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Currently defined functions include:
[, [[, addgroup, adduser, adjtimex, ar, arp, arping, ash, awk,
basename, bbconfig, bbsh, bunzip2, busybox, bzcat, cal, cat,
catv, chattr, chcon, chgrp, chmod, chown, chpasswd, chpst,
chroot, chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond,
crontab, cryptpw, cut, date, dc, dd, deallocvt, delgroup,
deluser, devfsd, df, dhcprelay, diff, dirname, dmesg, dnsd,
dos2unix, dpkg, dpkg_deb, du, dumpkmap, dumpleases, e2fsck, echo,
ed, eject, env, envdir, envuidgid, ether_wake, expand, expr,
fakeidentd, false, fbset, fdflush, fdformat, fdisk, find, fold,
free, freeramdisk, fsck, fsck_minix, ftpget, ftpput, fuser,
getenforce, getopt, getsebool, getty, grep, gunzip, gzip, halt,
hdparm, head, hexdump, hostid, hostname, httpd, hwclock, id,
ifconfig, ifdown, ifup, inetd, init, insmod, install, ip, ipaddr,
ipcalc, ipcrm, ipcs, iplink, iproute, iprule, iptunnel, kill,
killall, killall5, klogd, lash, last, length, less, ln,
load_policy, loadfont, loadkmap, logger, login, logname, logread,
losetup, ls, lsattr, lsmod, lzmacat, makedevs, matchpathcon,
md5sum, mdev, mesg, microcom, mkdir, mke2fs, mkfifo, mkfs_minix,
mknod, mkswap, mktemp, modprobe, more, mount, mountpoint, mt, mv,
nameif, nc, netstat, nice, nmeter, nohup, nslookup, od, openvt,
passwd, patch, pgrep, pidof, ping, ping6, pivot_root, pkill,
poweroff, printenv, printf, ps, pscan, pwd, raidautorun, rdate,
readahead, readlink, readprofile, realpath, reboot, renice,
reset, resize, restorecon, rm, rmdir, rmmod, route, rpm,
rpm2cpio, run_parts, runcon, runlevel, runsv, runsvdir, rx, sed,
selinuxenabled, seq, setarch, setconsole, setenforce, setfiles,
setkeycodes, setlogcons, setsid, setuidgid, sha1sum, slattach,
sleep, softlimit, sort, split, start_stop_daemon, stat, strings,
stty, su, sulogin, sum, sv, svlogd, swapoff, swapon, switch_root,
sync, sysctl, syslogd, tail, tar, taskset, tcpsvd, tee, telnet,
telnetd, test, tftp, time, top, touch, tr, traceroute, true, tty,
ttysize, tune2fs, udhcpc, udhcpd, udpsvd, umount, uname,
uncompress, unexpand, uniq, unix2dos, unlzma, unzip, uptime,
usleep, uudecode, uuencode, vconfig, vi, vlock, watch, watchdog,
wc, wget, which, who, whoami, xargs, yes, zcat, zcip
COMMAND DESCRIPTIONS
addgroup
addgroup [-g GID] [user_name] group_name
Add a group to the system or add an user to a group
Options:
-g GID Group id
adduser
adduser [OPTIONS] user_name
Add a user to the system
Options:
-h DIR Home directory
-g GECOS GECOS field
-s SHELL Login shell
-G GROUP Add user to existing group
-S Create a system user (ignored)
-D Do not assign a password
-H Do not create home directory
adjtimex
adjtimex [-q] [-o offset] [-f frequency] [-p timeconstant] [-t tick]
Read and optionally set system timebase parameters. See adjtimex(2).
Options:
-q Quiet
-o offset Time offset, microseconds
-f frequency Frequency adjust, integer kernel units (65536 is 1ppm)
(positive values make clock run faster)
-t tick Microseconds per tick, usually 10000
-p timeconstant
ar
ar [-o] [-v] [-p] [-t] [-x] ARCHIVE FILES
Extract or list FILES from an ar archive
Options:
-o Preserve original dates
-p Extract to stdout
-t List
-x Extract
-v Verbose
arp
arp
[-vn]
[-H type] [-i if] -a [hostname]
[-v]
[-i if] -d hostname [pub]
[-v]
[-H type] [-i if] -s hostname hw_addr [temp]
[-v]
[-H type] [-i if] -s hostname hw_addr [netmask nm] pub
[-v]
[-H type] [-i if] -Ds hostname ifa [netmask nm] pub
Manipulate the system ARP cache
Options:
-a Display (all) hosts
-s Set a new ARP entry
-d Delete a specified entry
-v Verbose
-n Don't resolve names
-i if Network interface (e.g. eth0)
-D Read from given device
-A, -p Protocol family
-H hwtype Hardware address type
arping
arping [-fqbDUA] [-c count] [-w timeout] [-i device] [-s sender] target
Ping hosts by ARP requests/replies
Options:
-f Quit on first ARP reply
-q Quiet
-b Keep broadcasting, don't go unicast
-D Duplicated address detection mode
-U Unsolicited ARP mode, update your neighbours
-A ARP answer mode, update your neighbours
-c count Stop after sending count ARP request packets
-w timeout Time to wait for ARP reply, in seconds
-I device Outgoing interface name, default is eth0
-s sender Set specific sender IP address
target Target IP address of ARP request
ash
ash [FILE]... or: ash -c command [args]...
The ash shell (command interpreter)
awk
awk [OPTION]... [program-text] [FILE ...]
Options:
-v var=val Set variable
-F sep Use sep as field separator
-f filename Read program from file
basename
basename FILE [SUFFIX]
Strip directory path and suffixes from FILE. If specified, also remove any trailing SUFFIX.
Example:
$ basename /usr/local/bin/foo
foo
$ basename /usr/local/bin/
bin
$ basename /foo/bar.txt .txt
bar
bbconfig
bbconfig
Print the config file which built busybox
bbsh
bbsh [FILE]... or: bbsh -c command [args]...
The bbsh shell (command interpreter)
bunzip2
bunzip2 [OPTION]... [FILE]
Uncompress FILE (or standard input if FILE is '-' or omitted)
Options:
-c Write output to standard output
-f Force
busybox
busybox
Hello world!
bzcat
bzcat FILE
Uncompress to stdout
cal
cal [-jy] [[month] year]
Display a calendar
Options:
-j Use julian dates
-y Display the entire year
cat
cat [-u] [FILE]...
Concatenate FILE(s) and print them to stdout
Options:
-u Use unbuffered i/o (ignored)
Example:
$ cat /proc/uptime
110716.72 17.67
catv
catv [-etv] [FILE]...
Display nonprinting characters as ^x or M-x
Options:
-e End each line with $
-t Show tabs as ^I
-v Don't use ^x or M-x escapes
chattr
chattr [-R] [-+=AacDdijsStTu] [-v version] files...
Change file attributes on an ext2 fs
Modifiers:
- Remove attributes
+ Add attributes
= Set attributes
Attributes:
A Don't track atime
a Append mode only
c Enable compress
D Write dir contents synchronously
d Do not backup with dump
i Cannot be modified (immutable)
j Write all data to journal first
s Zero disk storage when deleted
S Write file contents synchronously
t Disable tail-merging of partial blocks with other files
u Allow file to be undeleted
Options:
-R Recursively list subdirectories
-v Set the file's version/generation number
chcon
chcon [OPTIONS] CONTEXT FILE...
chcon [OPTIONS] [-u USER] [-r ROLE] [-l RANGE] [-t TYPE] FILE...
chcon [OPTIONS] --reference=RFILE FILE...
Change the security context of each FILE to CONTEXT
-v, --verbose Verbose
-c, --changes Report changes made
-h, --no-dereference Affect symlinks instead of their targets
-f, --silent, --quiet Suppress most error messages
--reference=RFILE Use RFILE's group instead of using a CONTEXT value
-u, --user=USER Set user USER in the target security context
-r, --role=ROLE Set role ROLE in the target security context
-t, --type=TYPE Set type TYPE in the target security context
-l, --range=RANGE Set range RANGE in the target security context
-R, --recursive Recurse subdirectories
chgrp
chgrp [-RhLHPcvf]... GROUP FILE...
Change the group membership of each FILE to GROUP
Options:
-R Recurse directories
-h Affect symlinks instead of symlink targets
-L Traverse all symlinks to directories
-H Traverse symlinks on command line only
-P Do not traverse symlinks (default)
-c List changed files
-v Verbose
-f Hide errors
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
chmod
chmod [-Rcvf] MODE[,MODE]... FILE...
Each MODE is one or more of the letters ugoa, one of the symbols +-= and one or more of the letters rwxst
Options:
-R Recurse directories
-c List changed files
-v List all files
-f Hide errors
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
chown
chown [-RhLHPcvf]... OWNER[[GROUP]] FILE...
Change the owner and/or group of each FILE to OWNER and/or GROUP
Options:
-R Recurse directories
-h Affect symlinks instead of symlink targets
-L Traverse all symlinks to directories
-H Traverse symlinks on command line only
-P Do not traverse symlinks (default)
-c List changed files
-v List all files
-f Hide errors
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
chpasswd
chpasswd [--md5|--encrypt]
Read user:password information from stdin and update /etc/passwd accordingly.
