROUP
        -R      Recurse
        -h      Affect symlinks instead of symlink targets
        -L      Traverse all symlinks to directories
        -H      Traverse symlinks on command line only
        -P      Don't traverse symlinks (default)
        -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
        -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
        -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
Run PROG with root directory set to NEWROOT
chvt N
Change the foreground virtual terminal to /dev/ttyN
Clear screen
cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]]
Compare FILE1 with FILE2 (or stdin)
        -l      Write the byte numbers (decimal) and values (octal)
                for all differing bytes
        -s      Quiet
Copy SOURCE(s) to DEST
        -a      Same as -dpR
        -R,-r   Recurse
        -d,-P   Preserve symlinks (default if -R)
        -L      Follow all symlinks
        -H      Follow symlinks on command line
        -p      Preserve file attributes if possible
        -f      Overwrite
        -i      Prompt before overwrite
        -l,-s   Create (sym)links
cpio [-dmvu] [-F FILE] [-H newc] [-tio] [EXTR_FILE]...
Extract or list files from a cpio archive, or create an archive using file list on stdin
Main operation mode:
        -t      List
        -i      Extract EXTR_FILEs (or all)
        -o      Create (requires -H newc)
        -d      Make leading directories
        -m      Preserve mtime
        -v      Verbose
        -u      Overwrite
        -F FILE Input (-t,-i,-p) or output (-o) file
        -H newc Archive format
cttyhack [PROG ARGS]
Give PROG a controlling tty if possible. Example for /etc/inittab (for busybox init): ::respawn:/bin/cttyhack /bin/sh Giving controlling tty to shell running with PID 1: $ exec cttyhack sh Starting interactive shell from boot shell script:
        setsid cttyhack sh
cut [OPTIONS] [FILE]...
Print selected fields from each input FILE to stdout
        -b LIST Output only bytes from LIST
        -c LIST Output only characters from LIST
        -d CHAR Use CHAR instead of tab as the field delimiter
        -s      Output only the lines containing delimiter
        -f N    Print only these fields
        -n      Ignored
date [OPTIONS] [+FMT] [TIME]
Display time (using +FMT), or set time
        [-s,--set] TIME Set time to TIME
        -u,--utc        Work in UTC (don't convert to local time)
        -R,--rfc-2822   Output RFC-2822 compliant date string
        -I[SPEC]        Output ISO-8601 compliant date string
                        SPEC='date' (default) for date only,
                        'hours', 'minutes', or 'seconds' for date and
                        time to the indicated precision
        -r,--reference FILE     Display last modification time of FILE
        -d,--date TIME  Display TIME, not 'now'
        -D FMT          Use FMT for -d TIME conversion
Recognized TIME formats:
        YYYY-MM-DD hh:mm[:ss]
        'date TIME' form accepts MMDDhhmm[[YY]YY][.ss] instead
Tiny RPN calculator. Operations: +, add, -, sub, *, mul, /, div, %, mod, and, or, not, eor, p - print top of the stack (without popping), f - print entire stack, o - pop the value and set output radix (must be 10, 16, 8 or 2). Examples: 'dc 2 2 add p' -> 4, 'dc 8 8 * 2 2 + / p' -> 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
        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
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
df [-Pkmhai] [-B SIZE] [FILESYSTEM]...
Print filesystem usage statistics
        -P      POSIX output format
        -k      1024-byte blocks (default)
        -m      1M-byte blocks
        -h      Human readable (e.g. 1K 243M 2G)
        -a      Show all filesystems
        -i      Inodes
        -B SIZE Blocksize
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 FILENAME
Strip non-directory suffix from FILENAME
dmesg [-c] [-n LEVEL] [-s SIZE]
Print or control the kernel ring buffer
        -c              Clear ring buffer after printing
        -n LEVEL        Set console logging level
        -s SIZE         Buffer size
dos2unix [-ud] [FILE]
Convert FILE in-place from DOS to Unix format. When no file is given, use stdin/stdout.
        -u      dos2unix
        -d      unix2dos
du [-aHLdclsxhmk] [FILE]...
Summarize disk space used for each FILE and/or directory
        -a      Show file sizes too
        -L      Follow all symlinks
        -H      Follow symlinks on command line
        -d N    Limit output to directories (and files with -a) of depth < N
        -c      Show grand total
        -l      Count sizes many times if hard linked
        -s      Display only a total for each argument
        -x      Skip directories on different filesystems
        -h      Sizes in human readable format (e.g., 1K 243M 2G)
        -m      Sizes in megabytes
        -k      Sizes in kilobytes (default)
dumpkmap > keymap
Print a binary keyboard translation table to stdout
dumpleases [-r|-a] [-f LEASEFILE]
Display DHCP leases granted by udhcpd
        -f,--file=FILE  Lease file
        -r,--remaining  Show remaining time
        -a,--absolute   Show expiration time
echo [-neE] [ARG]...
