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, add-shell, addgroup, adduser, adjtimex, ar, arch, arp,
            arping, ascii, ash, awk, base32, base64, basename, bc, beep,
            blkdiscard, blkid, blockdev, bootchartd, brctl, bunzip2, bzcat,
            bzip2, cal, cat, chat, chattr, chgrp, chmod, chown, chpasswd, chpst,
            chroot, chrt, chvt, cksum, clear, cmp, comm, conspy, cp, cpio,
            crc32, crond, crontab, cryptpw, cttyhack, cut, date, dc, dd,
            deallocvt, delgroup, deluser, depmod, devmem, df, dhcprelay, diff,
            dirname, dmesg, dnsd, dnsdomainname, dos2unix, dpkg, dpkg-deb, du,
            dumpkmap, dumpleases, echo, ed, egrep, eject, env, envdir,
            envuidgid, ether-wake, expand, expr, factor, fakeidentd, fallocate,
            false, fatattr, fbset, fbsplash, fdflush, fdformat, fdisk,
            fgconsole, fgrep, find, findfs, flock, fold, free, freeramdisk,
            fsck, fsck.minix, fsfreeze, fstrim, fsync, ftpd, ftpget, ftpput,
            fuser, getopt, getty, grep, groups, gunzip, gzip, halt, hd, hdparm,
            head, hexdump, hexedit, hostid, hostname, httpd, hush, hwclock,
            i2cdetect, i2cdump, i2cget, i2cset, i2ctransfer, id, ifconfig,
            ifdown, ifenslave, ifup, init, insmod, install, ionice, iostat, ip,
            ipaddr, ipcalc, ipcrm, ipcs, iplink, ipneigh, iproute, iprule,
            iptunnel, kbd_mode, kill, killall, killall5, klogd, last, less,
            link, linux32, linux64, linuxrc, ln, loadfont, loadkmap, logger,
            login, logname, logread, losetup, lpd, lpq, lpr, ls, lsattr, lsmod,
            lsof, lspci, lsscsi, lsusb, lzcat, lzma, lzop, makedevs, makemime,
            man, md5sum, mdev, mesg, microcom, mim, mkdir, mkdosfs, mke2fs,
            mkfifo, mkfs.ext2, mkfs.minix, mkfs.vfat, mknod, mkpasswd, mkswap,
            mktemp, modinfo, modprobe, more, mount, mountpoint, mpstat, mt, mv,
            nameif, nanddump, nandwrite, nbd-client, nc, netstat, nice, nl,
            nmeter, nohup, nologin, nproc, nsenter, nslookup, ntpd, od, openvt,
            partprobe, passwd, paste, patch, pgrep, pidof, ping, ping6,
            pipe_progress, pivot_root, pkill, pmap, popmaildir, poweroff,
            powertop, printenv, printf, ps, pscan, pstree, pwd, pwdx,
            raidautorun, rdate, rdev, readahead, readlink, readprofile,
            realpath, reboot, reformime, remove-shell, renice, reset, resize,
            resume, rev, rm, rmdir, rmmod, route, rpm, rpm2cpio, rtcwake,
            run-init, run-parts, runlevel, runsv, runsvdir, rx, script,
            scriptreplay, sed, sendmail, seq, setarch, setconsole, setfattr,
            setfont, setkeycodes, setlogcons, setpriv, setserial, setsid,
            setuidgid, sh, sha1sum, sha256sum, sha3sum, sha512sum, showkey,
            shred, shuf, slattach, sleep, smemcap, softlimit, sort, split,
            ssl_client, start-stop-daemon, stat, strings, stty, su, sulogin,
            sum, sv, svc, svlogd, svok, swapoff, swapon, switch_root, sync,
            sysctl, syslogd, tac, tail, tar, taskset, tc, tcpsvd, tee, telnet,
            telnetd, test, tftp, tftpd, time, timeout, top, touch, tr,
            traceroute, traceroute6, true, truncate, ts, tty, ttysize, tunctl,
            ubiattach, ubidetach, ubimkvol, ubirename, ubirmvol, ubirsvol,
            ubiupdatevol, udhcpc, udhcpc6, udhcpd, udpsvd, uevent, umount,
            uname, unexpand, uniq, unix2dos, unlink, unlzma, unshare, unxz,
            unzip, uptime, users, usleep, uudecode, uuencode, vconfig, vi,
            vlock, volname, w, wall, watch, watchdog, wc, wget, which, who,
            whoami, whois, xargs, xxd, xz, xzcat, yes, zcat, zcip

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

    add-shell
        add-shell SHELL...

        Add SHELLs to /etc/shells

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

        Add a group or add a user to a group

                -g GID  Group id
                -S      Create a system group

    adduser
        adduser [OPTIONS] USER [GROUP]

        Create new user, or add USER to GROUP

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

    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

    ar  ar x|p|t [-ov] ARCHIVE [FILE]...

        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

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

        Manipulate ARP cache

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

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

        Send ARP requests/replies

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

    ash ash [-il] [-|+Cabefmnuvx] [-|+o OPT]... [-c 'SCRIPT' [ARG0 ARGS] |
        FILE [ARGS] | -s [ARGS]]

        Unix shell interpreter

    awk awk [OPTIONS] [AWK_PROGRAM] [FILE]...

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

    base32
        base32 [-d] [-w COL] [FILE]

        Base32 encode or decode FILE to standard output

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

    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]

        Strip directory path and .SUFFIX from FILE

    bc  bc [-sqlw] [FILE]...

        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

    beep
        beep -f FREQ -l LEN -d DELAY -r COUNT -n

                -f      Frequency in Hz
                -l      Length in ms
                -d      Delay in ms
                -r      Repetitions
                -n      Start new tone

    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

    bootchartd
        bootchartd start [PROG ARGS]|stop|init

        Create /var/log/bootchart.tgz with boot chart data

        start: start background logging; with PROG, run PROG, then kill
        logging with USR1 stop: send USR1 to all bootchartd processes init:
        start background logging; stop when getty/xdm is seen (for init
        scripts) Under PID 1: as init, then exec $bootchart_init, /init,
        /sbin/init

    brctl
        brctl COMMAND [BRIDGE [ARGS]]

        Manage ethernet bridges Commands:

                show [BRIDGE]...        Show bridges
                addbr BRIDGE            Create BRIDGE
                delbr BRIDGE            Delete BRIDGE
                addif BRIDGE IFACE      Add IFACE to BRIDGE
                delif BRIDGE IFACE      Delete IFACE from BRIDGE
                showmacs BRIDGE                 List MAC addresses
                showstp BRIDGE                  Show STP info
                stp BRIDGE 1/yes/on|0/no/off    Set STP on/off
                setageing BRIDGE SECONDS        Set ageing time
                setfd BRIDGE SECONDS            Set bridge forward delay
                sethello BRIDGE SECONDS         Set hello time
                setmaxage BRIDGE SECONDS        Set max message age
                setbridgeprio BRIDGE PRIO       Set bridge priority
                setportprio BRIDGE IFACE PRIO   Set port priority
                setpathcost BRIDGE IFACE COST   Set path cost

    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

    cal cal [-jy] [[MONTH] YEAR]

        Display a calendar

                -j      Use julian dates
                -y      Display the entire year

    cat cat [-nbvteA] [FILE]...

        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

    chat
        chat EXPECT [SEND [EXPECT [SEND]]...]

        Useful for interacting with a modem connected to stdin/stdout. A
        script consists of "expect-send" argument pairs. Example:

        chat '' ATZ OK ATD123456 CONNECT '' ogin: pppuser word: ppppass '~'

    chattr
        chattr [-R] [-v VERSION] [-p PROJID] [-+=AacDdijsStTu] FILE...