Options:
-e, --encrypt Supplied passwords are in encrypted form
-m, --md5 Use MD5 encryption instead of DES
chpst
chpst [-vP012] [-u user[:group]] [-U user[:group]] [-e dir] [-/ dir] [-n nice] [-m bytes] [-d bytes] [-o files] [-p processes] [-f bytes] [-c bytes] prog args
Change the process state and run specified program
Options:
-u user[:grp] Set uid and gid
-U user[:grp] Set environment variables UID and GID
-e dir Set environment variables as specified by files
in the directory: file=1st_line_of_file
-/ dir Chroot to dir
-n inc Add inc to nice value
-m bytes Limit data segment, stack segment, locked physical pages,
and total of all segment per process to bytes bytes each
-d bytes Limit data segment
-o n Limit the number of open file descriptors per process to n
-p n Limit number of processes per uid to n
-f bytes Limit output file size to bytes bytes
-c bytes Limit core file size to bytes bytes
-v Verbose
-P Run prog in a new process group
-0 Close standard input
-1 Close standard output
-2 Close standard error
chroot
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*
chrt
chrt [OPTION]... [prio] [pid | command [arg]...]
manipulate real-time attributes of a process
Options:
-p operate on pid
-r set scheduling policy to SCHED_RR
-f set scheduling policy to SCHED_FIFO
-o set scheduling policy to SCHED_OTHER
-m show min and max priorities
Example:
$ chrt -r 4 sleep 900; x=$!
$ chrt -f -p 3 $x
You need CAP_SYS_NICE privileges to set scheduling attributes of a process
chvt
chvt N
Change the foreground virtual terminal to /dev/ttyN
cksum
cksum FILES...
Calculate the CRC32 checksums of FILES
clear
clear
Clear screen
cmp
cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]]
Compares FILE1 vs stdin if FILE2 is not specified
Options:
-l Write the byte numbers (decimal) and values (octal)
for all differing bytes
-s Quiet
comm
comm [-123] FILE1 FILE2
Compare FILE1 to FILE2, or to stdin if - is specified
Options:
-1 Suppress lines unique to FILE1
-2 Suppress lines unique to FILE2
-3 Suppress lines common to both files
cp
cp [OPTION]... SOURCE DEST
Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY
Options:
-a Same as -dpR
-c Preserves security context
-d,-P Preserve links
-H,-L Dereference all symlinks (default)
-p Preserve file attributes if possible
-f Force overwrite
-i Prompt before overwrite
-R,-r Recurse directories
-l,-s Create (sym)links
cpio
cpio -[dimtuv][F cpiofile]
Extract or list files from a cpio archive Main operation mode:
d Make leading directories
i Extract
m Preserve mtime
t List
v Verbose
u Unconditional overwrite
F Input from file
crond
crond -d[#] -c crondir -f -b
-d [#] -l [#] -S -L logfile -f -b -c dir
-d num Debug level
-l num Log level (8 - default)
-S Log to syslogd (default)
-L file Log to file
-f Run in foreground
-b Run in background (default)
-c dir Working dir
crontab
crontab [-c dir] {file|-}|[-u|-l|-e|-d user]
file [opts] Replace crontab from file
- [opts] Replace crontab from stdin
-u user User
-l [user] List crontab for user
-e [user] Edit crontab for user
-d [user] Delete crontab for user
-c dir Crontab directory
cryptpw
cryptpw [-a des|md5] [string]
Outputs crypted string. If string isn't supplied on cmdline, reads it from stdin.
Options:
-a Algorithm to use (default: md5)
cut
cut [OPTION]... [FILE]...
Print selected fields from each input FILE to standard output
Options:
-b LIST Output only bytes from LIST
-c LIST Output only characters from LIST
-d CHAR Use CHAR instead of tab as the field delimiter
-s Output only the lines containing delimiter
-f N Print only these fields
-n Ignored
Example:
$ echo "Hello world" | cut -f 1 -d ' '
Hello
$ echo "Hello world" | cut -f 2 -d ' '
world
date
date [OPTION]... [MMDDhhmm[[CC]YY][.ss]] [+FORMAT]
Display current time in the given FORMAT, or set system date
Options:
-R Outputs RFC-822 compliant date string
-d STRING Displays time described by STRING, not 'now'
-I[TIMESPEC] Outputs an ISO-8601 compliant date/time string
TIMESPEC='date' (or missing) for date only,
'hours', 'minutes', or 'seconds' for date and
time to the indicated precision
-D hint Use 'hint' as date format, via strptime()
-s STRING Sets time described by STRING
-r FILE Displays the last modification time of FILE
-u Prints or sets Coordinated Universal Time
Example:
$ date
Wed Apr 12 18:52:41 MDT 2000
dc
dc expression ...
This is a Tiny RPN calculator that understands the following operations: +, add, -, sub, *, mul, /, div, %, mod, **, exp, and, or, not, eor. For example: 'dc 2 2 add' -> 4, and 'dc 8 8 \* 2 2 + /' -> 16.
Options: p - Prints the value on the top of the stack, without altering the stack f - Prints the entire contents of the stack without altering anything o - Pops the value off the top of the stack and uses it to set the output radix
Only 10 and 16 are supported
Example:
$ dc 2 2 + p
4
$ dc 8 8 \* 2 2 + / p
16
$ dc 0 1 and p
0
$ dc 0 1 or p
1
$ echo 72 9 div 8 mul p | dc
64
dd
dd [if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N] [skip=N]
[seek=N] [conv=notrunc|noerror|sync]
Copy a file with converting and formatting
Options:
if=FILE Read from FILE instead of stdin
of=FILE Write to FILE instead of stdout
bs=N Read and write N bytes at a time
ibs=N Read N bytes at a time
obs=N Write N bytes at a time
count=N Copy only N input blocks
skip=N Skip N input blocks
seek=N Skip N output blocks
conv=notrunc Don't truncate output file
conv=noerror Continue after read errors
conv=sync Pad blocks with zeros
Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024), MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)
Example:
$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4
4+0 records in
4+0 records out
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 USER
Delete user USER from the system
devfsd
devfsd mntpnt [-v][-fg][-np]
Manage devfs permissions and old device name symlinks
Options:
mntpnt The mount point where devfs is mounted
-v Print the protocol version numbers for devfsd
and the kernel-side protocol version and exit
-fg Run in foreground
-np Exit after parsing the configuration file
and processing synthetic REGISTER events,
do not poll for events
df
df [-hmk] [FILESYSTEM ...]
Print the filesystem space used and space available
Options control size display:
-h Human readable (e.g. 1K 243M 2G)
-m 1024*1024 blocks
-k 1024 blocks
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% /
dhcprelay
dhcprelay [client_device_list] [server_device]
Relay dhcp requests from client devices to server device
diff
diff [-abdiNqrTstw] [-L LABEL] [-S FILE] [-U LINES] FILE1 FILE2
Compare files line by line and output the differences between them. This diff implementation only supports unified diffs.
Options:
-a Treat all files as text
-b Ignore changes in the amount of whitespace
-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 Recursively compare subdirectories
-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
Example:
$ dirname /tmp/foo
/tmp
$ dirname /tmp/foo/
/tmp
dmesg
dmesg [-c] [-n LEVEL] [-s SIZE]
Print or control the kernel ring buffer
Options:
-c Clears the ring buffer's contents after printing
-n LEVEL Sets console logging level
-s SIZE Use a buffer of size SIZE
dnsd
dnsd [-c config] [-t seconds] [-p port] [-i iface-ip] [-d]
Small and static DNS server daemon
Options:
-c Config filename
-t TTL in seconds
-p Listening port
-i Listening ip (default all)
-d Daemonize
dos2unix
dos2unix [option] [FILE]
Convert FILE from dos format to unix format. When no option is given, the input is converted to the opposite output format. When no file is given, use stdin for input and stdout for output.
Options:
-u Output will be in UNIX format
-d Output will be in DOS format
dpkg
dpkg [-ilCPru] [-F option] package_name
Install, remove and manage Debian packages
Options:
-i Install the package
-l List of installed packages
-C Configure an unpackaged package
-F depends Ignore dependency problems
-P Purge all files of a package
-r Remove all but the configuration files for a package
-u Unpack a package, but don't configure it
dpkg-deb
dpkg-deb [-cefxX] FILE [argument]
Perform actions on Debian packages (.debs)
Options:
-c List contents of filesystem tree
-e Extract control files to [argument] directory
-f Display control field name starting with [argument]
-x Extract packages filesystem tree to directory
-X Verbose extract
Example:
$ dpkg-deb -X ./busybox_0.48-1_i386.deb /tmp
du
du [-aHLdclsxhmk] [FILE]...
Summarize disk space used for each FILE and/or directory. Disk space is printed in units of 1024 bytes.