Print the specified ARGs to stdout
        -n      Suppress trailing newline
        -e      Interpret backslash escapes (i.e., \t=tab)
        -E      Don't interpret backslash escapes (default)
env [-iu] [-] [name=value]... [PROG ARGS]
Print the current environment or run PROG after setting up the specified environment
        -, -i   Start with an empty environment
        -u      Remove variable from the environment
expand [-i] [-t N] [FILE]...
Convert tabs to spaces, writing to stdout
        -i,--initial    Don't convert tabs after non blanks
        -t,--tabs=N     Tabstops every N chars
Print the value of EXPRESSION to stdout
        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.
Return an exit code of FALSE (1)
Search for files and perform actions on them. First failed action stops processing of current file. Defaults: PATH is current directory, action is '-print'
        -follow         Follow symlinks
        -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 )     Group actions for -o / -a
        ! ACT           Invert ACT's success/failure
        ACT1 [-a] ACT2  If ACT1 fails, stop, else do ACT2
        ACT1 -o ACT2    If ACT1 succeeds, stop, else do ACT2
                        Note: -a has higher priority than -o
        -name PATTERN   Match file name (w/o directory name) to PATTERN
        -iname PATTERN  Case insensitive -name
        -path PATTERN   Match path to PATTERN
        -ipath PATTERN  Case insensitive -path
        -regex PATTERN  Match path to regex PATTERN
        -type X         File type is X (one of: f,d,l,b,c,...)
        -perm MASK      At least one mask bit (+MASK), all bits (-MASK),
                        or exactly MASK bits are set in file's mode
        -mtime DAYS     mtime is greater than (+N), less than (-N),
                        or exactly N days in the past
        -mmin MINS      mtime is greater than (+N), less than (-N),
                        or exactly N minutes in the past
        -newer FILE     mtime is more recent than FILE's
        -inum N         File has inode number N
        -user NAME/ID   File is owned by given user
        -group NAME/ID  File is owned by given group
        -size N[bck]    File size is N (c:bytes,k:kbytes,b:512 bytes(def.))
                        +/-N: file size is bigger/smaller than N
        -links N        Number of links is greater than (+N), less than (-N),
                        or exactly N
        -prune          If current file is directory, don't descend into it
If none of the following actions is specified, -print is assumed
        -print          Print file name
        -print0         Print file name, NUL terminated
        -exec CMD ARG ; Run CMD with all instances of {} replaced by
                        file name. Fails if CMD exits with nonzero
fold [-bs] [-w WIDTH] [FILE]...
Wrap input lines in each FILE (or stdin), writing to stdout
        -b      Count bytes rather than columns
        -s      Break at spaces
        -w      Use WIDTH columns instead of 80
free [-b/k/m/g]
Display the amount of free and used system memory
freeramdisk DEVICE
Free all memory used by the specified ramdisk
Download a file via FTP
        -c,--continue           Continue previous transfer
        -v,--verbose            Verbose
        -u,--username USER      Username
        -p,--password PASS      Password
        -P,--port NUM           Port
Upload a file to a FTP server
        -v,--verbose            Verbose
        -u,--username USER      Username
        -p,--password PASS      Password
        -P,--port NUM           Port
        -a,--alternative                Allow long options starting with single -
        -l,--longoptions=LOPT[,...]     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
O=`getopt -l bb: -- ab:c:: "$@"` || exit 1 eval set -- "$O" while true; do case "$1" in -a) echo A; shift;; -b|--bb) echo "B:'$2'"; shift 2;; -c) case "$2" in "") echo C; shift 2;; *) echo "C:'$2'"; shift 2;; esac;; --) shift; break;; *) echo Error; exit 1;; esac done
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 [-HhnlLoqvsriwFEz] [-m N] [-A/B/C N] PATTERN/-e PATTERN.../-f FILE [FILE]...
Search for PATTERN in FILEs (or stdin)
        -H      Add 'filename:' prefix
        -h      Do not add 'filename:' prefix
        -n      Add 'line_no:' prefix
        -l      Show only names of files that match
        -L      Show only names of files that don't match
        -c      Show only count of matching lines
        -o      Show only the matching part of line
        -q      Quiet. Return 0 if PATTERN is found, 1 otherwise
        -v      Select non-matching lines
        -s      Suppress open and read errors
        -r      Recurse
        -i      Ignore case
        -w      Match whole words only
        -x      Match whole lines only
        -F      PATTERN is a literal (not regexp)
        -E      PATTERN is an extended regexp
        -z      Input is NUL terminated
        -m N    Match up to N times per file
        -A N    Print N lines of trailing context
        -B N    Print N lines of leading context
        -C N    Same as '-A N -B N'
        -e PTRN Pattern to match
        -f FILE Read pattern from file
groups [USER]
Print the group memberships of USER or for the current process
gunzip [-cft] [FILE]...
Decompress FILEs (or stdin)
        -c      Write to stdout
        -f      Force
        -t      Test file integrity
gzip [-cfd] [FILE]...