        Change ext2 file attributes

                -R      Recurse
                -v NUM  Set version/generation number
                -p NUM  Set project number
        Modifiers:

                -,+,=   Remove/add/set attributes
        Attributes:

                A       No atime
                a       Append only
                C       No copy-on-write
                c       Compressed
                D       Synchronous dir updates
                d       Don't backup with dump
                E       Encrypted
                e       File uses extents
                F       Case-insensitive dir
                I       Indexed dir
                i       Immutable
                j       Write data to journal first
                N       File is stored in inode
                P       Hierarchical project ID dir
                S       Synchronous file updates
                s       Zero storage when deleted
                T       Top of dir hierarchy
                t       Don't tail-merge with other files
                u       Allow undelete
                V       Verity

    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

    chpasswd
        chpasswd [-me] [-c ALG] [-R DIR]

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

                -e      Supplied passwords are in encrypted form
                -m      Encrypt using md5, not des
                -c ALG  des,md5,sha256/512 (default des)
                -R DIR  Directory to chroot into

    chpst
        chpst [-vP012] [-u USER[:GRP]] [-U USER[:GRP]] [-e DIR] [-/ DIR] [-n
        NICE] [-m BYTES] [-d BYTES] [-o N] [-p N] [-f BYTES] [-c BYTES] PROG
        ARGS

        Change the process state, run PROG

                -u USER[:GRP]   Set uid and gid
                -U USER[:GRP]   Set $UID and $GID in environment
                -e DIR          Set environment variables as specified by files
                                in DIR: file=1st_line_of_file
                -/ DIR          Chroot to DIR
                -n NICE         Add NICE to nice value
                -m BYTES        Same as -d BYTES -s BYTES -l BYTES
                -d BYTES        Limit data segment
                -o N            Limit number of open files per process
                -p N            Limit number of processes per uid
                -f BYTES        Limit output file sizes
                -c BYTES        Limit core file size
                -v              Verbose
                -P              Create new process group
                -0              Close stdin
                -1              Close stdout
                -2              Close stderr

    chroot
        chroot NEWROOT [PROG ARGS]

        Run PROG with root directory set to NEWROOT

    chrt
        chrt -m | -p [PRIO] PID | [-rfobi] PRIO PROG ARGS

        Change scheduling priority and class for a process

                -m      Show min/max priorities
                -p      Operate on PID
                -r      Set SCHED_RR class
                -f      Set SCHED_FIFO class
                -o      Set SCHED_OTHER class
                -b      Set SCHED_BATCH class
                -i      Set SCHED_IDLE class

    chvt
        chvt N

        Change the foreground virtual terminal to /dev/ttyN

    cksum
        cksum FILE...

        Calculate CRC32 checksum of FILEs

    clear
        clear

        Clear screen

    cmp cmp [-ls] 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

    comm
        comm [-123] FILE1 FILE2

        Compare FILE1 with FILE2

                -1      Suppress lines unique to FILE1
                -2      Suppress lines unique to FILE2
                -3      Suppress lines common to both files

    conspy
        conspy [-vcsndfFQ] [-x COL] [-y LINE] [CONSOLE_NO]

        A text-mode VNC like program for Linux virtual consoles. To exit,
        quickly press ESC 3 times.

                -v      Don't send keystrokes to the console
                -c      Create missing /dev/{tty,vcsa}N
                -s      Open a SHELL session
                -n      Black & white
                -d      Dump console to stdout
                -f      Follow cursor
                -F      Assume console is on a framebuffer device
                -Q      Disable exit on ESC-ESC-ESC
                -x COL  Starting column
                -y LINE Starting line

    cp  cp [-arPLHpfinlsTu] SOURCE DEST or: cp [-arPLHpfinlsu] SOURCE... {
        -t DIRECTORY | DIRECTORY }

        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] [-p DIR]
        [EXTR_FILE]...

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

        Main operation mode:

                -t      List
                -i      Extract EXTR_FILEs (or all)
                -o      Create (requires -H newc)
                -p DIR  Copy files to DIR
        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      Input is separated by NULs

    crc32
        crc32 FILE...

        Calculate CRC32 checksum of FILEs

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

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

    cryptpw
        cryptpw [-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 des)
                -S SALT

    cttyhack
        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 cut [OPTIONS] [FILE]...

        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 delimeter for output (default = -d for -f, one space for -F)
                -D      Don't sort/collate sections or match -fF lines without delimeter
                -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

    dc  dc [-x] [-eSCRIPT]... [-fFILE]... [FILE]...

        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

    dd  dd [if=FILE] [of=FILE] [ibs=N obs=N/bs=N] [count=N] [skip=N]
        [seek=N] [conv=notrunc|noerror|sync|fsync]
        [iflag=skip_bytes|count_bytes|fullblock|direct]
        [oflag=seek_bytes|append|direct]

        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

    delgroup
        delgroup [USER] GROUP

        Delete group GROUP from the system or user USER from group GROUP

    deluser
        deluser [--remove-home] USER

        Delete USER from the system

    depmod
        depmod [-n]

        Generate modules.dep.bb

                -n      Dry run: print file 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

    df  df [-PkmhTai] [-B SIZE] [-t TYPE] [FILESYSTEM]...

        Print filesystem usage statistics

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

    dhcprelay
        dhcprelay CLIENT_IFACE[,CLIENT_IFACE2]... SERVER_IFACE [SERVER_IP]

        Relay DHCP requests between clients and server

    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

    dnsd
        dnsd [-dvs] [-c CONFFILE] [-t TTL_SEC] [-p PORT] [-i ADDR]

        Small static DNS server daemon

                -c FILE Config file
                -t SEC  TTL
                -p PORT Listen on PORT
                -i ADDR Listen on ADDR
                -d      Daemonize
                -v      Verbose
                -s      Send successful replies only. Use this if you want
                        to use /etc/resolv.conf with two nameserver lines:
                                nameserver DNSD_SERVER
                                nameserver NORMAL_DNS_SERVER

    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

    du  du [-aHLdclsxhmk] [FILE]...

        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)

    ed  ed [FILE]

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

        Eject DEVICE or default /dev/cdrom

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

    env env [-i0] [-u NAME]... [-] [NAME=VALUE]... [PROG ARGS]

        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

    envdir
        envdir DIR PROG ARGS

        Set various environment variables as specified by files in the
        directory DIR, run PROG

    envuidgid
        envuidgid USER PROG ARGS

        Set $UID to USER's uid and $GID to USER's gid, run PROG

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

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

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

    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

    fakeidentd
        fakeidentd [-fiw] [-b ADDR] [STRING]

        Provide fake ident (auth) service

                -f      Run in foreground
                -i      Inetd mode
                -w      Inetd 'wait' mode
                -b ADDR Bind to specified address
                STRING  Ident answer string (default: nobody)

    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

    fbset
        fbset [OPTIONS] [MODE]

        Show and modify frame buffer settings

    fbsplash
        fbsplash -s IMGFILE [-c] [-d DEV] [-i INIFILE] [-f CMD]

                -s      Image
                -c      Hide cursor
                -d      Framebuffer device (default /dev/fb0)
                -i      Config file (var=value):
                                BAR_LEFT,BAR_TOP,BAR_WIDTH,BAR_HEIGHT
                                BAR_R,BAR_G,BAR_B,IMG_LEFT,IMG_TOP
                -f      Control pipe (else exit after drawing image)
                                commands: 'NN' (% for progress bar) or 'exit'

    fdflush
        fdflush DEVICE

        Force floppy disk drive to detect disk change

    fdformat
        fdformat [-n] DEVICE

        Format floppy disk

                -n      Don't verify after format

    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

    fgconsole
        fgconsole

        Get active console

    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
                -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
                -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
                -delete         Delete current file/directory. Turns on -depth option
                -quit           Exit

    findfs
        findfs LABEL=label or UUID=uuid

        Find a filesystem device based on a label or UUID

    flock
        flock [-sxun] FD | { FILE [-c] PROG ARGS }

        [Un]lock file descriptor, or lock FILE, run PROG

                -s      Shared lock
                -x      Exclusive lock (default)
                -u      Unlock FD
                -n      Fail rather than wait

    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

    fsck
        fsck [-ANPRTV] [-t FSTYPE] [FS_OPTS] [BLOCKDEV]...

