# vi: set sw=4 ts=4: =head1 NAME BusyBox - The Swiss Army Knife of Embedded Linux =head1 SYNTAX BusyBox [arguments...] # or [arguments...] # if symlinked =head1 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 fileutils, shellutils, findutils, textutils, grep, gzip, tar, etc. BusyBox provides a fairly complete POSIX environment for any small or emdedded system. The utilities in BusyBox generally have fewer options then 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 a kernel, a shell (such as ash), and an editor (such as elvis-tiny or ae). =head1 USAGE When you create a link to BusyBox for the function you wish to use, when BusyBox is called using that link it will behave as if the command itself has been invoked. For example, entering ln -s ./BusyBox ls ./ls will cause BusyBox to behave as 'ls' (if the 'ls' command has been compiled into BusyBox). You can also invoke BusyBox by issuing the command as an argument on the command line. For example, entering ./BusyBox ls will also cause BusyBox to behave as 'ls'. =head1 COMMON OPTIONS Most BusyBox commands support the B<--help> option to provide a terse runtime description of their behavior. =head1 COMMANDS Currently defined functions include: basename, cat, chgrp, chmod, chown, chroot, clear, chvt, cp, date, dd, df, dirname, dmesg, du, dutmp, echo, false, fbset, fdflush, find, free, freeramdisk, deallocvt, fsck.minix, grep, gunzip, gzip, halt, head, hostid, hostname, init, kill, killall, length, ln, loadacm, loadfont, loadkmap, logger, logname, ls, lsmod, makedevs, math, mkdir, mkfifo, mkfs.minix, mknod, mkswap, mktemp, mnc, more, mount, mt, mv, nslookup, ping, poweroff, printf, ps, pwd, reboot, rm, rmdir, rmmod, sed, sh, sfdisk, sleep, sort, sync, syslogd, swapon, swapoff, tail, tar, test, tee, touch, tr, true, tty, umount, uname, uniq, update, uptime, usleep, wc, whoami, yes, zcat, [ =over 4 =item basename Usage: basename [file ...] Strips directory path and suffixes from FILE(s). Example: $ basename /usr/local/bin/foo foo $ basename /usr/local/bin/ bin ------------------------------- =item cat Usage: cat [FILE ...] Concatenates FILE(s) and prints them to the standard output. Example: $ cat /proc/uptime 110716.72 17.67 ------------------------------- =item chgrp Usage: chgrp [OPTION]... GROUP FILE... Change the group membership of each FILE to GROUP. Options: -R change files and directories recursively Example: $ ls -l /tmp/foo -r--r--r-- 1 andersen andersen 0 Apr 12 18:25 /tmp/foo $ chgrp root /tmp/foo $ ls -l /tmp/foo -r--r--r-- 1 andersen root 0 Apr 12 18:25 /tmp/foo ------------------------------- =item chmod Usage: chmod [B<-R>] MODE[,MODE]... FILE... Changes file access permissions for the specified FILE(s) (or directories). Each MODE is defined by combining the letters for WHO has access to the file, an OPERATOR for selecting how the permissions should be changed, and a PERISSION for FILE(s) (or directories). WHO may be chosen from u User who owns the file g Users in the file's Group o Other users not in the file's group a All users OPERATOR may be chosen from + Add a permission - Remove a permission = Assign a permission PERMISSION may be chosen from r Read w Write x Execute (or access for directories) s Set user (or group) ID bit t Stickey bit (for directories prevents removing files by non-owners) Alternately, permissions can be set numerically where the first three numbers are calculated by adding the octal values, such as 4 Read 2 Write 1 Execute An optional fourth digit can also be used to specify 4 Set user ID 2 Set group ID 1 Stickey bit Options: -R Change files and directories recursively. Example: $ ls -l /tmp/foo -rw-rw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo $ chmod u+x /tmp/foo $ ls -l /tmp/foo -rwxrw-r-- 1 root root 0 Apr 12 18:25 /tmp/foo* $ chmod 444 /tmp/foo $ ls -l /tmp/foo -r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo ------------------------------- =item chown Usage: chown [OPTION]... OWNER[<.