Options:
-a Show sizes of files in addition to directories
-H Follow symlinks that are FILE command line args
-L Follow all symlinks encountered
-d N Limit output to directories (and files with -a) of depth
Example:
$ 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 .
dumpkmap
dumpkmap > keymap
Print out a binary keyboard translation table to standard output
Example:
$ dumpkmap > keymap
dumpleases
dumpleases [-r|-a] [-f LEASEFILE]
Display DHCP leases granted by udhcpd
Options:
-f, --file=FILENAME Leases file to load
-r, --remaining Interpret lease times as time remaining
-a, --absolute Interpret lease times as expire time
e2fsck
e2fsck [-panyrcdfvstDFSV] [-b superblock] [-B blocksize] [-I inode_buffer_blocks] [-P process_inode_size] [-l|-L bad_blocks_file] [-C fd] [-j external_journal] [-E extended-options] device
Check ext2/ext3 file system
Options:
-p Automatic repair (no questions)
-n Make no changes to the filesystem
-y Assume 'yes' to all questions
-c Check for bad blocks and add them to the badblock list
-f Force checking even if filesystem is marked clean
-v Verbose
-b superblock Use alternative superblock
-B blocksize Force blocksize when looking for superblock
-j journal Set location of the external journal
-l file Add to badblocks list
-L file Set badblocks list
echo
echo [-neE] [ARG ...]
Print the specified ARGs to stdout
Options:
-n Suppress trailing newline
-e Interpret backslash-escaped characters (i.e., \t=tab)
-E Disable interpretation of backslash-escaped characters
Example:
$ echo "Erik is cool"
Erik is cool
$ echo -e "Erik\nis\ncool"
Erik
is
cool
$ echo "Erik\nis\ncool"
Erik\nis\ncool
ed
ed #define ed_full_usage
eject
eject [-t] [-T] [DEVICE]
Eject specified DEVICE (or default /dev/cdrom)
Options:
-t Close tray
-T Open/close tray (toggle)
env
env [-iu] [-] [name=value]... [command]
Print the current environment or run a program after setting up the specified environment
Options:
-, -i Start with an empty environment
-u Remove variable from the environment
envdir
envdir dir prog args
Set various environment variables as specified by files in the directory dir, then run prog
envuidgid
envuidgid account prog args
Set $UID to account's uid and $GID to account's gid, then run prog
ether_wake
ether_wake [-b] [-i iface] [-p aa:bb:cc:dd[:ee:ff]] MAC
Send a magic packet to wake up sleeping machines. MAC must be a station address (00:11:22:33:44:55) or a hostname with a known 'ethers' entry.
Options:
-b Send wake-up packet to the broadcast address
-i iface Use interface ifname instead of the default "eth0"
-p pass Append the four or six byte password PW to the packet
expand
expand [-i] [-t NUM] [FILE|-]
Convert tabs to spaces, writing to standard output.
Options:
-i,--initial Do not convert tabs after non blanks
-t,--tabs=N Tabstops every N chars
expr
expr EXPRESSION
Print the value of EXPRESSION to standard output.
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 ARG1 is greater than or equal to ARG2
ARG1 > ARG2 ARG1 is greater than ARG2
ARG1 + ARG2 Sum of ARG1 and ARG2
ARG1 - ARG2 Difference of ARG1 and ARG2
ARG1 * ARG2 Product of ARG1 and ARG2
ARG1 / ARG2 Quotient of ARG1 divided by ARG2
ARG1 % ARG2 Remainder of ARG1 divided by ARG2
STRING : REGEXP Anchored pattern match of REGEXP in STRING
match STRING REGEXP Same as STRING : REGEXP
substr STRING POS LENGTH Substring of STRING, POS counted from 1
index STRING CHARS Index in STRING where any CHARS is found, or 0
length STRING Length of STRING
quote TOKEN Interpret TOKEN as a string, even if
it is a keyword like 'match' or an
operator like '/'
(EXPRESSION) Value of EXPRESSION
Beware that many operators need to be escaped or quoted for shells. Comparisons are arithmetic if both ARGs are numbers, else lexicographical. Pattern matches return the string matched between \( and \) or null; if \( and \) are not used, they return the number of characters matched or 0.
fakeidentd
fakeidentd [-fiw] [-b ADDR] [STRING]
Provide fake ident (auth) service
Options:
-f Run in foreground
-i Inetd mode
-w Inetd 'wait' mode
-b ADDR Bind to specified address
STRING Ident answer string (default is 'nobody')
false
false
Return an exit code of FALSE (1)
Example:
$ false
$ echo $?
1
fbset
fbset [options] [mode]
Show and modify frame buffer settings
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
fdflush
fdflush DEVICE
Force floppy disk drive to detect disk change
fdformat
fdformat [-n] DEVICE
Format floppy disk
Options:
-n Don't verify after format
fdisk
fdisk [-luv] [-C CYLINDERS] [-H HEADS] [-S SECTORS] [-b SSZ] DISK
Change partition table
Options:
-l List partition table(s)
-u Give Start and End in sector (instead of cylinder) units
-s PARTITION Give partition size(s) in blocks
-b 2048 (for certain MO disks) use 2048-byte sectors
-C CYLINDERS Set the number of cylinders
-H HEADS Set the number of heads
-S SECTORS Set the number of sectors
-v Give fdisk version
find
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 symlinks
-xdev Don't descend directories on other filesystems
-maxdepth N Descend at most N levels. -maxdepth 0 applies
tests/actions to command line arguments only
-name PATTERN File name (w/o directory name) matches PATTERN
-path PATTERN Path matches PATTERN
-regex PATTERN Path matches regex PATTERN
-type X File type is X (X is one of: f,d,l,b,c,...)
-perm NNN Permissions match any of (+NNN), all of (-NNN),
or exactly (NNN)
-mtime DAYS Modified time is greater than (+N), less than (-N),
or exactly (N) days
-mmin MINS Modified time is greater than (+N), less than (-N),
or exactly (N) minutes
-newer FILE Modified time is more recent than FILE's
-inum N File has inode number N
-user NAME File is owned by user NAME (numeric user ID allowed)
-group NAME File belongs to group NAME (numeric group ID allowed)
-depth Process directory name after traversing it
-size N[bck] File size is N (c:bytes,k:kbytes,b:512 bytes(def.)).
+/-N: file size is bigger/smaller than N
-print Print (default and assumed)
-print0 Delimit output with null characters rather than
newlines USE_FEATURE_FIND_CONTEXT (
-context File has specified security context")
-exec CMD ARG ; Execute CMD with all instances of {} replaced by the
matching files
-prune Stop traversing current subtree
-delete Delete files, turns on -depth option
(EXPR) Group an expression
Example:
$ find / -name passwd
/etc/passwd
fold
fold [-bs] [-w WIDTH] [FILE]
Wrap input lines in each FILE (standard input by default), writing to standard output
Options:
-b Count bytes rather than columns
-s Break at spaces
-w Use WIDTH columns instead of 80
free
free
Display the amount of free and used system memory
Example:
$ free
total used free shared buffers
Mem: 257628 248724 8904 59644 93124
Swap: 128516 8404 120112
Total: 386144 257128 129016
freeramdisk
freeramdisk DEVICE
Free all memory used by the specified ramdisk
Example:
$ freeramdisk /dev/ram2
fsck
fsck [-ANPRTV] [-C fd] [-t fstype] [fs-options] [filesys ...]
Check and repair filesystems
Options:
-A Walk /etc/fstab and check all filesystems
-N Don't execute, just show what would be done
-P When using -A, check filesystems in parallel
-R When using -A, skip the root filesystem
-T Don't show title on startup
-V Verbose
-C n Write status information to specified filedescriptor
-t type List of filesystem types to check
fsck.minix
fsck.minix [-larvsmf] /dev/name
Perform 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
ftpget
ftpget [options] remote-host local-file remote-file
Retrieve a remote file via FTP
Options:
-c, --continue Continue a previous transfer
-v, --verbose Verbose
-u, --username Username to be used
-p, --password Password to be used
-P, --port Port number to be used
ftpput
ftpput [options] remote-host remote-file local-file
Store a local file on a remote machine via FTP
Options:
-v, --verbose Verbose
-u, --username Username to be used
-p, --password Password to be used
-P, --port Port number to be used
fuser
fuser [options] file OR port/proto
Options:
-m Show all processes on the same mounted fs
-k Kill all processes that match
-s Don't print or kill anything
-4 When using port/proto only search IPv4 space
-6 When using port/proto only search IPv6 space
-SIGNAL When used with -k, this signal will be used to kill
getenforce
getenforce #define getenforce_full_usage
getopt
getopt [OPTIONS]...