        Check and repair filesystems

                -A      Walk /etc/fstab and check all filesystems
                -N      Don't execute, just show what would be done
                -P      With -A, check filesystems in parallel
                -R      With -A, skip the root filesystem
                -T      Don't show title on startup
                -V      Verbose
                -t TYPE List of filesystem types to check

    fsck.minix
        fsck.minix [-larvsmf] BLOCKDEV

        Check MINIX filesystem

                -l      List all filenames
                -r      Perform interactive repairs
                -a      Perform automatic repairs
                -v      Verbose
                -s      Output superblock information
                -m      Show "mode not cleared" warnings
                -f      Force file system check

    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

    fsync
        fsync [-d] FILE...

        Write all buffered blocks in FILEs to disk

                -d      Avoid syncing metadata

    ftpd
        ftpd [-wvS] [-a USER] [-t SEC] [-T SEC] [DIR]

        FTP server. Chroots to DIR, if this fails (run by non-root), cds to
        it. It is an inetd service, inetd.conf line: 21 stream tcp nowait
        root ftpd ftpd /files/to/serve Can be run from tcpsvd:

                tcpsvd -vE 0.0.0.0 21 ftpd /files/to/serve

                -w      Allow upload
                -A      No login required, client access occurs under ftpd's UID
                -a USER Enable 'anonymous' login and map it to USER
                -v      Log errors to stderr. -vv: verbose log
                -S      Log errors to syslog. -SS: verbose log
                -t,-T N Idle and absolute timeout

    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

    fuser
        fuser [-msk46] [-SIGNAL] FILE or PORT/PROTO

        Find processes which use FILEs or PORTs

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

    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:

        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

    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 [-HhnlLoqvsrRiwFE] [-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
                -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

    hd  hd FILE...

        hd is an alias for hexdump -C

    hdparm
        hdparm [OPTIONS] [DEVICE]

                -a      Get/set fs readahead
                -A      Set drive read-lookahead flag (0/1)
                -b      Get/set bus state (0 == off, 1 == on, 2 == tristate)
                -B      Set Advanced Power Management setting (1-255)
                -c      Get/set IDE 32-bit IO setting
                -C      Check IDE power mode status
                -d      Get/set using_dma flag
                -D      Enable/disable drive defect-mgmt
                -f      Flush buffer cache for device on exit
                -g      Display drive geometry
                -h      Display terse usage information
                -i      Display drive identification
                -I      Detailed/current information directly from drive
                -k      Get/set keep_settings_over_reset flag (0/1)
                -K      Set drive keep_features_over_reset flag (0/1)
                -L      Set drive doorlock (0/1) (removable harddisks only)
                -m      Get/set multiple sector count
                -n      Get/set ignore-write-errors flag (0/1)
                -p      Set PIO mode on IDE interface chipset (0,1,2,3,4,...)
                -P      Set drive prefetch count
                -Q      Get/set DMA tagged-queuing depth (if supported)
                -r      Get/set readonly flag (DANGEROUS to set)
                -R      Register an IDE interface (DANGEROUS)
                -S      Set standby (spindown) timeout
                -t      Perform device read timings
                -T      Perform cache read timings
                -u      Get/set unmaskirq flag (0/1)
                -U      Unregister an IDE interface (DANGEROUS)
                -v      Defaults; same as -mcudkrag for IDE drives
                -V      Display program version and exit immediately
                -w      Perform device reset (DANGEROUS)
                -W      Set drive write-caching flag (0/1) (DANGEROUS)
                -x      Tristate device for hotswap (0/1) (DANGEROUS)
                -X      Set IDE xfer mode (DANGEROUS)
                -y      Put IDE drive in standby mode
                -Y      Put IDE drive to sleep
                -Z      Disable Seagate auto-powersaving mode
                -z      Reread partition table

    head
        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

    hexedit
        hexedit FILE

        Edit FILE in hexadecimal

    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              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

    hush
        hush [-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]

        Unix shell interpreter

    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

    id  id [-ugGnr] [USER]

        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

    ifenslave
        ifenslave [-cdf] MASTER_IFACE SLAVE_IFACE...

        Configure network interfaces for parallel routing

                -c      Change active slave
                -d      Remove slave interface from bonding device
                -f      Force, even if interface is not Ethernet

    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

    iostat
        iostat [-c] [-d] [-t] [-z] [-k|-m] [ALL|BLOCKDEV...] [INTERVAL
        [COUNT]]

        Report CPU and I/O statistics

                -c      Show CPU utilization
                -d      Show device utilization
                -t      Print current time
                -z      Omit devices with no activity
                -k      Use kb/s
                -m      Use Mb/s

    ip  ip [OPTIONS] address|route|link|tunnel|neigh|rule [ARGS]

        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] 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

    ipaddr
        ipaddr add|del IFADDR dev IFACE | show|flush [dev IFACE] [to PREFIX]

        ipaddr add|change|replace|delete dev IFACE [CONFFLAG-LIST] IFADDR
        IFADDR := PREFIX | ADDR peer PREFIX [broadcast ADDR|+|-] [anycast
        ADDR] [label STRING] [scope SCOPE] PREFIX := ADDR[/MASK] SCOPE :=
        [host|link|global|NUMBER] CONFFLAG-LIST := [CONFFLAG-LIST] CONFFLAG
        CONFFLAG := [noprefixroute] ipaddr show|flush [dev IFACE] [scope
        SCOPE] [to PREFIX] [label PATTERN]

    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

    ipcrm
        ipcrm [-MQS key] [-mqs id]

        Upper-case options MQS remove an object by shmkey value. Lower-case
        options remove an object by shmid value.

                -mM     Remove memory segment after last detach
                -qQ     Remove message queue
                -sS     Remove semaphore

    ipcs
        ipcs [[-smq] -i SHMID] | [[-asmq] [-tcplu]]

                -i ID   Show specific resource
        Resource specification:

                -m      Shared memory segments
                -q      Message queues
                -s      Semaphore arrays
                -a      All (default)
        Output format:

                -t      Time
                -c      Creator
                -p      Pid
                -l      Limits
                -u      Summary

    iplink
        iplink set IFACE [up|down] [arp on|off] [multicast on|off] [promisc
        on|off] [mtu NUM] [name NAME] [qlen NUM] [address MAC] [master IFACE
        | nomaster] iplink add [link IFACE] IFACE [address MAC] type TYPE
        [ARGS] iplink delete IFACE type TYPE [ARGS] TYPE ARGS := vlan
        VLANARGS | vrf table NUM VLANARGS := id VLANID [protocol
        802.1q|802.1ad] [reorder_hdr on|off] [gvrp on|off] [mvrp on|off]
        [loose_binding on|off] iplink show [IFACE]

    ipneigh
        ipneigh show|flush [to PREFIX] [dev DEV] [nud STATE]

    iproute
        iproute list|flush|add|del|change|append|replace|test ROUTE

        iproute list|flush SELECTOR SELECTOR := [root PREFIX] [match PREFIX]
        [proto RTPROTO] PREFIX := default|ADDR[/MASK] iproute get ADDR [from
        ADDR iif IFACE] [oif IFACE] [tos TOS] iproute
        add|del|change|append|replace|test ROUTE ROUTE := NODE_SPEC
        [INFO_SPEC] NODE_SPEC := PREFIX [table TABLE_ID] [proto RTPROTO]
        [scope SCOPE] [metric METRIC] INFO_SPEC := NH OPTIONS NH := [via
        [inet|inet6] ADDR] [dev IFACE] [src ADDR] [onlink] OPTIONS := [mtu
        [lock] NUM] [advmss [lock] NUM]

    iprule
        iprule [list] | add|del SELECTOR ACTION

                SELECTOR := [from PREFIX] [to PREFIX] [tos TOS] [fwmark FWMARK[/MASK]]
                                [dev IFACE] [pref NUMBER]
                ACTION := [table TABLE_ID] [nat ADDR]
                                [prohibit|reject|unreachable]
                                [realms [SRCREALM/]DSTREALM]
                TABLE_ID := [local|main|default|NUMBER]

    iptunnel
        iptunnel add|change|del|show [NAME] [mode ipip|gre|sit] [remote
        ADDR] [local ADDR] [ttl TTL]

        iptunnel add|change|del|show [NAME] [mode ipip|gre|sit] [remote
        ADDR] [local ADDR] [[i|o]seq] [[i|o]key KEY] [[i|o]csum] [ttl TTL]
        [tos TOS] [[no]pmtudisc] [dev PHYS_DEV]

    kbd_mode
        kbd_mode [-a|k|s|u] [-C TTY]

        Report or set VT console keyboard mode

                -a      Default (ASCII)
                -k      Medium-raw (keycode)
                -s      Raw (scancode)
                -u      Unicode (utf-8)
                -C TTY  Affect TTY

    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

    killall5
        killall5 [-l] [-SIG] [-o PID]...