Compress FILEs (or stdin)
        -d      Decompress
        -c      Write to stdout
        -f      Force
halt [-d DELAY] [-n] [-f] [-w]
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 [OPTIONS] [FILE]...
Print first 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a filename header.
        -n N[kbm]       Print first N lines
        -c N[kbm]       Print first N bytes
        -q              Never print headers
        -v              Always print headers
N may be suffixed by k (x1024), b (x512), or m (x1024^2).
hexdump [-bcCdefnosvx] [FILE]...
Display FILEs (or stdin) in a user specified format
        -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
Print out a unique 32-bit identifier for the machine
Get or set hostname or DNS domain name
        -s      Short
        -i      Addresses for the hostname
        -d      DNS domain name
        -f      Fully qualified domain name
        -F FILE Use FILE's content as hostname
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              Don't daemonize
        -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 [-r|--show] [-s|--hctosys] [-w|--systohc] [-t|--systz] [-l|--localtime] [-u|--utc] [-f|--rtc FILE]
Query and set hardware clock (RTC)
        -r      Show hardware clock time
        -s      Set system time from hardware clock
        -w      Set hardware clock from system time
        -t      Set in-kernel timezone, correct system time
                if hardware clock is in local time
        -u      Assume hardware clock is kept in UTC
        -l      Assume hardware clock is kept in local time
        -f FILE Use specified device (e.g. /dev/rtc2)
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 [-a] interface [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] ...
Init is the parent of all processes
Load the specified kernel modules into the kernel
ionice [-c 1-3] [-n 0-7] [-p PID] [PROG]
Change I/O priority and class
        -c      Class. 1:realtime 2:best-effort 3:idle
        -n      Priority
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] }
Calculate IP network settings from a IP address
        -b,--broadcast  Display calculated broadcast address
        -n,--network    Display calculated network address
        -m,--netmask    Display default netmask for IP
        -p,--prefix     Display the prefix for IP/NETMASK
        -h,--hostname   Display first resolved host name
        -s,--silent     Don't ever display error messages
kill [-l] [-SIG] PID...
Send a signal (default: TERM) to given PIDs
        -l      List all signal names and numbers
killall [-l] [-q] [-SIG] PROCESS_NAME...
Send a signal (default: TERM) to given processes
        -l      List all signal names and numbers
        -q      Don't complain if no processes were killed
klogd [-c N] [-n]
Kernel logger
        -c N    Print to console messages more urgent than prio N (1-8)
        -n      Run in foreground
Show listing of the last users that logged into the system
less [-EMmNh~I?] [FILE]...
View FILE (or stdin) one screenful at a time
        -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 EOF
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
loadfont < font
Load a console font from stdin
loadkmap < keymap
Load a binary keyboard translation table from stdin
Write MESSAGE (or stdin) to syslog
        -s      Log to stderr as well as the system log
        -t TAG  Log using the specified tag (defaults to user name)
        -p PRIO Priority (numeric or facility.level pair)
login [-p] [-h HOST] [[-f] USER]
Begin a new session on the system
        -f      Don't authenticate (user already authenticated)
        -h      Name of the remote host
        -p      Preserve environment
Print the name of the current user
logread [-f]
Show messages in syslogd's circular buffer
        -f      Output data as log grows
losetup [-r] [-o OFS] LOOPDEV FILE - associate loop devices losetup -d LOOPDEV - disassociate losetup [-f] - show
        -o OFS  Start OFS bytes into FILE
        -r      Read-only
        -f      Show first free loop device
ls [-1AaCxdLHRFplinsehrSXvctu] [-w WIDTH] [FILE]...
List directory contents
        -1      One column output
        -a      Include entries which start with .
        -A      Like -a, but exclude . and ..
        -C      List by columns
        -x      List by lines
        -d      List directory entries instead of contents
        -L      Follow symlinks
        -H      Follow symlinks on command line
        -R      Recurse
        -p      Append / to dir entries
        -F      Append indicator (one of */=@|) to entries
        -l      Long listing format
        -i      List inode numbers
        -n      List numeric UIDs and GIDs instead of names
        -s      List allocated blocks
        -e      List full date and time
        -h      List sizes in human readable format (1K 243M 2G)
        -r      Sort in reverse order
        -S      Sort by size
        -X      Sort by extension
        -v      Sort by version
        -c      With -l: sort by ctime
        -t      With -l: sort by mtime
        -u      With -l: sort by atime
        -w N    Assume the terminal is N columns wide
        --color[={always,never,auto}]   Control coloring
List the currently loaded kernel modules
lzcat FILE
Decompress to stdout
lzma -d [-cf] [FILE]...
Decompress FILE (or stdin)
        -d      Decompress
        -c      Write to stdout
        -f      Force
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 [-s]
mdev -s is to be run during boot to scan /sys and populate /dev.