|:>[GROUP] FILE... Changes the owner and/or group of each FILE to OWNER and/or GROUP. Options: -R Changes files and directories recursively Example: $ ls -l /tmp/foo -r--r--r-- 1 andersen andersen 0 Apr 12 18:25 /tmp/foo $ chown root /tmp/foo $ ls -l /tmp/foo -r--r--r-- 1 root andersen 0 Apr 12 18:25 /tmp/foo $ chown root.root /tmp/foo ls -l /tmp/foo -r--r--r-- 1 root root 0 Apr 12 18:25 /tmp/foo ------------------------------- =item chroot Usage: chroot NEWROOT [COMMAND...] Run COMMAND with root directory set to NEWROOT. Example: $ ls -l /bin/ls lrwxrwxrwx 1 root root 12 Apr 13 00:46 /bin/ls -> /BusyBox $ mount /dev/hdc1 /mnt -t minix $ chroot /mnt $ ls -l /bin/ls -rwxr-xr-x 1 root root 40816 Feb 5 07:45 /bin/ls* ------------------------------- =item clear Clears the screen. ------------------------------- =item chvt Usage: chvt N Changes the foreground virtual terminal to /dev/ttyN ------------------------------- =item cp Usage: cp [OPTION]... SOURCE DEST or: cp [OPTION]... SOURCE... DIRECTORY Copies SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY. -a Same as -dpR -d Preserves links -p Preserves file attributes if possable -R Copies directories recursively ------------------------------- =item date Usage: date [OPTION]... [+FORMAT] or: date [OPTION] [MMDDhhmm[[CC]YY][.ss]] Displays the current time in the given FORMAT, or sets the system date. Options: -R Outputs RFC-822 compliant date string -s Sets time described by STRING -u Prints or sets Coordinated Universal Time Example: $ date Wed Apr 12 18:52:41 MDT 2000 ------------------------------- =item dd Usage: dd [if=name] [of=name] [bs=n] [count=n] [skip=n] [seek=n] Copy a file, converting and formatting according to options if=FILE read from FILE instead of stdin of=FILE write to FILE instead of stdout bs=n read and write n bytes at a time count=n copy only n input blocks skip=n skip n input blocks seek=n skip n output blocks Numbers may be suffixed by w (x2), k (x1024), b (x512), or M (x1024^2) Example: $ dd if=/dev/zero of=/dev/ram1 bs=1M count=4 4+0 records in 4+0 records out ------------------------------- =item df Usage: df [filesystem ...] Prints the filesystem space used and space available. Example: $ df Filesystem 1k-blocks Used Available Use% Mounted on /dev/sda3 8690864 8553540 137324 98% / /dev/sda1 64216 36364 27852 57% /boot $ df /dev/sda3 Filesystem 1k-blocks Used Available Use% Mounted on /dev/sda3 8690864 8553540 137324 98% / ------------------------------- =item dirname Usage: dirname NAME Strip non-directory suffix from file name Example: $ dirname /tmp/foo /tmp $ dirname /tmp/foo/ /tmp ------------------------------- =item dmesg Usage: dmesg [B<-c>] [B<-n> level] [B<-s> bufsize] Print or controls the kernel ring buffer. ------------------------------- =item du Usage: du [OPTION]... [FILE]... Summarize disk space used for each FILE and/or directory. Disk space is printed in units of 1k (i.e. 1024 bytes). Options: -l count sizes many times if hard linked -s display only a total for each argument Example: $ ./BusyBox du 16 ./CVS 12 ./kernel-patches/CVS 80 ./kernel-patches 12 ./tests/CVS 36 ./tests 12 ./scripts/CVS 16 ./scripts 12 ./docs/CVS 104 ./docs 2417 . ------------------------------- =item dutmp Usage: dutmp [FILE] Dump utmp file format (pipe delimited) from FILE or stdin to stdout. Example: $ dutmp /var/run/utmp 8|7||si|||0|0|0|955637625|760097|0 2|0|~|~~|reboot||0|0|0|955637625|782235|0 1|20020|~|~~|runlevel||0|0|0|955637625|800089|0 8|125||l4|||0|0|0|955637629|998367|0 6|245|tty1|1|LOGIN||0|0|0|955637630|998974|0 6|246|tty2|2|LOGIN||0|0|0|955637630|999498|0 7|336|pts/0|vt00andersen|andersen|:0.0|0|0|0|955637763|0|0 ------------------------------- =item echo Usage: echo [-neE] [ARG ...] Prints the specified ARGs to stdout Options: -n suppress trailing newline -e interpret backslash-escaped characters (i.e. \t=tab etc) -E disable interpretation of backslash-escaped characters Example: $ echo "Erik is cool" Erik is cool $ echo -e "Erik\nis\ncool" Erik is cool $ echo "Erik\nis\ncool" Erik\nis\ncool ------------------------------- =item false Returns an exit code of FALSE (1) Example: $ false $ echo $? 