        Send a signal (default: TERM) to all processes outside current
        session

                -l      List all signal names and numbers
                -o PID  Don't signal this PID

    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 [-HW] [-f FILE]

        Show listing of the last users that logged into the system

                -W      Display with no host column truncation
                -f FILE Read from FILE instead of /var/log/wtmp

    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

    ln  ln [-sfnbtv] [-S SUF] TARGET... LINK|DIR

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

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

        $LOGIN_TIMEOUT Seconds (default 60, 0 - disable)
        $LOGIN_PRE_SUID_SCRIPT Execute before user ID change

    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
        losetup [-rP] [-o OFS] {-f|LOOPDEV} FILE: associate loop devices
        losetup -c LOOPDEV: reread file size losetup -d LOOPDEV:
        disassociate losetup -a: show status losetup -f: show next free loop
        device

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

    lpd lpd SPOOLDIR [HELPER [ARGS]]

        SPOOLDIR must contain (symlinks to) device nodes or directories with
        names matching print queue names. In the first case, jobs are sent
        directly to the device. Otherwise each job is stored in queue
        directory and HELPER program is called. Name of file to print is
        passed in $DATAFILE variable. Example:

                tcpsvd -E 0 515 softlimit -m 999999 lpd /var/spool ./print

    lpq lpq [-P queue[@host[:port]]] [-U USERNAME] [-d JOBID]... [-fs]

                -P      lp service to connect to (else uses $PRINTER)
                -d      Delete jobs
                -f      Force any waiting job to be printed
                -s      Short display

    lpr lpr -P queue[@host[:port]] -U USERNAME -J TITLE -Vmh [FILE]...

                -P      lp service to connect to (else uses $PRINTER)
                -m      Send mail on completion
                -h      Print banner page too
                -V      Verbose

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

        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}]

    lsattr
        lsattr [-Radlpv] [FILE]...

        List ext2 file attributes

                -R      Recurse
                -a      Include names starting with .
                -d      List directory names, not contents
                -l      List long flag names
                -p      List project ID
                -v      List version/generation number

    lsmod
        lsmod

        List loaded kernel modules

    lsof
        lsof

        Show all open files

    lspci
        lspci [-mk]

        List all PCI devices

                -m      Parsable output
                -k      Show driver

    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

    makedevs
        makedevs [-d device_table] rootdir

        Create a range of special files as specified in a device table.
        Device table entries take the form of:

        <name> <type> <mode> <uid> <gid> <major> <minor> <start> <inc>
        <count> Where name is the file name, type can be one of: f Regular
        file d Directory c Character device b Block device p Fifo (named
        pipe) uid is the user id for the target file, gid is the group id
        for the target file. The rest of the entries (major, minor, etc)
        apply to to device special files. A '-' may be used for blank
        entries.

    makemime
        makemime [OPTIONS] [FILE]...

        Create multipart MIME-encoded message from FILEs

                -o FILE Output. Default: stdout
                -a HDR  Add header(s). Examples:
                        "From: user@host.org", "Date: `date -R`"
                -c CT   Content type. Default: application/octet-stream
                -C CS   Charset. Default: us-ascii

        Other options are silently ignored

    man man [-aw] [SECTION] MANPAGE[.SECTION]...

        Display manual page

                -a      Display all pages
                -w      Show page locations

        $COLUMNS overrides output width

    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      stay in foreground

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

        It uses /etc/mdev.conf with lines [-][ENV=regex;]...DEVNAME UID:GID
        PERM [>|=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.

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

    mesg
        mesg [y|n]

        Control write access to your terminal y Allow write access to your
        terminal n Disallow write access to your terminal

    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

    mim mim [-f FILE] [SHELL_OPTIONS] [TARGET] ...

        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)

    mkfs.ext2
        mkfs.ext2 [-Fn] [-b BLK_SIZE] [-i INODE_RATIO] [-I INODE_SIZE] [-m
        RESERVED_PERCENT] [-L LABEL] BLOCKDEV [KBYTES]

                -b BLK_SIZE     Block size, bytes
                -F              Force
                -i RATIO        Max number of files is filesystem_size / RATIO
                -I BYTES        Inode size (min 128)
                -L LBL          Volume label
                -m PERCENT      Percent of blocks to reserve for admin
                -n              Dry run

    mkfs.minix
        mkfs.minix [-c | -l FILE] [-nXX] [-iXX] BLOCKDEV [KBYTES]

        Make a MINIX filesystem

                -c              Check device for bad blocks
                -n [14|30]      Maximum length of filenames
                -i INODES       Number of inodes for the filesystem
                -l FILE         Read bad blocks list from FILE
                -v              Make version 2 filesystem

    mkfs.vfat
        mkfs.vfat [-v] [-n LABEL] BLOCKDEV [KBYTES]

        Make a FAT32 filesystem

                -v      Verbose
                -n LBL  Volume label

    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 des)
                -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 [-rq] MODULE [SYMBOL=VALUE]...

                -r      Remove MODULE
                -q      Quiet

    more
        more [FILE]...

        View FILE (or stdin) one screenful at a time

    mount
        mount [OPTIONS] [-o OPT] DEVICE NODE

        Mount a filesystem. Filesystem autodetection requires /proc.

                -a              Mount all filesystems in fstab
                -f              Dry run
                -v              Verbose
                -r              Read-only mount
                -t FSTYPE[,...] Filesystem type(s)
                -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.

    mountpoint
        mountpoint [-q] { [-dn] DIR | -x DEVICE }

        Check if DIR is a mountpoint

                -q      Quiet
                -d      Print major:minor of the filesystem
                -n      Print device name of the filesystem
                -x      Print major:minor of DEVICE

    mpstat
        mpstat [-A] [-I SUM|CPU|ALL|SCPU] [-u] [-P num|ALL] [INTERVAL
        [COUNT]]

        Per-processor statistics

                -A                      Same as -I ALL -u -P ALL
                -I SUM|CPU|ALL|SCPU     Report interrupt statistics
                -P num|ALL              Processor to monitor
                -u                      Report CPU utilization

    mt  mt [-f DEVICE] OPCODE VALUE

        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

    mv  mv [-finT] SOURCE DEST or: mv [-fin] SOURCE... { -t DIRECTORY |
        DIRECTORY }

        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 SELECTOR]...

        Rename network interface while it in the down state. The device
        matched by SELECTOR is renamed to IFNAME. SELECTOR can be a
        combination of:

                driver=STRING
                bus=STRING
                phy_address=NUM
                [mac=]XX:XX:XX:XX:XX:XX

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

    nanddump
        nanddump [-no] [--bb padbad|skipbad] [-s ADDR] [-l LEN] [-f FILE]
        MTD_DEVICE

        Dump MTD_DEVICE

                -n      Read without ecc
                -o      Dump oob data
                -s ADDR Start address
                -l LEN  Length
                -f FILE Dump to file ('-' for stdout)
                --bb METHOD
                        skipbad: skip bad blocks
                        padbad: substitute bad blocks by 0xff (default)

    nandwrite
        nandwrite [-np] [-s ADDR] MTD_DEVICE [FILE]

        Write to MTD_DEVICE

                -n      Write without ecc
                -p      Pad to page size
                -s ADDR Start address

    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

    nc  nc [OPTIONS] HOST PORT - connect nc [OPTIONS] -l -p PORT [HOST]
        [PORT] - listen

                -e PROG Run PROG after connect (must be last)
                -l      Listen mode, for inbound connects
                -lk     With -e, provides persistent server
                -p PORT Local port
                -s ADDR Local address
                -w SEC  Timeout for connects and final net reads
                -i SEC  Delay interval for lines sent
                -n      Don't do DNS resolution
                -u      UDP mode
                -b      Allow broadcasts
                -v      Verbose
                -o FILE Hex dump traffic
                -z      Zero-I/O mode (scanning)

    netstat
        netstat [-ral] [-tuwx] [-enWp]

        Display networking information

                -r      Routing table
                -a      All sockets
                -l      Listening sockets
                        Else: connected sockets
                -t      TCP sockets
                -u      UDP sockets
                -w      Raw sockets
                -x      Unix sockets
                        Else: all socket types
                -e      Other/more information
                -n      Don't resolve names
                -W      Wide display
                -p      Show PID/program name for sockets

    nice
        nice [-n ADJUST] [PROG ARGS]

        Change scheduling priority, run PROG

                -n ADJUST       Adjust priority by ADJUST

    nl  nl [OPTIONS] [FILE]...