Parse command options
-a, --alternative Allow long options starting with single -
-l, --longoptions=longopts Long options to be recognized
-n, --name=progname The name under which errors are reported
-o, --options=optstring Short options to be recognized
-q, --quiet Disable error reporting by getopt(3)
-Q, --quiet-output No normal output
-s, --shell=shell Set shell quoting conventions
-T, --test Test for getopt(1) version
-u, --unquoted Do not quote the output
Example:
$ cat getopt.test
#!/bin/sh
GETOPT=`getopt -o ab:c:: --long a-long,b-long:,c-long:: \
-n 'example.busybox' -- "$@"`
if [ $? != 0 ]; then exit 1; fi
eval set -- "$GETOPT"
while true; do
case $1 in
-a|--a-long) echo "Option a"; shift;;
-b|--b-long) echo "Option b, argument '$2'"; shift 2;;
-c|--c-long)
case "$2" in
"") echo "Option c, no argument"; shift 2;;
*) echo "Option c, argument '$2'"; shift 2;;
esac;;
--) shift; break;;
*) echo "Internal error!"; exit 1;;
esac
done
getsebool
getsebool -a or getsebool boolean...
-a Show all SELinux booleans
getty
getty [OPTIONS]... baud_rate,... line [termtype]
Open a tty, prompt for a login name, then invoke /bin/login
Options:
-h Enable hardware (RTS/CTS) flow control
-i Do not display /etc/issue before running login
-L Local line, so do not do carrier detect
-m Get baud rate from modem's CONNECT status message
-w Wait for a CR or LF before sending /etc/issue
-n Do not prompt the user for a login name
-f issue_file Display issue_file instead of /etc/issue
-l login_app Invoke login_app instead of /bin/login
-t timeout Terminate after timeout if no username is read
-I initstring Sets the init string to send before anything else
-H login_host Log login_host into the utmp file as the hostname
grep
grep [-HhrilLnqvsoweFEABC] PATTERN [FILEs...]
Search for PATTERN in each FILE or standard input
Options:
-H Prefix output lines with filename where match was found
-h Suppress the prefixing filename on output
-r Recurse subdirectories
-i Ignore case distinctions
-l List names of files that match
-L List names of files that do not match
-n Print line number with output lines
-q Quiet. Returns 0 if PATTERN was found, 1 otherwise
-v Select non-matching lines
-s Suppress file open/read error messages
-c Only print count of matching lines
-o Show only the part of a line that matches PATTERN
-m MAX Match up to MAX times per file
-w Match whole words only
-F PATTERN is a set of newline-separated strings
-E PATTERN is an extended regular expression
-e PTRN Pattern to match
-f FILE Read pattern from file
-A Print NUM lines of trailing context
-B Print NUM lines of leading context
-C Print NUM lines of output context
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
gunzip
gunzip [OPTION]... FILE
Uncompress FILE (or standard input if FILE is '-')
Options:
-c Write output to standard output
-f Force read when source is a terminal
-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
gzip
gzip [OPTION]... [FILE]...
Compress FILE(s) with maximum compression. When FILE is '-' or unspecified, reads standard input. Implies -c.
Options:
-c Write output to standard output instead of FILE.gz
-d Decompress
-f Force write when destination is a terminal
Example:
$ ls -la /tmp/busybox*
-rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/busybox.tar
$ gzip /tmp/busybox.tar
$ ls -la /tmp/busybox*
-rw-rw-r-- 1 andersen andersen 554058 Apr 14 17:49 /tmp/busybox.tar.gz
halt
halt [-d delay] [-n] [-f]
Halt the system
Options:
-d Delay interval for halting
-n No call to sync()
-f Force halt (don't go through init)
hdparm
hdparm [options] [device] ..
If no device name is specified try to read from stdin.
Options:
-a Get/set fs readahead
-A Set drive read-lookahead flag (0/1)
-b Get/set bus state (0 == off, 1 == on, 2 == tristate)
-B Set Advanced Power Management setting (1-255)
-c Get/set IDE 32-bit IO setting
-C Check IDE power mode status
-d 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 Change next setting quietly
-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 Un-register 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 Re-read partition table
head
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
-c NUM Output the first NUM bytes
-q Never output headers giving file names
-v Always output headers giving file names
Example:
$ head -n 2 /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
hexdump
hexdump [-[bcCdefnosvx]] [OPTION] FILE
Display file(s) or standard input in a user specified format
Options:
-b One-byte octal display
-c One-byte character display
-C Canonical hex+ASCII, 16 bytes per line
-d Two-byte decimal display
-e FORMAT STRING
-f FORMAT FILE
-n LENGTH Interpret only length bytes of input
-o Two-byte octal display
-s OFFSET Skip offset bytes
-v Display all input data
-x Two-byte hexadecimal display
hostid
hostid
Print out a unique 32-bit identifier for the machine
hostname
hostname [OPTION] {hostname | -F FILE}
Get or set the hostname or DNS domain name. If a hostname is given (or FILE with the -F parameter), the host name will be set.
Options:
-s Short
-i Addresses for the hostname
-d DNS domain name
-f Fully qualified domain name
-F FILE Use the contents of FILE to specify the hostname
Example:
$ hostname
sage
httpd
httpd [-c conffile] [-p [ip:]port] [-i] [-f] [-v[v]] [-u user[:grp]] [-r realm] [-m pass] [-h home] [-d/-e string]
Listen for incoming HTTP requests
Options:
-c FILE Configuration file (default httpd.conf)
-p [IP:]PORT Bind to ip:port (default *:80)
-i Inetd mode
-f Do not daemonize
-v[v] Verbose
-u USER[:GRP] Set uid/gid after binding to port
-r REALM Authentication Realm for Basic Authentication
-m PASS Crypt PASS with md5 algorithm
-h HOME Home directory (default .)
-e STRING HTML encode STRING
-d STRING URL decode STRING
hwclock
hwclock [-r|--show] [-s|--hctosys] [-w|--systohc] [-l|--localtime] [-u|--utc] [-f FILE]
Query and set a hardware clock (RTC)
Options:
-r Read hardware clock and print result
-s Set the system time from the hardware clock
-w Set the hardware clock to the current system time
-u The hardware clock is kept in coordinated universal time
-l The hardware clock is kept in local time
-f FILE Use the specified clock (e.g. /dev/rtc2)
id
id [OPTIONS]... [USERNAME]
Print information for USERNAME or the current user
Options:
-Z prints only the security context
-g Prints only the group ID
-u Prints only the user ID
-n Print a name instead of a number
-r Prints the real user ID instead of the effective ID
Example:
$ id
uid=1000(andersen) gid=1000(andersen)
ifconfig
ifconfig [-a] interface [address]
Configure a network interface
Options:
[add ADDRESS[/PREFIXLEN]]
[del ADDRESS[/PREFIXLEN]]
[[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]]
[netmask ADDRESS] [dstaddr ADDRESS]
[outfill NN] [keepalive NN]
[hw ether 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 [-ahinv] ifaces...
Options:
-a De/configure all interfaces automatically
-i FILE Use FILE for interface definitions
-n Print out what would happen, but don't do it
(note that this option doesn't disable mappings)
-v Print out what would happen before doing it
-m Don't run any mappings
-f Force de/configuration
ifup
ifup [-ahinv] ifaces...
Options:
-a De/configure all interfaces automatically
-i FILE Use FILE for interface definitions
-n Print out what would happen, but don't do it
(note that this option doesn't disable mappings)
-v Print out what would happen before doing it
-m Don't run any mappings
-f Force de/configuration
inetd
inetd [-f] [-q len] [conf]
Listen for network connections and launch programs
Options:
-f Run in foreground
-q N Set the size of the socket listen queue to N
(default: 128)
init
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
::ctrlaltdel:/sbin/reboot
::shutdown:/sbin/swapoff -a
::shutdown:/bin/umount -a -r
::restart:/sbin/init
if it detects that /dev/console is _not_ a serial console, it will also run:
tty2::askfirst:/bin/sh
tty3::askfirst:/bin/sh
tty4::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, the controlling tty is set to the console. Also
note that if BusyBox detects that a serial console is in use, then only
entries whose controlling tty is either the serial console or /dev/null
will 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, restart, ctrlaltdel, and shutdown.
The available actions can be classified into two groups: actions
that are run only once, and actions that are re-run when the specified
process exits.
Run only-once actions:
'sysinit' is the first item run on boot. init waits until all
sysinit actions are completed before continuing. Following the
completion of all sysinit actions, all 'wait' actions are run.
'wait' actions, like 'sysinit' actions, cause init to wait until
the specified task completes. 'once' actions are asynchronous,
therefore, init does not wait for them to complete. 'restart' is
the action taken to restart the init process. By default this should
simply run /sbin/init, but can be a script which runs pivot_root or it
can do all sorts of other interesting things. The 'ctrlaltdel' init
actions are run when the system detects that someone on the system
console has pressed the CTRL-ALT-DEL key combination. Typically one
wants to run 'reboot' at this point to cause the system to reboot.
Finally the 'shutdown' action specifies the actions to taken when
init is told to reboot. Unmounting filesystems and disabling swap
is a very good here.
Run repeatedly actions:
'respawn' actions are run after the 'once' actions. When a process
started with a 'respawn' action exits, init automatically restarts
it. Unlike sysvinit, BusyBox init does not stop processes from
respawning out of control. The 'askfirst' actions acts just like
respawn, except that 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.