Bare mdev is a kernel hotplug helper. To activate it: echo /sbin/mdev >/proc/sys/kernel/hotplug
It uses /etc/mdev.conf with lines [-]DEVNAME UID:GID PERM [>|=PATH]|[!] [@|$|*PROG] where DEVNAME is device name regex, @major,minor[-minor2], or environment variable regex. A common use of the latter is to load modules for hotplugged devices:
        $MODALIAS=.* 0:0 660 @modprobe "$MODALIAS"
If /dev/mdev.seq file exists, mdev will wait for its value to match $SEQNUM variable. This prevents plug/unplug races. To activate this feature, create empty /dev/mdev.seq at boot.
microcom [-d DELAY] [-t TIMEOUT] [-s SPEED] [-X] TTY
Copy bytes for stdin to TTY and from TTY to stdout
        -d      Wait up to DELAY ms for TTY output before sending every
                next byte to it
        -t      Exit if both stdin and TTY are silent for TIMEOUT ms
        -s      Set serial line to SPEED
        -X      Disable special meaning of NUL and Ctrl-X from stdin
        -m MODE Mode
        -p      No error if exists; make parent directories as needed
mkfifo [-m MODE] NAME
Create named pipe
        -m MODE Mode (default a=rw)
Create a special file (block, character, or pipe)
        -m MODE Creation mode (default a=rw)
        b       Block device
        c or u  Character device
        p       Named pipe (MAJOR and MINOR are ignored)
Prepare BLOCKDEV to be used as swap partition
        -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). Without TEMPLATE, -t tmp.XXXXXX is assumed.
        -d      Make directory, not file
        -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 [-adlp0] [-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              Separate output with NULs
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 [FILE]...
View FILE (or stdin) one screenful at a time
Mount a filesystem. Filesystem autodetection requires /proc.
        -a              Mount all filesystems in fstab
        -i              Don't run mount helper
        -r              Read-only mount
        -w              Read-write mount (default)
        -t FSTYPE[,...] Filesystem type(s)
        -O OPT          Mount only filesystems with option OPT (-a only)
-o OPT:
        loop            Ignored (loop devices are autodetected)
        [a]sync         Writes are [a]synchronous
        [no]atime       Disable/enable updates to inode access times
        [no]diratime    Disable/enable atime updates to directories
        [no]relatime    Disable/enable atime updates relative to modification time
        [no]dev         (Dis)allow use of special device files
        [no]exec        (Dis)allow use of executable files
        [no]suid        (Dis)allow set-user-id-root programs
        [r]shared       Convert [recursively] to a shared subtree
        [r]slave        Convert [recursively] to a slave subtree
        [r]private      Convert [recursively] to a private subtree
        [un]bindable    Make mount point [un]able to be bind mounted
        [r]bind         Bind a file or directory [recursively] to another location
        move            Relocate an existing mount point
        remount         Remount a mounted filesystem, changing flags
        ro/rw           Same as -r/-w
There are filesystem-specific -o flags.
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 [-fin] SOURCE DEST or: mv [-fin] SOURCE... DIRECTORY
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY
        -f      Don't prompt before overwriting
        -i      Interactive, prompt before overwrite
        -n      Don't overwrite an existing file
nameif [-s] [-c FILE] [IFNAME HWADDR]...
Rename network interface while it in the down state. The device with address HWADDR is renamed to IFACE.
        -c FILE Configuration file (default: /etc/mactab)
        -s      Log to syslog
nc [-iN] [-wN] [-l] [-p PORT] [-f FILE|IPADDR PORT] [-e PROG]
Open a pipe to IP:PORT or FILE
        -e PROG Run PROG after connect
        -l      Listen mode, for inbound connects
                (use -l twice with -e for persistent server)
        -p PORT Local port
        -w SEC  Timeout for connect
        -i SEC  Delay interval for lines sent
        -f FILE Use file (ala /dev/ttyS0) instead of network
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
nslookup [HOST] [SERVER]
Query the nameserver for the IP address of the given HOST optionally using a specified DNS server
od [-abcdfhilovxs] [-t TYPE] [-A RADIX] [-N SIZE] [-j SKIP] [-S MINSTR] [-w WIDTH] [FILE...]
Print FILEs (or stdin) unambiguously, as octal bytes by default
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
        -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
        -E,--remove-empty-files Remove output files if they become empty
pidof [NAME]...
List PIDs of all processes with names that match NAMEs
Send ICMP ECHO_REQUEST packets to network hosts
        -4,-6           Force IP or IPv6 name resolution
        -c CNT          Send only CNT pings
        -s SIZE         Send SIZE data bytes in packets (default:56)
        -t TTL          Set TTL
        -I IFACE/IP     Use interface or IP address as source
        -W SEC          Seconds to wait for the first response (default:10)
                        (after all -c CNT packets are sent)
        -w SEC          Seconds until ping exits (default:infinite)
                        (can exit earlier with -c CNT)
        -q              Quiet, only displays output at start
                        and when finished
Send ICMP ECHO_REQUEST packets to network hosts
        -c CNT          Send only CNT pings
        -s SIZE         Send SIZE data bytes in packets (default:56)
        -I IFACE/IP     Use interface or IP address as source
        -q              Quiet, only 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
        -d SEC  Delay interval
        -n      Do not sync
        -f      Force (don't go through init)
printf FORMAT [ARG]...