        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

    nmeter
        nmeter [-d MSEC] FORMAT_STRING

        Monitor system in real time

         -d MSEC        Milliseconds between updates, default:1000, none:-1

        Format specifiers:

         %Nc or %[cN]   CPU. N - bar size (default 10)
                        (displays: S:system U:user N:niced D:iowait I:irq i:softirq)
         %[nINTERFACE]  Network INTERFACE
         %m             Allocated memory
         %[mf]          Free memory
         %[mt]          Total memory
         %s             Allocated swap
         %f             Number of used file descriptors
         %Ni            Total/specific IRQ rate
         %x             Context switch rate
         %p             Forks
         %[pn]          # of processes
         %b             Block io
         %Nt            Time (with N decimal points)
         %NT            Zero-based timestamp (with N decimal points)
         %r             Print <cr> instead of <lf> at EOL

    nohup
        nohup PROG ARGS

        Run PROG immune to hangups, with output to a non-tty

    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

    ntpd
        ntpd [-dnqNwl] [-I IFACE] [-S PROG] [-k KEYFILE] [-p
        [keyno:N:]PEER]...

        NTP client/server

                -d[d]   Verbose
                -n      Do not daemonize
                -q      Quit after clock is set
                -N      Run at high priority
                -w      Do not set time (only query peers), implies -n
                -S PROG Run PROG after stepping time, stratum change, and every 11 min
                -k FILE Key file (ntp.keys compatible)
                -p [keyno:NUM:]PEER
                        Obtain time from PEER (may be repeated)
                        Use key NUM for authentication
                        If -p is not given, 'server HOST' lines
                        from /etc/ntp.conf are used
                -l      Also run as server on port 123
                -I IFACE Bind server to IFACE, implies -l

    od  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
        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 des)
                -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

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

        Display process(es) selected by regex PATTERN

                -l      Show command name too
                -a      Show command line too
                -f      Match against entire command line
                -n      Show the newest process only
                -o      Show the oldest process only
                -v      Negate the match
                -x      Match whole name (not substring)
                -s      Match session ID (0 for current)
                -P      Match parent process ID

    pidof
        pidof [-s] [-o PID] [NAME]...

        List PIDs of all processes with names that match NAMEs

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

    ping
        ping [OPTIONS] HOST

        Send ICMP ECHO_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 recevied
                -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 recevied
                -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

    pkill
        pkill [-l|-SIGNAL] [-xfvno] [-s SID|-P PPID|PATTERN]

        Send signal to processes selected by regex PATTERN

                -l      List all signals
                -x      Match whole name (not substring)
                -f      Match against entire command line
                -s SID  Match session ID (0 for current)
                -P PPID Match parent process ID
                -v      Negate the match
                -n      Signal the newest process only
                -o      Signal the oldest process only

    pmap
        pmap [-xq] PID...

        Display process memory usage

                -x      Show details
                -q      Quiet

    popmaildir
        popmaildir [OPTIONS] MAILDIR [CONN_HELPER ARGS]

        Fetch content of remote mailbox to local maildir

                -s              Skip authorization
                -T              Get messages with TOP instead of RETR
                -k              Keep retrieved messages on the server
                -t SEC          Network timeout
                -F 'PROG ARGS'  Filter program (may be repeated)
                -M 'PROG ARGS'  Delivery program

        Fetch from plain POP3 server: popmaildir -k DIR nc pop3.server.com
        110 <user_and_pass.txt Fetch from SSLed POP3 server and delete
        fetched emails: popmaildir DIR -- openssl s_client -quiet -connect
        pop3.server.com:995 <user_and_pass.txt

    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)

    powertop
        powertop

        Analyze power consumption on Intel-based laptops

    printenv
        printenv [VARIABLE]...

        Print environment VARIABLEs. If no VARIABLE specified, print all.

    printf
        printf FORMAT [ARG]...

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

    ps  ps [-o COL1,COL2=HEADER] [-T]

        Show list of processes

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

    pscan
        pscan [-cb] [-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT]
        HOST

        Scan HOST, print all open ports

                -c      Show closed ports too
                -b      Show blocked ports too
                -p PORT Scan from this port (default 1)
                -P PORT Scan up to this port (default 1024)
                -t MS   Timeout (default 5000 ms)
                -T MS   Minimum rtt (default 5 ms)

    pstree
        pstree [-p] [PID|USER]

        Display process tree, optionally start from USER or PID

                -p      Show pids

    pwd pwd

        Print the full filename of the current working directory

    pwdx
        pwdx PID...

        Show current directory for PIDs

    raidautorun
        raidautorun DEVICE

        Tell the kernel to automatically search and start RAID arrays

    rdate
        rdate [-s/-p] HOST

        Set and print time from HOST using RFC 868

                -s      Only set system time
                -p      Only print time

    rdev
        rdev

        Print the device node associated with the filesystem mounted at '/'

    readahead
        readahead [FILE]...

        Preload FILEs to RAM

    readlink
        readlink [-fnv] FILE

        Display the value of a symlink

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

    readprofile
        readprofile [OPTIONS]

                -m MAPFILE      (Default: /boot/System.map)
                -p PROFILE      (Default: /proc/profile)
                -M NUM          Set the profiling multiplier to NUM
                -i              Print only info about the sampling step
                -v              Verbose
                -a              Print all symbols, even if count is 0
                -b              Print individual histogram-bin counts
                -s              Print individual counters within functions
                -r              Reset all the counters (root only)
                -n              Disable byte order auto-detection

    realpath
        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)

    reformime
        reformime [OPTIONS]

        Parse MIME-encoded message on stdin

                -x PREFIX       Extract content of MIME sections to files
                -X PROG ARGS    Filter content of MIME sections through PROG
                                Must be the last option

        Other options are silently ignored

    remove-shell
        remove-shell SHELL...

        Remove SHELLs from /etc/shells

    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 the screen

    resize
        resize

        Resize the screen

    resume
        resume BLOCKDEV [OFFSET]

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

    rev rev [FILE]...

        Reverse lines of FILE

    rm  rm [-irf] 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 MODULE...

        Unload kernel modules

    route
        route [-ne] [-A inet[6]] [{add|del} [-net|-host] TARGET [netmask
        MASK] [gw GATEWAY] [metric N] [mss BYTES] [window BYTES] [reject]
        [IFACE]]

        Show or edit kernel routing tables

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

    rpm rpm -i PACKAGE.rpm; rpm -qp[ildc] PACKAGE.rpm

        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

    rtcwake
        rtcwake [-a | -l | -u] [-d DEV] [-m MODE] [-s SEC | -t TIME]

        Enter a system sleep state until specified wakeup time

                -a      Read clock mode from /etc/adjtime (default)
                -l      Clock is set to local time
                -u      Clock is set to UTC time
                -d DEV  Specify the RTC device
                -m MODE Set sleep state (default: standby)
                -s SEC  Set timeout in SEC seconds from now
                -t TIME Set timeout to TIME seconds from epoch

    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] [--list] 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
                --list          Print names of matching files even if they are not executable

    runlevel
        runlevel [FILE]

        Find the current and previous system runlevel

        If no utmp FILE exists or if no runlevel record can be found, print
        "unknown"

    runsv
        runsv DIR

        Start and monitor a service and optionally an appendant log service

    runsvdir
        runsvdir [-P] [-s SCRIPT] DIR

        Start a runsv process for each subdirectory. If it exits, restart
        it.