Unrecognized actions (like initdefault) will cause init to emit an
error message, and then go along with its business. All actions are
run in the order they appear in /etc/inittab.
:
Specifies the process to be executed and its 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/tty2-4
tty2::askfirst:-/bin/sh
tty3::askfirst:-/bin/sh
tty4::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)
#
#::respawn:/sbin/getty -L ttyS0 9600 vt100
#::respawn:/sbin/getty -L ttyS1 9600 vt100
#
# Example how to put a getty on a modem line
#::respawn:/sbin/getty 57600 ttyS2
# Stuff to do when restarting the init process
::restart:/sbin/init
# Stuff to do before rebooting
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
::shutdown:/sbin/swapoff -a
insmod
insmod [OPTION]... MODULE [symbol=value]...
Load the specified kernel modules into the kernel
Options:
-f Force module to load into the wrong kernel version
-k Make module autoclean-able
-v Verbose
-q Quiet
-L Lock to prevent simultaneous loads of a module
-m Output load map to stdout
-o NAME Set internal module name to NAME
-x Do not export externs
install
install [-cgmops] [sources] dest|directory
Copy files and set attributes
Options:
-c Copy the file, default
-d Create directories
-g Set group ownership
-m Set permissions
-o Set ownership
-p Preserve date
-s Strip symbol tables
-Z Set security context of copy
ip
ip [OPTIONS] {address | route | link | tunnel | rule} {COMMAND}
ip [OPTIONS] OBJECT {COMMAND} where OBJECT := {address | route | link | tunnel | rule} OPTIONS := { -f[amily] { inet | inet6 | link } | -o[neline] }
ipaddr
ipaddr { {add|del} IFADDR dev STRING | {show|flush}
[dev STRING] [to PREFIX] }
ipaddr {add|delete} IFADDR dev STRING ipaddr {show|flush} [dev STRING] [scope SCOPE-ID]
[to PREFIX] [label PATTERN]
IFADDR := PREFIX | ADDR peer PREFIX
[broadcast ADDR] [anycast ADDR]
[label STRING] [scope SCOPE-ID]
SCOPE-ID := [host | link | global | NUMBER]
ipcalc
ipcalc [OPTION]... ADDRESS[[/]NETMASK] [NETMASK]
Calculate IP network settings from a IP address
Options:
-b --broadcast Display calculated broadcast address
-n --network Display calculated network address
-m --netmask Display default netmask for IP
-p --prefix Display the prefix for IP/NETMASK
-h --hostname Display first resolved host name
-s --silent Don't ever display error messages
ipcrm
ipcrm [-[MQS] key] [-[mqs] id]
The upper-case options MQS are used to remove a shared memory segment by a segment by a shmkey value. The lower-case options mqs are used to remove a segment by shmid value.
Options:
-[mM] Remove the memory segment after the last detach
-[qQ] Remove the message queue
-[sS] Remove the semaphore
ipcs
ipcs [[-smq] -i shmid] | [[-asmq] [-tcplu]]
-i Show a 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
iplink set DEVICE { up | down | arp | multicast { on | off } |
dynamic { on | off } |
mtu MTU }
iplink show [DEVICE]
iproute
iproute { list | flush | { add | del | change | append |
replace | monitor } ROUTE }
iproute { list | flush } SELECTOR iproute get ADDRESS [from ADDRESS iif STRING]
[oif STRING] [tos TOS]
iproute { add | del | change | append | replace | monitor } ROUTE
SELECTOR := [root PREFIX] [match PREFIX] [proto RTPROTO]
ROUTE := [TYPE] PREFIX [tos TOS] [proto RTPROTO]
iprule
iprule {[list | add | del] RULE}
iprule [list | add | del] SELECTOR ACTION
SELECTOR := [from PREFIX] [to PREFIX] [tos TOS] [fwmark FWMARK]
[dev STRING] [pref NUMBER]
ACTION := [table TABLE_ID] [nat ADDRESS]
[prohibit | reject | unreachable]
[realms [SRCREALM/]DSTREALM]
TABLE_ID := [local | main | default | NUMBER]
iptunnel
iptunnel { add | change | del | show } [NAME]
[mode { ipip | gre | sit }]
[remote ADDR] [local ADDR] [ttl TTL]
iptunnel { add | change | del | show } [NAME]
[mode { ipip | gre | sit }] [remote ADDR] [local ADDR]
[[i|o]seq] [[i|o]key KEY] [[i|o]csum]
[ttl TTL] [tos TOS] [[no]pmtudisc] [dev PHYS_DEV]
kill
kill [-l] [-signal] process-id [process-id ...]
Send a signal (default is TERM) 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
killall
killall [-l] [-q] [-signal] process-name [process-name ...]
Send a signal (default is TERM) to the specified process(es)
Options:
-l List all signal names and numbers
-q Do not complain if no processes were killed
Example:
$ killall apache
killall5
killall5 [-l] [-signal]
Send a signal (default is TERM) to all processes outside current session
Options:
-l List all signal names and numbers
klogd
klogd [-c n] [-n]
Kernel logger
Options:
-c n Sets the default log level of console messages to n
-n Run in foreground
lash
lash [FILE]... or: sh -c command [args]...
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, 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.
last
last
Show listing of the last users that logged into the system
length
length STRING
Print out the length of the specified STRING
Example:
$ length Hello
5
less
less [-EMNmh~?] FILE1 FILE2...
View a file or list of files. The position within files can be changed, and files can be manipulated in various ways.
Options:
-E Quit once the end of a file is reached
-M,-m Display a status line containing the current line numbers
and the percentage through the file
-N Prefix line numbers to each line
-~ Suppress ~s displayed when input past the end of the file is
reached
ln
ln [OPTION] TARGET... LINK_NAME|DIRECTORY
Create a link named LINK_NAME or DIRECTORY to the specified TARGET. You may use '--' to indicate that all following arguments are non-options.
Options:
-s Make symlinks instead of hardlinks
-f Remove existing destination files
-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
Example:
$ ln -s BusyBox /tmp/ls
$ ls -l /tmp/ls
lrwxrwxrwx 1 root root 7 Apr 12 18:39 ls -> BusyBox*
load_policy
load_policy
loadfont
loadfont
Load a console font from standard input
Example:
$ loadfont
loadkmap
loadkmap
Load a binary keyboard translation table from standard input
Example:
$ loadkmap
logger
logger [OPTION]... [MESSAGE]
Write MESSAGE to the system log. If MESSAGE is omitted, log stdin.
Options:
-s Log to stderr as well as the system log
-t TAG Log using the specified tag (defaults to user name)
-p PRIO Enter the message with the specified priority.
This may be numerical or a 'facility.level' pair.
Example:
$ logger "hello"
login
login [OPTION]... [username] [ENV=VAR ...]
Begin a new session on the system
Options:
-f Do not authenticate (user already authenticated)
-h Name of the remote host for this login
-p Preserve environment
logname
logname
Print the name of the current user
Example:
$ logname
root
logread
logread [OPTION]...
Show the messages from syslogd (using circular buffer)
Options:
-f Output data as the log grows
losetup
losetup [-o OFS] LOOPDEV FILE - associate loop devices
losetup -d LOOPDEV - disassociate
losetup [-f] - show
Options:
-o OFS Start OFS bytes into FILE
-f Show first free loop device
No arguments will display all current associations. One argument (losetup /dev/loop1) will display the current association (if any), or disassociate it (with -d). The display shows the offset and filename of the file the loop device is currently bound to.
Two arguments (losetup /dev/loop1 file.img) create a new association, with an optional offset (-o 12345). Encryption is not yet supported. losetup -f will show the first loop free loop device
ls
ls [-1AacCdeFilnpLRrSsTtuvwxXhkK] [filenames...]
List directory contents
Options:
-1 List files in a single column
-A Do not list implied . and ..
-a Do not hide entries starting with .
-C List entries by columns
-c With -l: show ctime
--color[={always,never,auto}] Control coloring
-d List directory entries instead of contents
-e List both full date and full time
-F Append indicator (one of */=@|) to entries
-i List the i-node for each file
-l Use a long listing format
-n List numeric UIDs and GIDs instead of names
-p Append indicator (one of /=@|) to entries
-L List entries pointed to by symlinks
-R List subdirectories recursively
-r Sort the listing in reverse order
-S Sort the listing by file size
-s List the size of each file, in blocks
-T NUM Assume Tabstop every NUM columns
-t With -l: show modification time
-u With -l: show access time
-v Sort the listing by version
-w NUM Assume the terminal is NUM columns wide
-x List entries by lines instead of by columns
-X Sort the listing by extension
-h Print sizes in human readable format (e.g., 1K 243M 2G)
-k Print security context
-K Print security context in long format
-Z Print security context and permission
lsattr
lsattr [-Radlv] [files...]
List file attributes on an ext2 fs
Options:
-R Recursively list subdirectories
-a Do not hide entries starting with .
-d List directory entries instead of contents
-l Print long flag names
-v List the file's version/generation number
lsmod
lsmod
List the currently loaded kernel modules
lzmacat
lzmacat FILE
Uncompress to stdout
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: Where name is the file name, type can be one of:
f A regular file
d Directory
c Character special device file
b Block special device file
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.