Format and print ARG(s) according to FORMAT (a-la C printf)
ps [-o COL1,COL2=HEADER] [-T]
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 [-sp] HOST
Get and possibly set the system date and time from a remote HOST
        -s      Set the system date and time (default)
        -p      Print the date and time
readlink [-fnv] FILE
Display the value of a symlink
        -f      Canonicalize by following all symlinks
        -n      Don't add newline
        -v      Verbose
realpath FILE...
Return the absolute pathnames of given FILE
reboot [-d DELAY] [-n] [-f]
Reboot the system
        -d SEC  Delay interval
        -n      Do not sync
        -f      Force (don't go through init)
renice {{-n INCREMENT} | PRIORITY} [[-p | -g | -u] ID...]
Change scheduling priority for a running process
        -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 the screen
rev [FILE]...
Reverse lines of FILE
rm [-irf] FILE...
Remove (unlink) FILEs
        -i      Always prompt before removing
        -f      Never prompt
        -R,-r   Recurse
Remove DIRECTORY if it is empty
        -p|--parents    Include parents
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 [{add|del|delete}]
Edit kernel routing tables
        -n      Don't resolve names
        -e      Display other/more information
        -A inet{6}      Select address family
rpm -i PACKAGE.rpm; rpm -qp[ildc] PACKAGE.rpm
Manipulate RPM packages
        -i      Install package
        -qp     Query package
        -i      Show information
        -l      List contents
        -d      List documents
        -c      List config files
rpm2cpio package.rpm
Output a cpio archive of the rpm file
run-parts [-t] [-a ARG] [-u MASK] DIRECTORY
Run a bunch of scripts in DIRECTORY
        -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
sed [-inr] [-f FILE]... [-e CMD]... [FILE]... or: sed [-inr] CMD [FILE]...
        -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.
        -w      Pad to last with leading zeros
        -s SEP  String separator
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.
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.
sh [-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]
Unix shell interpreter
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 [-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
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
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 [-nrugMcszbdfimSTokt] [-o FILE] [-k start[.offset][opts][,end[.offset][opts]] [-t CHAR] [FILE]...
Sort lines of text
        -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/{exe,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
        -o,--oknodo             Exit with status 0 if nothing is done
        -v,--verbose            Verbose
        -q,--quiet              Quiet
stat [OPTIONS] FILE...
Display file (default) or filesystem status
        -c fmt  Use the specified format
        -f      Display filesystem status
        -L      Follow links
        -t      Display info in terse form
Valid format sequences for files:
 %a     Access rights in octal
 %A     Access rights in human readable form
 %b     Number of blocks allocated (see %B)
 %B     The size in bytes of each block reported by %b
 %d     Device number in decimal
 %D     Device number in hex
 %f     Raw mode in hex
 %F     File type
 %g     Group ID of owner
 %G     Group name of owner
 %h     Number of hard links
 %i     Inode number
 %n     File name
 %N     File name, with -> TARGET if symlink
 %o     I/O block size
 %s     Total size, in bytes
 %t     Major device type in hex
 %T     Minor device type in hex
 %u     User ID of owner
 %U     User name of owner
 %x     Time of last access
 %X     Time of last access as seconds since Epoch
 %y     Time of last modification
 %Y     Time of last modification as seconds since Epoch
 %z     Time of last change
 %Z     Time of last change as seconds since Epoch
Valid format sequences for file systems:
 %a     Free blocks available to non-superuser
 %b     Total data blocks in file system
 %c     Total file nodes in file system
 %d     Free file nodes in file system
 %f     Free blocks in file system
 %i     File System ID in hex
 %l     Maximum length of filenames
 %n     File name
 %s     Block size (for faster transfer)
 %S     Fundamental block size (for block counts)
 %t     Type in hex
 %T     Type in human readable form
strings [-afo] [-n LEN] [FILE]...
Display printable strings in a binary file
        -a      Scan whole file (default)
        -f      Precede strings with filenames
        -n LEN  At least LEN characters form a string (default 4)
        -o      Precede strings with decimal offsets
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
swapoff [-a] [DEVICE]
Stop swapping on DEVICE
        -a      Stop swapping on all swap devices
swapon [-a] [DEVICE]
Start swapping on DEVICE
        -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.
        -c DEV  Reopen stdio to DEV after switch
Write all buffered blocks to disk
sysctl [OPTIONS] [VALUE]...
Configure kernel parameters at runtime
        -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)
        -n              Run in foreground
        -O FILE         Log to FILE (default:/var/log/messages)
        -l N            Log only messages more urgent than prio N (1-8)
        -S              Smaller output
        -R HOST[:PORT]  Log to IP or hostname on PORT (default PORT=514/UDP)
        -L              Log locally and via network (default is network only if -R)
        -C[size_kb]     Log to shared mem buffer (use logread to read it)
tac [FILE]...