1 ------------------------------- =item fbset Usage: fbset [options] [mode] Show and modify frame buffer device settings Options: -h -fb -db -a -i -g -t -accel -hsync -vsync -laced -double Example: $ fbset mode "1024x768-76" # D: 78.653 MHz, H: 59.949 kHz, V: 75.694 Hz geometry 1024 768 1024 768 16 timings 12714 128 32 16 4 128 4 accel false rgba 5/11,6/5,5/0,0/0 endmode ------------------------------- =item fdflush Usage: fdflush device Force floppy disk drive to detect disk change ------------------------------- =item find Usage: find [PATH...] [EXPRESSION] Search for files in a directory hierarchy. The default PATH is the current directory; default EXPRESSION is '-print' EXPRESSION may consist of: -follow Dereference symbolic links. -name PATTERN File name (leading directories removed) matches PATTERN. -print print the full file name followed by a newline to stdout. Example: $ find / -name /etc/passwd /etc/passwd ------------------------------- =item free Usage: free Displays the amount of free and used memory in the system. Example: $ free total used free shared buffers Mem: 257628 248724 8904 59644 93124 Swap: 128516 8404 120112 Total: 386144 257128 129016 ------------------------------- =item freeramdisk Usage: freeramdisk DEVICE Free all memory used by the specified ramdisk. Example: $ freeramdisk /dev/ram2 ------------------------------- =item deallocvt Usage: deallocvt N Deallocates unused virtual terminal /dev/ttyN ------------------------------- =item fsck.minix Usage: fsck.minix [B<-larvsmf>] /dev/name Performs a consistency check for MINIX filesystems. OPTIONS: -l Lists all filenames -r Perform interactive repairs -a Perform automatic repairs -v verbose -s Outputs super-block information -m Activates MINIX-like "mode not cleared" warnings -f Force file system check. ------------------------------- =item grep Usage: grep [OPTIONS]... PATTERN [FILE]... Search for PATTERN in each FILE or standard input. OPTIONS: -h suppress the prefixing filename on output -i ignore case distinctions -n print line number with output lines -q be quiet. Returns 0 if result was found, 1 otherwise -v select non-matching lines This version of grep matches full regular expresions. Example: $ grep root /etc/passwd root:x:0:0:root:/root:/bin/bash $ grep ^[rR]oo. /etc/passwd root:x:0:0:root:/root:/bin/bash ------------------------------- =item gunzip Usage: gunzip [OPTION]... FILE Uncompress FILE (or standard input if FILE is '-'). Options: -c Write output to standard output -t Test compressed file integrity Example: $ ls -la /tmp/BusyBox* -rw-rw-r-- 1 andersen andersen 557009 Apr 11 10:55 /tmp/BusyBox-0.43.tar.gz $ gunzip /tmp/BusyBox-0.43.tar.gz $ ls -la /tmp/BusyBox* -rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/BusyBox-0.43.tar ------------------------------- =item gzip Usage: gzip [OPTION]... FILE Compress FILE with maximum compression. When FILE is '-', reads standard input. Implies B<-c>. Options: -c Write output to standard output instead of FILE.gz Example: $ ls -la /tmp/BusyBox* -rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/BusyBox-0.43.tar $ gzip /tmp/BusyBox-0.43.tar $ ls -la /tmp/BusyBox* -rw-rw-r-- 1 andersen andersen 554058 Apr 14 17:49 /tmp/BusyBox-0.43.tar.gz ------------------------------- =item halt Usage: halt This comand halts the system. ------------------------------- =item head Usage: head [OPTION] [FILE]... Print first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Options: -n NUM Print first NUM lines instead of first 10 Example: $ head -n 2 /etc/passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/bin/sh ------------------------------- =item hostid Usage: hostid Prints out a unique 32-bit identifier for the current machine. The 32-bit identifier is intended to be unique among all UNIX systems in existence. ------------------------------- =item hostname Usage: hostname [OPTION] {hostname | B<-F> file} Get or set the hostname or DNS domain name. If a hostname is given (or a file with the B<-F> parameter), the host name will be set. Options: -s Short -i Addresses for the hostname -d DNS domain name -F FILE Use the contents of FILE to specify the hostname Example: $ hostname slag ------------------------------- =item init Usage: init Init is the parent of all processes. This version of init is designed to be run only by the kernel. BusyBox init doesn't support multiple runlevels. The runlevels field of the /etc/inittab file is completely ignored by BusyBox init. If you want runlevels, use sysvinit. BusyBox init works just fine without an inittab. If no inittab is found, it has the following default behavior: ::sysinit:/etc/init.d/rcS ::askfirst:/bin/sh if it detects that /dev/console is _not_ a serial console, it will also run: tty2::askfirst:/bin/sh If you choose to use an /etc/inittab file, the inittab entry format is as follows: ::: : WARNING: This field has a non-traditional meaning for BusyBox init! The id field is used by BusyBox init to specify the controlling tty for the specified process to run on. The contents of this field are appended to "/dev/" and used as-is. There is no need for this field to be unique, although if it isn't you may have strange results. If this field is left blank, it is completely ignored. Also note that if BusyBox detects that a serial console is in use, then all entries containing non-empty id fields will _not_ be run. BusyBox init does nothing with utmp. We don't need no stinkin' utmp. : The runlevels field is completely ignored. : Valid actions include: sysinit, respawn, askfirst, wait, once, and ctrlaltdel. askfirst acts just like respawn, but before running the specified process it displays the line "Please press Enter to activate this console." and then waits for the user to press enter before starting the specified process. Unrecognised actions (like initdefault) will cause init to emit an error message, and then go along with its business. : Specifies the process to be executed and it's command line. Example /etc/inittab file: # This is run first except when booting in single-user mode. # ::sysinit:/etc/init.d/rcS # /bin/sh invocations on selected ttys # # Start an "askfirst" shell on the console (whatever that may be) ::askfirst:/bin/sh # Start an "askfirst" shell on /dev/tty2 tty2::askfirst:/bin/sh # /sbin/getty invocations for selected ttys # tty4::respawn:/sbin/getty 38400 tty4 tty5::respawn:/sbin/getty 38400 tty5 # Example of how to put a getty on a serial line (for a terminal) # #ttyS0::respawn:/sbin/getty -L ttyS0 9600 vt100 #ttyS1::respawn:/sbin/getty -L ttyS1 9600 vt100 # # Example how to put a getty on a modem line. #ttyS2::respawn:/sbin/getty -x0 -s 57600 ttyS2 # Stuff to do before rebooting ::ctrlaltdel:/bin/umount -a -r > /dev/null 2>&1 ::ctrlaltdel:/sbin/swapoff -a > /dev/null 2>&1 ------------------------------- =item kill Usage: kill [B<-signal>] process-id [process-id ...] Send a signal (default is SIGTERM) to the specified process(es). Options: -l List all signal names and numbers. Example: $ ps | grep apache 252 root root S [apache] 263 www-data www-data S [apache] 264 www-data www-data S [apache] 265 www-data www-data S [apache] 266 www-data www-data S [apache] 267 www-data www-data S [apache] $ kill 252 ------------------------------- =item killall Usage: killall [B<-signal>] process-name [process-name ...] Send a signal (default is SIGTERM) to the specified process(es). Options: -l List all signal names and numbers. Example: $ killall apache ------------------------------- =item length Usage: length string Prints out the length of the specified string. Example: $ length "Hello" 5 ------------------------------- =item ln Usage: ln [OPTION] TARGET... LINK_NAME|DIRECTORY Create a link named LINK_NAME or DIRECTORY to the specified TARGET Options: -s make symbolic links instead of hard links -f remove existing destination files Example: $ ln -s BusyBox /tmp/ls [andersen@debian BusyBox]$ ls -l /tmp/ls lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox* ------------------------------- =item loadacm Usage: loadacm Loads an acm from standard input. Example: $ loadacm < /etc/i18n/acmname ------------------------------- =item loadfont Usage: loadfont Loads a console font from standard input. Example: $ loadfont < /etc/i18n/fontname ------------------------------- =item loadkmap Usage: loadkmap Loads a binary keyboard translation table from standard input. Example: $ loadkmap < /etc/i18n/lang-keymap ------------------------------- =item logger Usage: logger [OPTION]... [MESSAGE] Write MESSAGE to the system log. If MESSAGE is '-', log stdin. Options: -s Log to stderr as well as the system log. -t Log using the specified tag (defaults to user name). -p Enter the message with the specified priority. This may be numerical or a ``facility.level'' pair. Example: $ logger "hello" ------------------------------- =item logname Usage: logname Print the name of the current user. Example: $ logname root ------------------------------- =item ls Usage: ls [B<-1acdelnpuxACF>] [filenames...] Options: -a do not hide entries starting with . -c with -l: show ctime (the time of last modification of file status information) -d list directory entries instead of contents -e list both full date and full time -l use a long listing format -n list numeric UIDs and GIDs instead of names -p append indicator (one of /=@|) to entries -u with -l: show access time (the time of last access of the file) -x list entries by lines instead of by columns -A do not list implied . and .. -C list entries by columns -F append indicator (one of */=@|) to entries ------------------------------- =item lsmod Usage: lsmod Shows a list of all currently loaded kernel modules. ------------------------------- =item makedevs Usage: makedevs NAME TYPE MAJOR MINOR FIRST LAST [s] Creates a range of block or character special files TYPEs include: b: Make a block (buffered) device. c or u: Make a character (un-buffered) device. p: Make a named pipe. MAJOR and MINOR are ignored for named pipes. FIRST specifies the number appended to NAME to create the first device. LAST specifies the number of the last item that should be created. If 's' is the last argument, the base device is created as well. Example: $ makedevs /dev/ttyS c 4 66 2 63 [creates ttyS2-ttyS63] $ makedevs /dev/hda b 3 0 0 8 s [creates hda,hda1-hda8] ------------------------------- =item math Usage: math expression ... This is a Tiny RPN calculator that understands the following operations: +, -, /, *, and, or, not, eor. Example: $ math 2 2 add 4 $ math 8 8 \* 2 2 + / 16 $ math 0 1 and 0 $ math 0 1 or 1 ------------------------------- =item mkdir Usage: mkdir [OPTION] DIRECTORY... Create the DIRECTORY(ies), if they do not already exist Options: -m set permission mode (as in chmod), not rwxrwxrwx - umask -p no error if dir exists, make parent directories as needed Example: $ mkdir /tmp/foo $ mkdir /tmp/foo /tmp/foo: File exists $ mkdir /tmp/foo/bar/baz /tmp/foo/bar/baz: No such file or directory $ mkdir -p /tmp/foo/bar/baz ------------------------------- =item mkfifo Usage: mkfifo [OPTIONS] name Creates a named pipe (identical to 'mknod name p') Options: -m create the pipe using the specified mode (default a=rw) ------------------------------- =item mkfs.minix Usage: mkfs.minix [B<-c> | B<-l> filename] [B<-nXX>] [B<-iXX>] /dev/name [blocks] Make a MINIX filesystem. OPTIONS: -c Check the device for bad blocks -n [14|30] Specify the maximum length of filenames -i Specify the number of inodes for the filesystem -l FILENAME Read the bad blocks list from FILENAME -v Make a Minix version 2 filesystem ------------------------------- =item mknod Usage: mknod [OPTIONS] NAME TYPE MAJOR MINOR Create a special file (block, character, or pipe). Options: -m create the special file using the specified mode (default a=rw) TYPEs include: b: Make a block (buffered) device. c or u: Make a character (un-buffered) device. p: Make a named pipe. MAJOR and MINOR are ignored for named pipes. Example: $ mknod /dev/fd0 b 2 0 $ mknod -m 644 /tmp/pipe p ------------------------------- =item mkswap Usage: mkswap [B<-c>] [B<-v0>|B<-v1>] device [block-count] Prepare a disk partition to be used as a swap partition. Options: -c Check for read-ability. -v0 Make version 0 swap [max 128 Megs]. -v1 Make version 1 swap [big!] (default for kernels > 2.1.117). block-count Number of block to use (default is entire partition). ------------------------------- =item mktemp Usage: mktemp [-q] TEMPLATE Creates a temporary file with its name based on TEMPLATE. TEMPLATE is any name with six `Xs' (i.e. /tmp/temp.XXXXXX). Example: $ mktemp /tmp/temp.XXXXXX /tmp/temp.mWiLjM $ ls -la /tmp/temp.mWiLjM -rw------- 1 andersen andersen 0 Apr 25 17:10 /tmp/temp.mWiLjM ------------------------------- =item mnc Usage: mnc [IP] [port] mini-netcat opens a pipe to IP:port Example: $ mnc foobar.somedomain.com 25 220 foobar ESMTP Exim 3.12 #1 Sat, 15 Apr 2000 00:03:02 -0600 help 214-Commands supported: 214- HELO EHLO MAIL RCPT DATA AUTH 214 NOOP QUIT RSET HELP quit 221 foobar closing connection ------------------------------- =item more Usage: more [file ...] More is a filter for paging through text one screenful at a time. Example: $ dmesg | more ------------------------------- =item mount Usage: mount [flags] mount [flags] device directory [B<-o> options,more-options] Flags: -a: Mount all file systems in fstab. -o option: One of many filesystem options, listed below. -r: Mount the filesystem read-only. -t filesystem-type: Specify the filesystem type. -w: Mount for reading and writing (default). Options for use with the "B<-o>" flag: async / sync: Writes are asynchronous / synchronous. dev / nodev: Allow use of special device files / disallow them. exec / noexec: Allow use of executable files / disallow them. loop: Mounts a file via loop device. suid / nosuid: Allow set-user-id-root programs / disallow them. remount: Re-mount a currently-mounted filesystem, changing its flags. ro / rw: Mount for read-only / read-write. There are EVEN MORE flags that are specific to each filesystem. You'll have to see the written documentation for those. Example: $ mount /dev/hda3 on / type minix (rw) proc on /proc type proc (rw) devpts on /dev/pts type devpts (rw) $ mount /dev/fd0 /mnt -t msdos -o ro $ mount /tmp/diskimage /opt -t ext2 -o loop ------------------------------- =item mt Usage: mt [B<-f> device] opcode value Control magnetic tape drive operation ------------------------------- =item mv Usage: mv SOURCE DEST or: mv SOURCE... DIRECTORY Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY. Example: $ mv /tmp/foo /bin/bar ------------------------------- =item nslookup Usage: nslookup [HOST] Queries the nameserver for the IP address of the given HOST Example: $ nslookup localhost Server: default Address: default Name: debian Address: 127.0.0.1 ------------------------------- =item ping Usage: ping [OPTION]... host Send ICMP ECHO_REQUEST packets to network hosts. Options: -c COUNT Send only COUNT pings. -q Quiet mode, only displays output at start and when finished. Example: $ ping localhost PING slag (127.0.0.1): 56 data bytes 64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=20.1 ms --- debian ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max = 20.1/20.1/20.1 ms ------------------------------- =item poweroff Shuts down the system, and requests that the kernel turn off power upon halting. ------------------------------- =item printf Usage: printf format [argument...] Formats and prints the given data in a manner similar to the C printf command. Example: $ printf "Val=%d\n" 5 Val=5 ------------------------------- =item ps Usage: ps Report process status This version of ps accepts no options. Example: $ ps PID Uid Gid State Command 1 root root S init 2 root root S [kflushd] 3 root root S [kupdate] 4 root root S [kpiod] 5 root root S [kswapd] 742 andersen andersen S [bash] 743 andersen andersen S -bash 745 root root S [getty] 2990 andersen andersen R ps ------------------------------- =item pwd Prints the full filename of the current working directory. Example: $ pwd /root ------------------------------- =item reboot Instructs the kernel to reboot the system. ------------------------------- =item rm Usage: rm [OPTION]... FILE... Remove (unlink) the FILE(s). Options: -f remove existing destinations, never prompt -r or -R remove the contents of directories recursively Example: $ rm -rf /tmp/foo ------------------------------- =item rmdir Usage: rmdir [OPTION]... DIRECTORY... Remove the DIRECTORY(ies), if they are empty. Example: # rmdir /tmp/foo ------------------------------- =item rmmod Usage: rmmod [OPTION]... [MODULE]... Unloads the specified kernel modules from the kernel. Options: -a Try to remove all unused kernel modules. Example: $ rmmod tulip ------------------------------- =item sed Usage: sed [B<-n>] B<-e> script [file...] Allowed sed scripts come in the following form: 'ADDR [!] COMMAND' where address ADDR can be: NUMBER Match specified line number $ Match last line /REGEXP/ Match specified regexp (! inverts the meaning of the match) and COMMAND can be: s/regexp/replacement/[igp] which attempt to match regexp against the pattern space and if successful replaces the matched portion with replacement. aTEXT which appends TEXT after the pattern space Options: -e add the script to the commands to be executed -n suppress automatic printing of pattern space This version of sed matches full regular expresions. Example: $ echo "foo" | sed -e 's/f[a-zA-Z]o/bar/g' bar ------------------------------- =item sh Usage: sh lash -- the BusyBox LAme SHell (command interpreter) This command does not yet have proper documentation. Use lash just as you would use any other shell. It properly handles pipes, redirects, job control, can be used as the shell for scripts (#!