Example:
For example:
/dev d 755 0 0 - - - - -
/dev/console c 666 0 0 5 1 - - -
/dev/null c 666 0 0 1 3 0 0 -
/dev/zero c 666 0 0 1 5 0 0 -
/dev/hda b 640 0 0 3 0 0 0 -
/dev/hda b 640 0 0 3 1 1 1 15
Will Produce:
/dev
/dev/console
/dev/null
/dev/zero
/dev/hda
/dev/hda[0-15]
matchpathcon
matchpathcon [-n] [-N] [-f file_contexts_file] [-p prefix] [-V]
-n Do not display path
-N Do not use translations
-f Use alternate file_context file
-p Use prefix to speed translations
-V Verify file context on disk matches defaults
md5sum
md5sum [OPTION] [FILEs...] or: md5sum [OPTION] -c [FILE]
Print or check MD5 checksums
Options: With no FILE, or when FILE is -, read standard input.
-c Check MD5 sums against given list
The following two options are useful only when verifying checksums:
-s Don't output anything, status code shows success
-w Warn about improperly formatted MD5 checksum lines
Example:
$ md5sum
mdev
mdev [-s]
-s Scan /sys and populate /dev during system boot
Called with no options (via hotplug) it uses environment variables to determine which device to add/remove.
The mdev config file contains lines that look like:
hd[a-z][0-9]* 0:3 660
That's device name (with regex match), uid:gid, and permissions.
Optionally, that can be followed (on the same line) by a special character and a command line to run after creating/before deleting the corresponding device(s). The environment variable $MDEV indicates the active device node (which is useful if it's a regex match). For example:
hdc root:cdrom 660 *ln -s $MDEV cdrom
The special characters are @ (run after creating), $ (run before deleting), and * (run both after creating and before deleting). The commands run in the /dev directory, and use system() which calls /bin/sh.
Config file parsing stops on the first matching line. If no config entry is matched, devices are created with default 0:0 660. (Make the last line match .* to override this.)
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 [-s speed] tty-name
mkdir
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 existing, make parent directories as needed
-Z Set security context
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
mke2fs
mke2fs [-c|-l filename] [-b block-size] [-f fragment-size] [-g blocks-per-group] [-i bytes-per-inode] [-j] [-J journal-options] [-N number-of-inodes] [-n] [-m reserved-blocks-percentage] [-o creator-os] [-O feature[,...]] [-q] [r fs-revision-level] [-E extended-options] [-v] [-F] [-L volume-label] [-M last-mounted-directory] [-S] [-T filesystem-type] device [blocks-count]
-b size Block size in bytes
-c Check for bad blocks before creating
-E opts Set extended options
-f size Fragment size in bytes
-F Force (ignore sanity checks)
-g num Number of blocks in a block group
-i ratio The bytes/inode ratio
-j Create a journal (ext3)
-J opts Set journal options (size/device)
-l file Read bad blocks list from file
-L lbl Set the volume label
-m percent Percent of fs blocks to reserve for admin
-M dir Set last mounted directory
-n Do not actually create anything
-N num Number of inodes to create
-o os Set the 'creator os' field
-O features Dir_index/filetype/has_journal/journal_dev/sparse_super
-q Quiet
-r rev Set filesystem revision
-S Write superblock and group descriptors only
-T fs-type Set usage type (news/largefile/largefile4)
-v Verbose
mkfifo
mkfifo [OPTIONS] name
Create a named pipe (identical to 'mknod name p')
Options:
-m Create the pipe using the specified mode (default a=rw)
-Z Set security context
mkfs.minix
mkfs.minix [-c | -l filename] [-nXX] [-iXX] /dev/name [blocks]
Make a MINIX filesystem
Options:
-c Check device for bad blocks
-n [14|30] Maximum length of filenames
-i INODES Number of inodes for the filesystem
-l FILENAME Read bad blocks list from FILENAME
-v Make a Minix version 2 filesystem
mknod
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
-Z Set security context
Example:
$ mknod /dev/fd0 b 2 0
$ mknod -m 644 /tmp/pipe p
mkswap
mkswap [-c] [-v0|-v1] device [block-count]
Prepare a disk partition to be used as 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)
mktemp
mktemp [-dq] TEMPLATE
Create a temporary file with its name based on TEMPLATE. TEMPLATE is any name with six 'Xs' (i.e., /tmp/temp.XXXXXX).
Options:
-d Make a directory instead of a file
-q Fail silently if an error occurs
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
modprobe
modprobe [-knqrsv] MODULE [symbol=value ...]
Options:
-k Make module autoclean-able
-n Just show what would be done
-q Quiet
-r Remove module (stacks) or do autoclean
-s Report via syslog instead of stderr
-v Verbose
modprobe can (un)load a stack of modules, passing each module options (when loading). modprobe uses a configuration file to determine what option(s) to pass each module it loads.
The configuration file is searched (in order) amongst:
/etc/modprobe.conf (2.6 only)
/etc/modules.conf
/etc/conf.modules (deprecated)
They all have the same syntax (see below). If none is present, it is _not_ an error; each loaded module is then expected to load without options. Once a file is found, the others are tested for.
/etc/modules.conf entry format:
alias
Makes it possible to modprobe alias_name, when there is no such module.
It makes sense if your mod_name is long, or you want a more representative
name for that module (eg. 'scsi' in place of 'aha7xxx').
This makes it also possible to use a different set of options (below) for
the module and the alias.
A module can be aliased more than once.
options
When loading module mod_name (or the module aliased by alias_name), pass
the "symbol=value" pairs as option to that module.
Sample /etc/modules.conf file:
options tulip irq=3
alias tulip tulip2
options tulip2 irq=4 io=0x308
Other functionality offered by 'classic' modprobe is not available in this implementation.
If module options are present both in the config file, and on the command line, then the options from the command line will be passed to the module _after_ the options from the config file. That way, you can have defaults in the config file, and override them for a specific usage from the command line.
Example:
(with the above /etc/modules.conf):
$ modprobe tulip
will load the module 'tulip' with default option 'irq=3'
$ modprobe tulip irq=5
will load the module 'tulip' with option 'irq=5', thus overriding the default
$ modprobe tulip2
will load the module 'tulip' with default options 'irq=4 io=0x308',
which are the default for alias 'tulip2'
$ modprobe tulip2 irq=8
will load the module 'tulip' with default options 'irq=4 io=0x308 irq=8',
which are the default for alias 'tulip2' overridden by the option 'irq=8'
from the command line
$ modprobe tulip2 irq=2 io=0x210
will load the module 'tulip' with default options 'irq=4 io=0x308 irq=4 io=0x210',
which are the default for alias 'tulip2' overridden by the options 'irq=2 io=0x210'
from the command line
more
more [FILE ...]
View FILE or standard input one screenful at a time
Example:
$ dmesg | more
mount
mount [flags] DEVICE NODE [-o options,more-options]
Mount a filesystem. Filesystem autodetection requires /proc be mounted.
Options:
-a Mount all filesystems in fstab
-f "Fake" Add entry to mount table but don't mount it
-n Don't write a mount table entry
-o option One of many filesystem options, listed below
-r Mount the filesystem read-only
-t fs-type Filesystem type
-w Mount for reading and writing (default)
Options for use with the ``-o'' flag:
loop Ignored (loop devices are autodetected)
[a]sync Writes are asynchronous / synchronous
[no]atime Disable / enable updates to inode access times
[no]diratime Disable / enable atime updates to directories
[no]dev Allow use of special device files / disallow them
[no]exec Allow use of executable files / disallow them
[no]suid Allow set-user-id-root programs / disallow them
[r]shared Convert [recursively] to a shared subtree
[r]slave Convert [recursively] to a slave subtree
[r]private Convert [recursively] to a private subtree
[un]bindable Make mount point [un]able to be bind mounted
bind Bind a directory to an additional location
move Relocate an existing mount point
remount Remount a 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 filesystems
Returns 0 for success, number of failed mounts for -a, or errno for one mount.