                -P              Put each runsv in a new session
                -s SCRIPT       Run SCRIPT <signo> after signal is processed

    rx  rx FILE

        Receive a file using the xmodem protocol

    script
        script [-afq] [-t[FILE]] [-c PROG] [OUTFILE]

        Default OUTFILE is 'typescript'

                -a      Append output
                -c PROG Run PROG, not shell
                -q      Quiet
                -t[FILE] Send timing to stderr or FILE

    scriptreplay
        scriptreplay TIMINGFILE [TYPESCRIPT [DIVISOR]]

        Play back typescripts, using timing information

    sed sed [-i[SFX]] [-nrE] [-f FILE]... [-e CMD]... [FILE]... or: sed
        [-i[SFX]] [-nrE] CMD [FILE]...

                -e CMD  Add CMD to sed commands to be executed
                -f FILE Add FILE contents to sed commands to be executed
                -i[SFX] Edit files in-place (otherwise 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).

    sendmail
        sendmail [-tv] [-f SENDER] [-amLOGIN 4<user_pass.txt | -auUSER
        -apPASS] [-w SECS] [-H 'PROG ARGS' | -S HOST] [RECIPIENT_EMAIL]...

        Read email from stdin and send it

        Standard options:

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

        Busybox specific options:

                -v              Verbose
                -w SECS         Network timeout
                -H 'PROG ARGS'  Run connection helper. Examples:
                        openssl s_client -quiet -tls1 -starttls smtp -connect smtp.gmail.com:25
                        openssl s_client -quiet -tls1 -connect smtp.gmail.com:465
                                $SMTP_ANTISPAM_DELAY: seconds to wait after helper connect
                -S HOST[:PORT]  Server (default $SMTPHOST or 127.0.0.1)
                -amLOGIN        Log in using AUTH LOGIN
                -amPLAIN        or AUTH PLAIN
                                (-amCRAM-MD5 not supported)
                -auUSER         Username for AUTH
                -apPASS         Password for AUTH

        If no -a options are given, authentication is not done. If -amLOGIN
        is given but no -au/-ap, user/password is read from fd #4. Other
        options are silently ignored; -oi is implied. Use makemime to create
        emails with attachments.

    seq seq [-w] [-s SEP] [FIRST [INC]] LAST

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

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

    setarch
        setarch PERSONALITY [-R] PROG ARGS

        PERSONALITY may be:

                linux32 Set 32bit uname emulation
                linux64 Set 64bit uname emulation

                -R      Disable address space randomization

    setconsole
        setconsole [-r] [DEVICE]

        Make writes to /dev/console appear on DEVICE (default: /dev/tty).
        Does not redirect kernel log output or reads from /dev/console.

                -r      Reset: writes to /dev/console go to kernel log tty(s)

    setfattr
        setfattr [-h] -n|-x ATTR [-v VALUE] FILE...

        Set extended attributes

                -h              Do not follow symlinks
                -x ATTR         Remove attribute ATTR
                -n ATTR         Set attribute ATTR to VALUE
                -v VALUE        (default: empty)

    setfont
        setfont [-m MAPFILE] [-C TTY] FILE

        Load a console font

                -m MAPFILE      Load console screen map
                -C TTY          Affect TTY instead of /dev/tty

    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.

    setlogcons
        setlogcons [N]

        Pin kernel output to VT console N. Default:0 (do not pin)

    setpriv
        setpriv [OPTIONS] PROG ARGS

        Run PROG with different privilege settings

        -d,--dump Show current capabilities --nnp,--no-new-privs Ignore
        setuid/setgid bits and file capabilities --inh-caps CAP,CAP Set
        inheritable capabilities --ambient-caps CAP,CAP Set ambient
        capabilities

    setserial
        setserial [-abGvz] { DEVICE [PARAMETER [ARG]]... | -g DEVICE... }

        Print or set serial port parameters

                -a      Print all
                -b      Print summary
                -G      Print as setserial PARAMETERs
                -v      Verbose
                -z      Zero out serial flags before setting
                -g      All args are device names

        PARAMETERs: (* = takes ARG, ^ = can be turned off by preceding ^)
        *port, *irq, *divisor, *uart, *baud_base, *close_delay,
        *closing_wait, ^fourport, ^auto_irq, ^skip_test, ^sak,
        ^session_lockout, ^pgrp_lockout, ^callout_nohup, ^split_termios,
        ^hup_notify, ^low_latency, autoconfig, spd_normal, spd_hi, spd_vhi,
        spd_shi, spd_warp, spd_cust ARG for uart:

                unknown, 8250, 16450, 16550, 16550A, Cirrus, 16650, 16650V2, 16750,
                16950, 16954, 16654, 16850, RSA, NS16550A, XSCALE, RM9000, OCTEON, AR7,
                U6_16550A

    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

    setuidgid
        setuidgid USER PROG ARGS

        Set uid and gid to USER's uid and gid, drop supplementary group ids,
        run PROG

    sh  sh [-il] [-|+Cabefmnuvx] [-|+o OPT]... [-c 'SCRIPT' [ARG0 ARGS] |
        FILE [ARGS] | -s [ARGS]]

        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

    showkey
        showkey [-a | -k | -s]

        Show keys pressed

                -a      Display decimal/octal/hex values of the keys
                -k      Display interpreted keycodes (default)
                -s      Display raw scan-codes

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

        Randomly permute lines

                -e      Treat ARGs as lines
                -i L-H  Treat numbers L-H as lines
                -n NUM  Output at most NUM lines
                -o FILE Write to FILE, not standard output
                -z      End lines with zero byte, not newline

    slattach
        slattach [-ehmLF] [-c SCRIPT] [-s BAUD] [-p PROTOCOL] SERIAL_DEVICE

        Configure serial line as SLIP network interface

                -p PROT Protocol: slip, cslip (default), slip6, clisp6, adaptive
                -s BAUD Line speed
                -e      Exit after initialization
                -h      Exit if carrier is lost (else never exits)
                -c PROG Run PROG on carrier loss
                -m      Do NOT set raw 8bit mode
                -L      Enable 3-wire operation
                -F      Disable RTS/CTS flow control

    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

    smemcap
        smemcap >SMEMDATA.TAR

        Collect memory usage data in /proc and write it to stdout

    softlimit
        softlimit [-a BYTES] [-m BYTES] [-d BYTES] [-s BYTES] [-l BYTES] [-f
        BYTES] [-c BYTES] [-r BYTES] [-o N] [-p N] [-t N] PROG ARGS

        Set soft resource limits, then run PROG

                -a BYTES        Limit total size of all segments
                -m BYTES        Same as -d BYTES -s BYTES -l BYTES -a BYTES
                -d BYTES        Limit data segment
                -s BYTES        Limit stack segment
                -l BYTES        Limit locked memory size
                -o N            Limit number of open files per process
                -p N            Limit number of processes per uid
        Options controlling file sizes:

                -f BYTES        Limit output file sizes
                -c BYTES        Limit core file size
        Efficiency opts:

                -r BYTES        Limit resident set size
                -t N            Limit CPU time, process receives
                                a SIGXCPU after N seconds

    sort
        sort [-nrugMcszbdfiokt] [-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
                -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

    split
        split [OPTIONS] [INPUT [PREFIX]]

                -b N[k|m]       Split by N (kilo|mega)bytes
                -l N            Split by N lines
                -a N            Use N letters as suffix

    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

    su  su [-lmp] [-s SH] [-] [USER [FILE ARGS | -c 'CMD' [ARG0 ARGS]]]

        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

                -t N    Timeout

    sum sum [-rs] [FILE]...

        Checksum and count the blocks in a file

                -r      Use BSD sum algorithm (1K blocks)
                -s      Use System V sum algorithm (512byte blocks)

    sv  sv [-v] [-w SEC] CMD SERVICE_DIR...