Concatenate FILEs and print them in reverse
tail [OPTIONS] [FILE]...
Print last 10 lines of each FILE (or stdin) to stdout. With more than one FILE, precede each with a filename header.
        -f              Print data as file grows
        -s SECONDS      Wait SECONDS between reads with -f
        -n N[kbm]       Print last N lines
        -c N[kbm]       Print last N bytes
        -q              Never print headers
        -v              Always print headers
N may be suffixed by k (x1024), b (x512), or m (x1024^2). If N starts with a '+', output begins with the Nth item from the start of each file, not from the end.
tar -[cxtZzjahmvO] [-f TARFILE] [-C DIR] [FILE]...
Create, extract, or list files from a tar file
        c       Create
        x       Extract
        t       List
        f       Name of TARFILE ('-' for stdin/out)
        C       Change to DIR before operation
        v       Verbose
        Z       (De)compress using compress
        z       (De)compress using gzip
        j       (De)compress using bzip2
        a       (De)compress using lzma
        O       Extract to stdout
        h       Follow symlinks
        m       Don't restore mtime
taskset [-p] [MASK] [PID | PROG ARGS]
Set or get CPU affinity
        -p      Operate on an existing PID
tee [-ai] [FILE]...
Copy stdin to each FILE, and also to stdout
        -a      Append to the given FILEs, don't overwrite
        -i      Ignore interrupt signals (SIGINT)
telnet [-a] [-l USER] HOST [PORT]
Connect to telnet server
        -a      Automatic login with $USER variable
        -l USER Automatic login as USER
Check file types, compare values etc. Return a 0/1 exit code depending on logical value of EXPRESSION
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 of SIZE octets
time [-v] PROG ARGS
Run PROG, display resource usage when it exits
        -v      Verbose
timeout [-t SECS] [-s SIG] PROG ARGS
Runs PROG. Sends SIG to it if it is not gone in SECS seconds. Defaults: SECS: 10, SIG: TERM.
top [-b] [-nCOUNT] [-dSECONDS]
Provide a view of process activity in real time. Read the status of all processes from /proc each SECONDS and display a screenful of them. Keys:
        N/M/P/T: sort by pid/mem/cpu/time
        R: reverse sort
        H: toggle threads
        Q,^C: exit
        -b      Batch mode
        -n N    Exit after N iterations
        -d N    Delay between updates
touch [-c] [-d DATE] [-t DATE] [-r FILE] FILE...
Update the last-modified date on the given FILE[s]
        -c      Don't create files
        -d DT   Date/time to use
        -t DT   Date/time to use
        -r FILE Use FILE's date/time
tr [-cds] STRING1 [STRING2]
Translate, squeeze, or delete characters from stdin, writing to stdout
        -c      Take complement of STRING1
        -d      Delete input characters coded STRING1
        -s      Squeeze multiple output characters of STRING2 into one character
traceroute [-46FIldnrv] [-f 1ST_TTL] [-m MAXTTL] [-p PORT] [-q PROBES] [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-g GATEWAY] [-i IFACE] [-z PAUSE_MSEC] HOST [BYTES]
Trace the route to HOST
        -4,-6   Force IP or IPv6 name resolution
        -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)
traceroute6 [-dnrv] [-m MAXTTL] [-p PORT] [-q PROBES] [-s SRC_IP] [-t TOS] [-w WAIT_SEC] [-i IFACE] HOST [BYTES]
Trace the route to HOST
        -d      Set SO_DEBUG options to socket
        -n      Print numeric addresses
        -r      Bypass routing tables, send directly to HOST
        -v      Verbose
        -m      Max time-to-live (max number of hops)
        -p      Base UDP port number used in probes
                (default is 33434)
        -q      Number of probes per TTL (default 3)
        -s      IP address to use as the source address
        -t      Type-of-service in probe packets (default 0)
        -w      Time in seconds to wait for a response (default 3)
Return an exit code of TRUE (0)
Print file name of stdin's terminal
        -s      Print nothing, only return exit status
udhcpc [-fbnqoCRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE] [-V VENDOR] [-x OPT:VAL]... [-O OPT]...