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
$ mount cd_image.iso mydir
mountpoint
mountpoint [-q]
mountpoint checks if the directory is a mountpoint
Options:
-q Quiet
-d Print major/minor device number of the filesystem
-x Print major/minor device number of the blockdevice
Example:
$ mountpoint /proc
/proc is not a mountpoint
$ mountpoint /sys
/sys is a mountpoint
mt
mt [-f device] opcode value
Control magnetic tape drive operation
Available Opcodes:
bsf bsfm bsr bss datacompression drvbuffer eof eom erase fsf fsfm fsr fss load lock mkpart nop offline ras1 ras2 ras3 reset retension rewind rewoffline seek setblk setdensity setpart tell unload unlock weof wset
mv
mv [OPTION]... SOURCE DEST or: mv [OPTION]... SOURCE... DIRECTORY
Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY
Options:
-f Don't prompt before overwriting
-i Interactive, prompt before overwrite
Example:
$ mv /tmp/foo /bin/bar
nameif
nameif [-s] [-c FILE] [{IFNAME MACADDR}]
Rename network interface while it in the down state
Options:
-c FILE Use configuration file (default is /etc/mactab)
-s Use syslog (LOCAL0 facility)
IFNAME MACADDR new_interface_name interface_mac_address
Example:
$ nameif -s dmz0 00:A0:C9:8C:F6:3F
or
$ nameif -c /etc/my_mactab_file
nc
nc [-options] hostname port - connect nc [-options] -l -p port [hostname] [port] - listen
-l Listen mode, for inbound connects
B Do not do DNS resolution
B addr Local address
B port Local port
B UDP mode
B Verbose (cumulative: B)
B secs Timeout for connects and final net reads
B sec Delay interval for lines sent" /* ", ports scanned" */
B file Hex dump of traffic
B Zero-I/O mode (scanning)
B prog [args] Program to exec after connect (must be last)/* "
B Randomize local and remote ports" */
To use netcat as a terminal emulator on a serial port:
$ stty 115200 -F /dev/ttyS0 $ stty raw -echo -ctlecho && nc -f /dev/ttyS0
Example:
$ nc 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
netstat
netstat [-laentuwxrW]
Display networking information
Options:
-l Display listening server sockets
-a Display all sockets (default: connected)
-e Display other/more information
-n Don't resolve names
-t Tcp sockets
-u Udp sockets
-w Raw sockets
-x Unix sockets
-r Display routing table
-W Display with no column truncation
nice
nice [-n ADJUST] [COMMAND [ARG] ...]
Run a program with modified scheduling priority
Options:
-n ADJUST Adjust the scheduling priority by ADJUST
nmeter
nmeter format_string
Monitor system in real time
Format specifiers:
%Nc or %[cN]
Monitor CPU. N - bar size, default 10
(displays: S:system U:user N:niced D:iowait I:irq i:softirq)
%[niface] Monitor network interface 'iface'
%m Monitor allocated memory
%[mf] Monitor free memory
%[mt] Monitor total memory
%s Monitor allocated swap
%f Monitor number of used file descriptors
%Ni Monitor total/specific IRQ rate
%x Monitor context switch rate
%p Monitor forks
%[pn] Monitor # of processes
%b Monitor block io
%Nt Show time (with N decimal points)
%Nd Milliseconds between updates (default=1000)
%r Print instead of at EOL
Example:
nmeter '%250d%t %20c int %i bio %b mem %m forks%p'
nohup
nohup COMMAND [ARGS]
Run a command immune to hangups, with output to a non-tty
Example:
$ nohup make &
nslookup
nslookup [HOST] [SERVER]
Query the nameserver for the IP address of the given HOST optionally using a specified DNS server
Example:
$ nslookup localhost
Server: default
Address: default
Name: debian
Address: 127.0.0.1
od
od [-aBbcDdeFfHhIiLlOovXx] [FILE]
Write an unambiguous representation, octal bytes by default, of FILE to standard output. With no FILE, or when FILE is -, read standard input.
openvt
openvt VTNUM COMMAND [ARGS...]
Start a command on a new virtual terminal
Example:
openvt 2 /bin/ash
passwd
passwd [OPTION] [name]
Change a user password. If no name is specified, changes the password for the current user.
Options:
-a Define which algorithm shall be used for the password
(choices: des, md5)
" /* ", sha1)" */ B Delete the password for the specified user account
-l Locks (disables) the specified user account
-u Unlocks (re-enables) the specified user account
patch
patch [-p num] [-i diff]
-p NUM Strip NUM leading components from file names
-i DIFF Read DIFF instead of stdin
Example:
$ patch -p1
pgrep
pgrep [-flnovx] pattern
Display process(es) selected by regex pattern
Options:
-l Show command name too
-f Match against entire command line
-n Signal the newest process only
-o Signal the oldest process only
-v Negate the matching
-x Match whole name (not substring)
pidof
pidof process-name [OPTION] [process-name ...]
List the PIDs of all processes with names that match the names on the command line
USAGE_PIDOF
-s Display only a single PID
-o PID Omit given pid
Use %PPID to omit the parent pid of pidof itself
Example:
$ pidof init
1
$ pidof /bin/sh
20351 5973 5950
$ pidof /bin/sh -o %PPID
20351 5950
ping
ping [OPTION]... host
Send ICMP ECHO_REQUEST packets to network hosts
Options:
-4, -6 Force IPv4 or IPv6 hostname resolution
-c CNT Send only CNT pings
-s SIZE Send SIZE data bytes in packets (default=56)
-I iface/IP Use interface or IP address as source
-q Quiet, 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
ping6
ping6 [OPTION]... host
Send ICMP ECHO_REQUEST packets to network hosts
Options:
-c CNT Send only CNT pings
-s SIZE Send SIZE data bytes in packets (default=56)
-I iface/IP Use interface or IP address as source
-q Quiet, only displays output at start
and when finished
Example:
$ ping6 ip6-localhost
PING ip6-localhost (::1): 56 data bytes
64 bytes from ::1: icmp6_seq=0 ttl=64 time=20.1 ms
--- ip6-localhost ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 20.1/20.1/20.1 ms
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] | [-fnovx] [-signal] pattern
Send a signal to process(es) selected by regex pattern
Options:
-l List all signals
-f Match against entire command line
-n Signal the newest process only
-o Signal the oldest process only
-v Negate the matching
-x Match whole name (not substring)
poweroff
poweroff [-d delay] [-n] [-f]
Halt and shut off power
Options:
-d Delay interval for halting
-n No call to sync()
-f Force power off (don't go through init)
printenv
printenv [VARIABLES...]
Print all or part of environment. If no environment VARIABLE specified, print them all.
printf
printf FORMAT [ARGUMENT...]
Format and print ARGUMENT(s) according to FORMAT, where FORMAT controls the output exactly as in C printf
Example:
$ printf "Val=%d\n" 5
Val=5
ps
ps
Report process status
USAGE_PS
-Z Show SE Linux context
w Wide output
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
pscan
pscan [-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT] HOST
Scan a host, print all open ports
Options:
-p Scan from this port (default 1)
-P Scan up to this port (default 1024)
-t Timeout (default 5000 ms)
-T Minimum rtt (default 5 ms, increase for congested hosts)
pwd
pwd
Print the full filename of the current working directory
Example:
$ pwd
/root
raidautorun
raidautorun DEVICE
Tell the kernel to automatically search and start RAID arrays
Example:
$ raidautorun /dev/md0
rdate
rdate [-sp] HOST
Get and possibly set the system date and time from a remote HOST
Options:
-s Set the system date and time (default)
-p Print the date and time
readahead
readahead [FILE]...
Preload FILE(s) in RAM cache so that subsequent reads for thosefiles do not block on disk I/O
readlink
readlink [-f] FILE
Display the value of a symlink
Options:
-f Canonicalize by following all symlinks
readprofile
readprofile [OPTIONS]...
Options:
-m mapfile (Default: /boot/System.map)
-p profile (Default: /proc/profile)
-M mult Set the profiling multiplier to mult
-i Print only info about the sampling step
-v Verbose
-a Print all symbols, even if count is 0
-b Print individual histogram-bin counts
-s Print individual counters within functions
-r Reset all the counters (root only)
-n Disable byte order auto-detection
realpath
realpath pathname ...
Return the absolute pathnames of given argument
reboot
reboot [-d delay] [-n] [-f]
Reboot the system
Options:
-d Delay interval for rebooting
-n No call to sync()
-f Force reboot (don't go through init)
renice
renice {{-n INCREMENT} | PRIORITY} [[-p | -g | -u] ID ...]
Change priority of running processes
Options:
-n Adjusts current nice value (smaller is faster)
-p Process id(s) (default)
-g Process group id(s)
-u Process user name(s) and/or id(s)
reset
reset
Reset the screen
resize
resize
Resize the screen
restorecon
restorecon [-iFnrRv] [-e excludedir]... [-o filename] [-f filename | pathname]
Reset security contexts of files in pathname
-i Ignore files that do not exist
-f filename File with list of files to process. Use - for stdin
-e directory Directory to exclude
-R,-r Recurse directories
-n Don't change any file labels
-o filename Save list of files with incorrect context
-v Verbose
-vv Show changed labels
-F Force reset of context to match file_context
for customizable files, or the user section,
if it has changed
rm
rm [OPTION]... FILE...
Remove (unlink) the FILE(s). You may use '--' to indicate that all following arguments are non-options.
Options:
-i Always prompt before removing each destination
-f Remove existing destinations, never prompt
-r,-R Remove the contents of directories recursively
Example:
$ rm -rf /tmp/foo
rmdir
rmdir [OPTION]... DIRECTORY...
Remove the DIRECTORY, if it is empty
Example:
# rmdir /tmp/foo
rmmod
rmmod [OPTION]... [MODULE]...