        Control services monitored by runsv supervisor. Commands (only first
        character is enough):

        status: query service status up: if service isn't running, start it.
        If service stops, restart it once: like 'up', but if service stops,
        don't restart it down: send TERM and CONT signals. If ./run exits,
        start ./finish if it exists. After it stops, don't restart service
        exit: send TERM and CONT signals to service and log service. If they
        exit, runsv exits too pause, cont, hup, alarm, interrupt, quit, 1,
        2, term, kill: send STOP, CONT, HUP, ALRM, INT, QUIT, USR1, USR2,
        TERM, KILL signal to service

    svc svc [-udopchaitkx] SERVICE_DIR...

        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

    svlogd
        svlogd [-tttv] [-r C] [-R CHARS] [-l MATCHLEN] [-b BUFLEN] DIR...

        Read log data from stdin and write to rotated log files in DIRs

                -r C    Replace non-printable characters with C
                -R CHARS Also replace CHARS with C (default _)
                -t      Timestamp with @tai64n
                -tt     Timestamp with yyyy-mm-dd_hh:mm:ss.sssss
                -ttt    Timestamp with yyyy-mm-ddThh:mm:ss.sssss
                -v      Verbose

        DIR/config file modifies behavior: sSIZE - when to rotate logs
        (default 1000000, 0 disables) nNUM - number of files to retain !PROG
        - process rotated log with PROG +,-PATTERN - (de)select line for
        logging E,ePATTERN - (de)select line for stderr

    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]] [-p PRI] [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
                -p PRI  Set swap device priority

    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]...

        Write all buffered blocks (in FILEs) to disk -d Avoid syncing
        metadata -f Sync filesystems underlying FILEs

    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)
                -K              Log to kernel printk buffer (use dmesg 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)

    tac tac [FILE]...

        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

    tar tar c|x|t [-zJjahmvokO] [-f TARFILE] [-C DIR] [-T FILE] [-X FILE]
        [LONGOPT]... [FILE]...

        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 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
                -T FILE File with names to include
                -X FILE File with glob patterns to exclude
                --exclude PATTERN       Glob pattern to exclude
                --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

    tc  tc OBJECT CMD [dev STRING]

        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|cbq|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]

    tcpsvd
        tcpsvd [-hEv] [-c N] [-C N[:MSG]] [-b N] [-u USER] [-l NAME] IP PORT
        PROG

        Create TCP socket, bind to IP:PORT and listen for incoming
        connections. Run PROG for each connection.

                IP PORT         IP:PORT to listen on
                PROG ARGS       Program to run
                -u USER[:GRP]   Change to user/group after bind
                -c N            Up to N connections simultaneously (default 30)
                -b N            Allow backlog of approximately N TCP SYNs (default 20)
                -C N[:MSG]      Allow only up to N connections from the same IP:
                                new connections from this IP address are closed
                                immediately, MSG is written to the peer before close
                -E              Don't set up environment
                -h              Look up peer's hostname
                -l NAME         Local hostname (else look up local hostname in DNS)
                -v              Verbose

        Environment if no -E: PROTO='TCP' TCPREMOTEADDR='ip:port'
        ('[ip]:port' for IPv6) TCPLOCALADDR='ip:port'
        TCPORIGDSTADDR='ip:port' of destination before firewall Useful for
        REDIRECTed-to-local connections: iptables -t nat -A PREROUTING -p
        tcp --dport 80 -j REDIRECT --to 8080
        TCPCONCURRENCY=num_of_connects_from_this_ip If -h:
        TCPLOCALHOST='hostname' (-l NAME is used if specified)
        TCPREMOTEHOST='hostname'

    tee tee [-ai] [FILE]...

        Copy stdin to each FILE, and also to stdout

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

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

        Connect to telnet server

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

    telnetd
        telnetd [OPTIONS]

        Handle incoming telnet connections

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

    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

    tftpd
        tftpd [-crl] [-u USER] [DIR]

        Transfer a file on tftp client's request

        tftpd is an inetd service, inetd.conf line: 69 dgram udp nowait root
        tftpd tftpd -l /files/to/serve Can be run from udpsvd:

                udpsvd -vE 0.0.0.0 69 tftpd /files/to/serve

                -r      Prohibit upload
                -c      Allow file creation via upload
                -u USER Access files as USER
                -l      Log to syslog (inetd mode requires this)

    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] SECS PROG ARGS

        Run PROG. Send SIG to it if it is not gone in SECS seconds. Default
        SIG: TERM.

    top top [-bmH] [-n COUNT] [-d SECONDS]

        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: show CPU usage, sort by pid/mem/cpu/time
                S: show memory
                R: reverse sort
                H: toggle threads, 1: toggle SMP
                Q,^C: exit
        Options:

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

    tr  tr [-cds] STRING1 [STRING2]

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

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

    traceroute
        traceroute [-46IFlnrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p
        PORT] [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE] [-z PAUSE_MSEC]
        HOST [BYTES]

        Trace the route to HOST

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

    traceroute6
        traceroute6 [-Inrv] [-f 1ST_TTL] [-m MAXTTL] [-q PROBES] [-p PORT]
        [-t TOS] [-w WAIT_SEC] [-s SRC_IP] [-i IFACE] [-z PAUSE_MSEC] HOST
        [BYTES]

        Trace the route to HOST

                -I      Use ICMP ECHO instead of UDP datagrams
                -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

    ts  ts [-is] [STRFTIME]

        Pipe stdin to stdout, add timestamp to each line

                -s      Time since start
                -i      Time since previous line

    tty tty [-s]

        Print file name of stdin's terminal

                -s      Print nothing, only return exit status

    ttysize
        ttysize [w] [h]

        Print dimensions of stdin tty, or 80x24

    tunctl
        tunctl [-f DEVICE] [-t NAME | -d NAME] [-u USER] [-g GRP] [-b]

        Create or delete TUN/TAP interfaces

                -f DEV  TUN device (default /dev/net/tun)
                -t NAME Create iface (default: tapN)
                -d NAME Delete iface
                -u USER Set iface owner
                -g GRP  Set iface group
                -b      Brief output

    ubiattach
        ubiattach -m MTD_NUM [-d UBI_NUM] [-O VID_HDR_OFF] UBI_CTRL_DEV

        Attach MTD device to UBI

                -m MTD_NUM      MTD device number to attach
                -d UBI_NUM      UBI device number to assign
                -O VID_HDR_OFF  VID header offset

    ubidetach
        ubidetach -d UBI_NUM UBI_CTRL_DEV

        Detach MTD device from UBI

                -d UBI_NUM      UBI device number

    ubimkvol
        ubimkvol -N NAME [-s SIZE | -m] UBI_DEVICE

        Create UBI volume

                -a ALIGNMENT    Volume alignment (default 1)
                -m              Set volume size to maximum available
                -n VOLID        Volume ID. If not specified,
                                assigned automatically
                -N NAME         Volume name
                -s SIZE         Size in bytes
                -t TYPE         Volume type (static|dynamic)

    ubirename
        ubirename UBI_DEVICE OLD_VOLNAME NEW_VOLNAME [OLD2 NEW2]...

        Rename UBI volumes on UBI_DEVICE

    ubirmvol
        ubirmvol -n VOLID | -N VOLNAME UBI_DEVICE

        Remove UBI volume

                -n VOLID        Volume ID
                -N VOLNAME      Volume name

    ubirsvol
        ubirsvol -n VOLID -s SIZE UBI_DEVICE

        Resize UBI volume

                -n VOLID        Volume ID
                -s SIZE         Size in bytes

    ubiupdatevol
        ubiupdatevol -t UBI_DEVICE | [-s SIZE] UBI_DEVICE IMG_FILE

        Update UBI volume

                -t      Truncate to zero size
                -s SIZE Size in bytes to resize to

    udhcpc
        udhcpc [-fbqvRB] [-a[MSEC]] [-t N] [-T SEC] [-A SEC|-n] [-i IFACE]
        [-s PROG] [-p PIDFILE] [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x
        OPT:VAL]... [-O OPT]...