        -i,--interface IFACE    Interface to use (default eth0)
        -p,--pidfile FILE       Create pidfile
        -s,--script PROG        Run PROG at DHCP events (default /etc/udhcpc/default.script)
        -B,--broadcast          Request broadcast replies
        -t,--retries N          Send up to N discover packets
        -T,--timeout N          Pause between packets (default 3 seconds)
        -A,--tryagain N         Wait N seconds after failure (default 20)
        -f,--foreground         Run in foreground
        -b,--background         Background if lease is not obtained
        -n,--now                Exit if lease is not obtained
        -q,--quit               Exit after obtaining lease
        -R,--release            Release IP on exit
        -S,--syslog             Log to syslog too
        -a,--arping             Use arping to validate offered address
        -O,--request-option OPT Request option OPT from server (cumulative)
        -o,--no-default-options Don't request any options (unless -O is given)
        -r,--request IP         Request this IP address
        -x OPT:VAL              Include option OPT in sent packets (cumulative)
                                Examples of string, numeric, and hex byte opts:
                                -x hostname:bbox - option 12
                                -x lease:3600 - option 51 (lease time)
                                -x 0x3d:0100BEEFC0FFEE - option 61 (client id)
        -F,--fqdn NAME          Ask server to update DNS mapping for NAME
        -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')
        -C,--clientid-none      Don't send MAC as client identifier
        USR1    Renew lease
        USR2    Release lease
udhcpd [-fS] [CONFFILE]
DHCP server
        -f      Run in foreground
        -S      Log to syslog too
Unmount file systems
        -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      Don't free loop device even if it has been used
uname [-amnrspv]
Print system information
        -a      Print all
        -m      The machine (hardware) type
        -n      Hostname
        -r      OS release
        -s      OS name (default)
        -p      Processor type
        -v      OS version
uncompress [-cf] [FILE]...
Decompress .Z file[s]
        -c      Write to stdout
        -f      Overwrite
unexpand [-fa][-t N] [FILE]...
Convert spaces to tabs, writing to stdout
        -a,--all        Convert all blanks
        -f,--first-only Convert only leading blanks
        -t,--tabs=N     Tabstops every N chars
uniq [-cdu][-f,s,w N] [INPUT [OUTPUT]]
Discard duplicate lines
        -c      Prefix lines by the number of occurrences
        -d      Only print duplicate lines
        -u      Only print unique lines
        -f N    Skip first N fields
        -s N    Skip first N chars (after any skipped fields)
        -w N    Compare N characters in line
unix2dos [-ud] [FILE]
Convert FILE in-place from Unix to DOS format. When no file is given, use stdin/stdout.
        -u      dos2unix
        -d      unix2dos
unlzma [-cf] [FILE]...
Decompress FILE (or stdin)
        -c      Write to stdout
        -f      Force
unxz [-cf] [FILE]...
Decompress FILE (or stdin)
        -c      Write to stdout
        -f      Force
unzip [-opts[modifiers]] FILE[.zip] [LIST] [-x XLIST] [-d DIR]
Extract files from ZIP archives
        -l      List archive contents (with -q for short form)
        -n      Never overwrite files (default)
        -o      Overwrite
        -p      Send output to stdout
        -q      Quiet
        -x XLST Exclude these files
        -d DIR  Extract files into DIR
Display the time since the last boot
usleep N
Pause for N microseconds
uudecode [-o OUTFILE] [INFILE]
Uudecode a file Finds OUTFILE in uuencoded source unless -o is given
uuencode [-m] [FILE] STORED_FILENAME
Uuencode FILE (or stdin) to stdout
        -m      Use base64 encoding per RFC1521
Create and remove virtual ethernet devices
        add             IFACE VLAN_ID
        rem             VLAN_NAME
        set_flag        IFACE 0|1 VLAN_QOS
        set_egress_map  VLAN_NAME SKB_PRIO VLAN_QOS
        set_ingress_map VLAN_NAME SKB_PRIO VLAN_QOS
        set_name_type   NAME_TYPE
vi [OPTIONS] [FILE]...
        -c      Initial command to run ($EXINIT also available)
        -R      Read-only
        -H      Short help regarding available features
watch [-n SEC] [-t] PROG ARGS
Run PROG periodically
        -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
        -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 [-cmlwL] [FILE]...
Count lines, words, and bytes for each FILE (or stdin)
        -c      Count bytes
        -m      Count characters
        -l      Count newlines
        -w      Count words
        -L      Print longest line length
wget [-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
        -s      Spider mode - only check file existence
        -c      Continue retrieval of aborted transfer
        -q      Quiet
        -P DIR  Save to DIR (default .)
        -O FILE Save to FILE ('-' for stdout)
        -U STR  Use STR for User-Agent header
        -Y      Use proxy ('on' or 'off')
which [COMMAND]...
Locate a COMMAND
who [-a]
Show who is logged on
        -a      Show all
        -H      Print column headers
Print the user name associated with the current effective user id
Run PROG on every item given by stdin
        -p      Ask user whether to run each command
        -r      Don't run command if input is empty
        -0      Input is separated by NUL characters
        -t      Print the command on stderr before execution
        -e[STR] STR stops input processing
        -n N    Pass no more than N args to PROG
        -s N    Pass command line of no more than N bytes
        -x      Exit if size is exceeded
xz -d [-cf] [FILE]...