/bin/sh), and has a sufficient set of builtins to do what is needed. It does not (yet) support Bourne Shell syntax. If you need things like "if-then-else", "while", and such, use ash or bash. If you just need a very simple and extremely small shell, this will do the job. ------------------------------- =item sfdisk Usage: sfdisk [options] device ... device: something like /dev/hda or /dev/sda useful options: -s [or --show-size]: list size of a partition -c [or --id]: print or change partition Id -l [or --list]: list partitions of each device -d [or --dump]: idem, but in a format suitable for later input -i [or --increment]: number cylinders etc. from 1 instead of from 0 -uS, -uB, -uC, -uM: accept/report in units of sectors/blocks/cylinders/MB -T [or --list-types]:list the known partition types -D [or --DOS]: for DOS-compatibility: waste a little space -R [or --re-read]: make kernel reread partition table -N# : change only the partition with number # -n : do not actually write to disk -O file : save the sectors that will be overwritten to file -I file : restore these sectors again -v [or --version]: print version -? [or --help]: print this message dangerous options: -g [or --show-geometry]: print the kernel's idea of the geometry -x [or --show-extended]: also list extended partitions on output or expect descriptors for them on input -L [or --Linux]: do not complain about things irrelevant for Linux -q [or --quiet]: suppress warning messages You can override the detected geometry using: -C# [or --cylinders #]:set the number of cylinders to use -H# [or --heads #]: set the number of heads to use -S# [or --sectors #]: set the number of sectors to use You can disable all consistency checking with: -f [or --force]: do what I say, even if it is stupid ------------------------------- =item sleep Usage: sleep N Pause for N seconds. Example: $ sleep 2 [2 second delay results] ------------------------------- =item sort Usage: sort [B<-n>] [B<-r>] [FILE]... Sorts lines of text in the specified files Example: $ echo -e "e\nf\nb\nd\nc\na" | sort a b c d e f ------------------------------- =item sync Usage: sync Write all buffered filesystem blocks to disk. ------------------------------- =item syslogd Usage: syslogd [OPTION]... Linux system and kernel (provides klogd) logging utility. Note that this version of syslogd/klogd ignores /etc/syslog.conf. Options: -m Change the mark timestamp interval. default=20min. 0=off -n Do not fork into the background (for when run by init) -K Do not start up the klogd process (by default syslogd spawns klogd). -O Specify an alternate log file. default=/var/log/messages ------------------------------- =item swapon Usage: swapon [OPTION] [device] Start swapping virtual memory pages on the given device. Options: -a Start swapping on all swap devices ------------------------------- =item swapoff Usage: swapoff [OPTION] [device] Stop swapping virtual memory pages on the given device. Options: -a Stop swapping on all swap devices ------------------------------- =item tail Usage: tail [OPTION] [FILE]... Print last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input. Options: -n NUM Print last NUM lines instead of first 10 -f Output data as the file grows. This version of 'tail -f' supports only one file at a time. Example: $ tail -n 1 /etc/resolv.conf nameserver 10.0.0.1 ------------------------------- =item tar Usage: tar -[cxtvO] [B<--exclude> File] [B<-f> tarFile] [FILE] ... Create, extract, or list files from a tar file. Note that this version of tar treats hard links as separate files. Main operation mode: c create x extract t list File selection: f name of tarfile or "-" for stdin O extract to stdout --exclude file to exclude Informative output: v verbosely list files processed Example: $ zcat /tmp/tarball.tar.gz | tar -xf - $ tar -cf /tmp/tarball.tar /usr/local ------------------------------- =item test, [ Usage: test EXPRESSION or [ EXPRESSION ] Checks file types and compares values returning an exit code determined by the value of EXPRESSION. Example: $ test 1 -eq 2 $ echo $? 