                -i IFACE        Interface to use (default eth0)
                -s PROG         Run PROG at DHCP events (default /usr/share/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
                -v              Verbose
        Signals:

                USR1    Renew lease
                USR2    Release lease

    udhcpc6
        udhcpc6 [-fbqvR] [-t N] [-T SEC] [-A SEC|-n] [-i IFACE] [-s PROG]
        [-p PIDFILE] [-ldo] [-r IPv6] [-x OPT:VAL]... [-O OPT]...

                -i IFACE        Interface to use (default eth0)
                -p FILE         Create pidfile
                -s PROG         Run PROG at DHCP events (default /usr/share/udhcpc/default.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)
                -v              Verbose
        Signals:

                USR1    Renew lease
                USR2    Release lease

    udhcpd
        udhcpd [-fS] [-I ADDR] [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

    udpsvd
        udpsvd [-hEv] [-c N] [-u USER] [-l NAME] IP PORT PROG

        Create UDP socket, bind to IP:PORT and wait for incoming packets.
        Run PROG for each packet, redirecting all further packets with same
        peer ip:port to it.

                IP PORT         IP:PORT to listen on
                PROG ARGS       Program to run
                -u USER[:GRP]   Change to user/group after bind
                -c N            Up to N connections simultaneously (default 30)
                -E              Don't set up environment
                -h              Look up peer's hostname
                -l NAME         Local hostname (else look up local hostname in DNS)
                -v              Verbose

        Environment if no -E: PROTO='UDP' UDPREMOTEADDR='ip:port'
        ('[ip]:port' for IPv6) UDPLOCALADDR='ip:port' If -h:
        UDPLOCALHOST='hostname' (-l NAME is used if specified)
        UDPREMOTEHOST='hostname'

    uevent
        uevent [PROG ARGS]

        uevent runs PROG for every netlink notification. PROG's environment
        contains data passed from the kernel. Typical usage (daemon for
        dynamic device node creation): # uevent mdev & mdev -s

    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

    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 [-lnojpq] 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
                -x FILE Exclude FILEs
                -d DIR  Extract into DIR

    uptime
        uptime

        Display the time since the last boot

    users
        users

        Print the users currently logged on

    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

    vi  vi [-c CMD] [-R] [-H] [FILE]...

        Edit FILE

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

    vlock
        vlock [-a]

        Lock a virtual terminal. A password is required to unlock.

                -a      Lock all VTs

    volname
        volname [DEVICE]

        Show CD volume name of the DEVICE (default /dev/cdrom)

    w   w

        Show who is logged on

    wall
        wall [FILE]

        Write content of FILE or stdin to all logged-in users

    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

    wc  wc [-cmlwL] [FILE]...

        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
        wget [-cqS] [--spider] [-O FILE] [-o LOGFILE] [--header 'HEADER:
        VALUE'] [-Y on/off] [--no-check-certificate] [-P DIR] [-U AGENT] [-T
        SEC] URL...

        Retrieve files via HTTP or FTP

                --spider        Only check URL existence: $? is 0 if exists
                --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 COMMAND...

        Locate COMMAND

    who who [-aH]

        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

    whois
        whois [-i] [-h SERVER] [-p PORT] NAME...

        Query WHOIS info about NAME

                -i      Show redirect results too
                -h,-p   Server to query

    xargs
        xargs [OPTIONS] [PROG ARGS]

        Run PROG on every item given by stdin

                -0      Input is separated by NULs
                -a FILE Read from FILE instead of stdin
                -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

    xxd xxd [-pri] [-g N] [-c N] [-n LEN] [-s OFS] [-o OFS] [FILE]

        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)

    xz  xz -d [-cfk] [FILE]...

        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

    yes yes [STRING]

        Repeatedly print a line with STRING, or 'y'

    zcat
        zcat [FILE]...

        Decompress to stdout

    zcip
        zcip [OPTIONS] IFACE SCRIPT

        Manage a ZeroConf IPv4 link-local address

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

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

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

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

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

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

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

MAINTAINER
    Denis Vlasenko <vda.linux@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@tiscali.it>

        run-parts

    Erik Andersen <andersen@codepoet.org>

        Tons of new stuff, major rewrite of most of the
        core apps, tons of new apps as noted in header files.
        Lots of tedious effort writing these boring docs that
        nobody is going to actually read.

    Laurence Anderson <l.d.anderson@warwick.ac.uk>

        rpm2cpio, unzip, get_header_cpio, read_gz interface, rpm

    Jeff Angielski <jeff@theptrgroup.com>

        ftpput, ftpget

    Edward Betts <edward@debian.org>

        expr, hostid, logname, whoami

    John Beppu <beppu@codepoet.org>

        du, nslookup, sort

    Brian Candler <B.Candler@pobox.com>

        tiny-ls(ls)

    Randolph Chung <tausq@debian.org>

        fbset, ping, hostname

    Dave Cinege <dcinege@psychosis.com>

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

    Jordan Crouse <jordan@cosmicpenguin.net>

        ipcalc

    Magnus Damm <damm@opensource.se>

        tftp client insmod powerpc support

    Larry Doolittle <ldoolitt@recycle.lbl.gov>

        pristine source directory compilation, lots of patches and fixes.

    Glenn Engel <glenne@engel.org>

        httpd

    Gennady Feldman <gfeldman@gena01.com>

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

    Karl M. Hegbloom <karlheg@debian.org>

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

    Daniel Jacobowitz <dan@debian.org>

        mktemp.c

    Matt Kraai <kraai@alumni.cmu.edu>

        documentation, bugfixes, test suite

    Stephan Linz <linz@li-pro.net>

        ipcalc, Red Hat equivalence

    John Lombardo <john@deltanet.com>

        tr

    Glenn McGrath <bug1@iinet.net.au>

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

    Manuel Novoa III <mjn3@codepoet.org>

        cat, head, mkfifo, mknod, rmdir, sleep, tee, tty, uniq, usleep, wc, yes,
        mesg, vconfig, make_directory, parse_mode, dirname, mode_string,
        get_last_path_component, simplify_path, and a number trivial libbb routines

        also bug fixes, partial rewrites, and size optimizations in
        ash, basename, cal, cmp, cp, df, du, echo, env, ln, logname, md5sum, mkdir,
        mv, realpath, rm, sort, tail, touch, uname, watch, arith, human_readable,
        interface, dutmp, ifconfig, route

    Vladimir Oleynik <dzo@simtreas.ru>

        cmdedit; xargs(current), httpd(current);
        ports: ash, crond, fdisk, inetd, stty, traceroute, top;
        locale, various fixes
        and irreconcilable critic of everything not perfect.

    Bruce Perens <bruce@pixar.com>

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

    Tim Riker <Tim@Rikers.org>

        bug fixes, member of fan club

    Kent Robotti <robotti@metconnect.com>

        reset, tons and tons of bug reports and patches.

    Chip Rosenthal <chip@unicom.com>, <crosenth@covad.com>

        wget - Contributed by permission of Covad Communications

    Pavel Roskin <proski@gnu.org>

        Lots of bugs fixes and patches.

    Gyepi Sam <gyepi@praxis-sw.com>

        Remote logging feature for syslogd

    Linus Torvalds <torvalds@transmeta.com>

        mkswap, fsck.minix, mkfs.minix

    Mark Whitley <markw@codepoet.org>

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

    Charles P. Wright <cpwright@villagenet.com>

        gzip, mini-netcat(nc)

    Enrique Zanardi <ezanardi@ull.es>

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

    Tito Ragusa <farmatito@tiscali.it>

        devfsd and size optimizations in strings, openvt and deallocvt.

    Paul Fox <pgf@foxharp.boston.ma.us>

        vi editing mode for ash, various other patches/fixes

    Roberto A. Foglietta <me@roberto.foglietta.name>

        port: dnsd

    Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

        misc

    Mike Frysinger <vapier@gentoo.org>

        initial e2fsprogs, printenv, setarch, sum, misc

    Jie Zhang <jie.zhang@analog.com>

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