Decompress FILE (or stdin)
        -d      Decompress
        -c      Write to stdout
        -f      Force
xzcat FILE
Decompress to stdout
yes [STRING]
Repeatedly output a line with STRING, or 'y'
zcat FILE
Decompress to stdout


GNU Libc (glibc) uses the Name Service Switch (NSS) to configure the behavior of the C library for the local environment, and to configure how it reads system data, such as passwords and group information. This is implemented using an /etc/nsswitch.conf configuration file, and using one or more of the /lib/libnss_* libraries. BusyBox tries to avoid using any libc calls that make use of NSS. Some applets however, such as login and su, will use libc functions that require NSS.
If you enable CONFIG_USE_BB_PWD_GRP, BusyBox will use internal functions to directly access the /etc/passwd, /etc/group, and /etc/shadow files without using NSS. This may allow you to run your system without the need for installing any of the NSS configuration files and libraries.
When used with glibc, the BusyBox 'networking' applets will similarly require that you install at least some of the glibc NSS stuff (in particular, /etc/nsswitch.conf, /lib/libnss_dns*, /lib/libnss_files*, and /lib/libresolv*).
Shameless Plug: As an alternative, one could use a C library such as uClibc. In addition to making your system significantly smaller, uClibc does not require the use of any NSS support files or libraries.


Denis Vlasenko <>


The following people have contributed code to BusyBox whether they know it or not. If you have written code included in BusyBox, you should probably be listed here so you can obtain your bit of eternal glory. If you should be listed here, or the description of what you have done needs more detail, or is incorrect, please send in an update.
Emanuele Aina <>
Erik Andersen <>
    Tons of new stuff, major rewrite of most of the
    core apps, tons of new apps as noted in header files.
    Lots of tedious effort writing these boring docs that
    nobody is going to actually read.
Laurence Anderson <>
    rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm
Jeff Angielski <>
    ftpput, ftpget
Edward Betts <>
    expr, hostid, logname, whoami
John Beppu <>
    du, nslookup, sort
Brian Candler <>
Randolph Chung <>
    fbset, ping, hostname
Dave Cinege <>
    more(v2), makedevs, dutmp, modularization, auto links file,
    various fixes, Linux Router Project maintenance
Jordan Crouse <>
Magnus Damm <>
    tftp client insmod powerpc support
Larry Doolittle <>
    pristine source directory compilation, lots of patches and fixes.
Glenn Engel <>
Gennady Feldman <>
    Sysklogd (single threaded syslogd, IPC Circular buffer support,
    logread), various fixes.
Karl M. Hegbloom <>
    cp_mv.c, the test suite, various fixes to utility.c, &c.
Daniel Jacobowitz <>
Matt Kraai <>
    documentation, bugfixes, test suite
Stephan Linz <>
    ipcalc, Red Hat equivalence
John Lombardo <>
Glenn McGrath <>
    Common unarchiving code and unarchiving applets, ifupdown, ftpgetput,
    nameif, sed, patch, fold, install, uudecode.
    Various bugfixes, review and apply numerous patches.
Manuel Novoa III <>
    cat, head, mkfifo, mknod, rmdir, sleep, tee, tty, uniq, usleep, wc, yes,
    mesg, vconfig, make_directory, parse_mode, dirname, mode_string,
    get_last_path_component, simplify_path, and a number trivial libbb routines
    also bug fixes, partial rewrites, and size optimizations in
    ash, basename, cal, cmp, cp, df, du, echo, env, ln, logname, md5sum, mkdir,
    mv, realpath, rm, sort, tail, touch, uname, watch, arith, human_readable,
    interface, dutmp, ifconfig, route
Vladimir Oleynik <>
    cmdedit; xargs(current), httpd(current);
    ports: ash, crond, fdisk, inetd, stty, traceroute, top;
    locale, various fixes
    and irreconcilable critic of everything not perfect.
Bruce Perens <>
    Original author of BusyBox in 1995, 1996. Some of his code can
    still be found hiding here and there...
Tim Riker <>
    bug fixes, member of fan club
Kent Robotti <>
    reset, tons and tons of bug reports and patches.
Chip Rosenthal <>, <>
    wget - Contributed by permission of Covad Communications
Pavel Roskin <>
    Lots of bugs fixes and patches.
Gyepi Sam <>
    Remote logging feature for syslogd
Linus Torvalds <>
    mkswap, fsck.minix, mkfs.minix
Mark Whitley <>
    grep, sed, cut, xargs(previous),
    style-guide, new-applet-HOWTO, bug fixes, etc.
Charles P. Wright <>
    gzip, mini-netcat(nc)
Enrique Zanardi <>
    tarcat (since removed), loadkmap, various fixes, Debian maintenance
Tito Ragusa <>
    devfsd and size optimizations in strings, openvt and deallocvt.
Paul Fox <>
    vi editing mode for ash, various other patches/fixes
Roberto A. Foglietta <>
    port: dnsd
Bernhard Reutner-Fischer <>
Mike Frysinger <>
    initial e2fsprogs, printenv, setarch, sum, misc
Jie Zhang <>
    fixed two bugs in msh and hush (exitcode of killed processes)
2012-09-20 version 1.20.2