1 $ test 1 -eq 1 $ echo $? 0 $ [ -d /etc ] $ echo $? 0 $ [ -d /junk ] $ echo $? 1 ------------------------------- =item tee Usage: tee [OPTION]... [FILE]... Copy standard input to each FILE, and also to standard output. Options: -a append to the given FILEs, do not overwrite Example: $ echo "Hello" | tee /tmp/foo $ cat /tmp/foo Hello ------------------------------- =item touch Usage: touch [B<-c>] file [file ...] Update the last-modified date on (or create) the selected file[s]. Example: $ ls -l /tmp/foo /bin/ls: /tmp/foo: No such file or directory $ touch /tmp/foo $ ls -l /tmp/foo -rw-rw-r-- 1 andersen andersen 0 Apr 15 01:11 /tmp/foo ------------------------------- =item tr Usage: tr [B<-cdsu>] string1 [string2] Translate, squeeze, and/or delete characters from standard input, writing to standard output. Example: $ echo "gdkkn vnqkc" | tr [a-y] [b-z] hello world ------------------------------- =item true Returns an exit code of TRUE (0) Example: $ true $ echo $? 0 ------------------------------- =item tty Usage: tty Print the file name of the terminal connected to standard input. Options: -s print nothing, only return an exit status Example: $ tty /dev/tty2 ------------------------------- =item umount Usage: umount [flags] filesystem|directory Flags: -a: Unmount all file systems -r: Try to remount devices as read-only if mount is busy -f: Do not free loop device (if a loop device has been used) Example: $ umount /dev/hdc1 ------------------------------- =item uname Usage: uname [OPTION]... Print certain system information. With no OPTION, same as B<-s>. Options: -a print all information -m the machine (hardware) type -n print the machine's network node hostname -r print the operating system release -s print the operating system name -p print the host processor type -v print the operating system version Example: $ uname -a Linux debian 2.2.15pre13 #5 Tue Mar 14 16:03:50 MST 2000 i686 unknown ------------------------------- =item uniq Usage: uniq [OPTION]... [INPUT [OUTPUT]] Discard all but one of successive identical lines from INPUT (or standard input), writing to OUTPUT (or standard output). Example: $ echo -e "a\na\nb\nc\nc\na" | sort | uniq a b c ------------------------------- =item update Usage: update [options] Periodically flushes filesystem buffers. Options: -S force use of sync(2) instead of flushing -s SECS call sync this often (default 30) -f SECS flush some buffers this often (default 5) ------------------------------- =item uptime Usage: uptime Tells how long the system has been running since boot. Example: $ uptime 1:55pm up 2:30, load average: 0.09, 0.04, 0.00 ------------------------------- =item usleep Usage: usleep N Pauses for N microseconds. Example: $ usleep 1000000 [pauses for 1 second] ------------------------------- =item wc Usage: wc [OPTION]... [FILE]... Print line, word, and byte counts for each FILE, and a total line if more than one FILE is specified. With no FILE, read standard input. Options: -c print the byte counts -l print the newline counts -L print the length of the longest line -w print the word counts Example: $ wc /etc/passwd 31 46 1365 /etc/passwd ------------------------------- =item whoami Usage: whoami Prints the user name associated with the current effective user id. Example: $ whoami andersen ------------------------------- =item yes Usage: yes [OPTION]... [STRING]... Repeatedly outputs a line with all specified STRING(s), or `y'. ------------------------------- =item zcat This is essentially an alias for invoking "gunzip B<-c>", where it decompresses the file inquestion and send the output to stdout. ------------------------------- =back =head1 SEE ALSO textutils(1), shellutils(1), etc... =head1 MAINTAINER Erik Andersen =head1 AUTHORS The following people have contributed code to BusyBox whether they know it or not. Erik Andersen =for html
John Beppu =for html
Brian Candler =for html
Randolph Chung =for html
Dave Cinege =for html
Karl M. Hegbloom =for html
John Lombardo =for html
Bruce Perens =for html
Linus Torvalds =for html
Charles P. Wright =for html
Enrique Zanardi =for html
=cut # $Id: busybox.pod,v 1.23 2000/04/25 23:24:55 erik Exp $