Unload the specified kernel modules from the kernel
Options:
-a Remove all unused modules (recursively)
Example:
$ rmmod tulip
route
route [{add|del|delete}]
Edit the kernel's routing tables
Options:
-n Dont resolve names
-e Display other/more information
-A inet{6} Select address family
rpm
rpm -i -q[ildc]p package.rpm
Manipulate RPM packages
Options:
-i Install package
-q Query package
-p Query uninstalled package
-i Show information
-l List contents
-d List documents
-c List config files
rpm2cpio
rpm2cpio package.rpm
Output a cpio archive of the rpm file
run-parts
run-parts [-t] [-l] [-a ARG] [-u MASK] DIRECTORY
Run a bunch of scripts in a directory
Options:
-t Prints what would be run, but does not actually run anything
-a ARG Pass ARG as an argument for every program invoked
-u MASK Set the umask to MASK before executing every program
-l Prints names of all matching files even when they are not executable
Example:
$ run-parts -a start /etc/init.d
$ run-parts -a stop=now /etc/init.d
Let's assume you have a script foo/dosomething:
#!/bin/sh
for i in $*; do eval $i; done; unset i
case "$1" in
start*) echo starting something;;
stop*) set -x; shutdown -h $stop;;
esac
Running this yields:
$run-parts -a stop=+4m foo/
+ shutdown -h +4m
runcon
runcon [-c] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] COMMAND [args]
runcon CONTEXT COMMAND [args]
runcon [-c] [-u USER] [-r ROLE] [-t TYPE] [-l RANGE] COMMAND [args] runcon CONTEXT COMMAND [args] Run a program in a different security context
CONTEXT Complete security context
-c, --compute Compute process transition context before modifying
-t, --type=TYPE Type (for same role as parent)
-u, --user=USER User identity
-r, --role=ROLE Role
-l, --range=RNG Levelrange
runlevel
runlevel [utmp]
Example:
$ runlevel /var/run/utmp
N 2
runsv
runsv dir
Start and monitor a service and optionally an appendant log service
runsvdir
runsvdir [-P] dir
Start a runsv process for each subdirectory
rx
rx FILE
Receive a file using the xmodem protocol
Example:
$ rx /tmp/foo
sed
sed [-efinr] pattern [files...]
Options:
-e script Add the script to the commands to be executed
-f scriptfile Add script-file contents to the
commands to be executed
-i Edit files in-place
-n Suppress automatic printing of pattern space
-r Use extended regular expression syntax
If no -e or -f is given, the first non-option argument is taken as the sed script to interpret. All remaining arguments are names of input files; if no input files are specified, then the standard input is read. Source files will not be modified unless -i option is given.
Example:
$ echo "foo" | sed -e 's/f[a-zA-Z]o/bar/g'
bar
selinuxenabled
selinuxenabled #define selinuxenabled_full_usage
seq
seq [first [increment]] last
Print numbers from FIRST to LAST, in steps of INCREMENT. FIRST, INCREMENT default to 1
Arguments:
LAST
FIRST LAST
FIRST INCREMENT LAST
setarch
setarch personality program [args ...]
Personality may be:
linux32 Set 32bit uname emulation
linux64 Set 64bit uname emulation
setconsole
setconsole [-r|--reset] [DEVICE]
Redirect system console output to DEVICE (default: /dev/tty)
Options:
-r Reset output to /dev/console
setenforce
setenforce [Enforcing | Permissive | 1 | 0]
setfiles
setfiles [-dnpqsvW] [-e dir]... [-o filename] [-r alt_root_path] [-c policyfile] spec_file pathname
Reset file contexts under pathname according to spec_file
-c file Check the validity of the contexts against the specified binary policy
-d Show which specification matched each file
-l Log changes in file labels to syslog
-n Don't change any file labels
-q Suppress warnings
-r dir Use an altenate root path
-e dir Exclude directory
-F Force reset of context to match file_context for customizable files
-o file Save list of files with incorrect context
-s Take a list of files from standard input (instead of command line)
-v Show changes in file labels, if type or role are changing
-vv Show changes in file labels, if type, role, or user are changing
-W Display warnings about entries that had no matching files
setkeycodes
setkeycodes SCANCODE KEYCODE ...
Set entries into the kernel's scancode-to-keycode map, allowing unusual keyboards to generate usable keycodes.
SCANCODE may be either xx or e0xx (hexadecimal), and KEYCODE is given in decimal
Example:
$ setkeycodes e030 127
setlogcons
setlogcons N
Redirect the kernel output to console N (0 for current)
setsid
setsid program [arg ...]
Run any program in a new session by calling
setsid()
before exec'ing the rest of its arguments. See
setsid(2)
for details.
setuidgid
setuidgid account prog args
Set uid and gid to account's uid and gid, removing all supplementary groups, then run prog
sha1sum
sha1sum [OPTION] [FILEs...] or: sha1sum [OPTION] -c [FILE]
Print or check SHA1 checksums. With no FILE, or when FILE is -, read standard input.
Options:
-c Check SHA1 sums against given list
The following two options are useful only when verifying checksums:
-s Don't output anything, status code shows success
-w Warn about improperly formatted SHA1 checksum lines
slattach
slattach [-cehmLF] [-s speed] [-p protocol] DEVICEs
Attach network interface(s) to serial line(s)
Options:
-p Set protocol (slip, cslip, slip6, clisp6 or adaptive)
-s Set line speed
-e Exit after initializing device
-h Exit when the carrier is lost
-c Execute a command when the line is hung up
-m Do NOT initialize the line in raw 8 bits 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
Example:
$ sleep 2
[2 second delay results]
$ sleep 1d 3h 22m 8s
[98528 second delay results]
softlimit
softlimit [-a allbytes] [-c corebytes] [-d databytes] [-f filebytes] [-l lockbytes] [-m membytes] [-o openfiles] [-p processes] [-r residentbytes] [-s stackbytes] [-t cpusecs] prog args
Set soft resource limits, then run prog
Options:
-m n Same as -d n -s n -l n -a n
-d n Limit the data segment per process to n bytes
-s n Limit the stack segment per process to n bytes
-l n Limit the locked physical pages per process to n bytes
-a n Limit the total of all segments per process to n bytes
-o n Limit the number of open file descriptors per process to n
-p n Limit the number of processes per uid to n
Options controlling file sizes:
-f n Limit output file sizes to n bytes
-c n Limit core file sizes to n bytes
Efficiency opts:
-r n Limit the resident set size to n bytes. This limit is not
enforced unless physical memory is full
-t n Limit the CPU time to n seconds. This limit is not enforced
except that the process receives a SIGXCPU signal after n seconds
Some options may have no effect on some operating systems n may be =, indicating that soft limit should be set equal to hard limit
sort
sort [-nrugMcszbdfimSTokt] [-o outfile] [-k start[.offset][opts][,end[.offset][opts]] [-t char] [FILE]...
Sort lines of text in the specified files
Options:
-b Ignore leading blanks
-c Check whether input is sorted
-d Dictionary order (blank or alphanumeric only)
-f Ignore case
-g General numerical sort
-i Ignore unprintable characters
-k Sort key
-M Sort month
-n Sort numbers
-o Output to file
-k Sort by key
-t Use key separator other than whitespace
-r Reverse sort order
-s Stable (don't sort ties alphabetically)
-u Suppress duplicate lines
-z Input terminated by nulls, not newlines
-mST Ignored for GNU compatibility
Example:
$ echo -e "e\nf\nb\nd\nc\na" | sort
a
b
c
d
e
f
$ echo -e "c 3\nb 2\nd 2" | $SORT -k 2,2n -k 1,1r
d 2
b 2
c 3
split
split [OPTION] [INPUT [PREFIX]]
Options:
-b n[k|m] Split by bytes
-l n Split by lines
-a n Use n letters as suffix
Example:
$ split TODO foo
$ cat TODO | split -a 2 -l 2 TODO_
start-stop-daemon
start-stop-daemon [OPTIONS] [--start|--stop] ... [-- arguments...]
Start and stop services
Options:
-S|--start Start
-K|--stop Stop
-a|--startas pathname Starts process specified by pathname
-b|--background Put process into background
-u|--user username|uid Stop this user's processes
-x|--exec executable Program to either start or check
-m|--make-pidfile Create the -p file and enter pid in it
-n|--name process-name Stop processes with this name
-p|--pidfile pid-file Save or load pid using a pid-file
-q|--quiet Quiet
-o|--oknodo Exit status 0 if nothing done
-v|--verbose Verbose
-N|--nicelevel N Add N to process's nice level
-s|--signal signal Signal to send (default TERM)
-c|--chuid user[:[group]] Change to specified user/group
stat
stat [OPTION] FILE...
Display file (default) or filesystem status
Options:
-c fmt Use the specified format
-f Display filesystem status
-L,-l Dereference links
-t Display info in terse form
-Z Print security context
Valid format sequences for files:
%a Access rights in octal
%A Access rights in human readable form
%b Number of blocks allocated (see %B)
%B The size in bytes of each block reported by %b
%d Device number in decimal
%D Device number in hex
%f Raw mode in hex
%F File type
%g Group ID of owner
%G Group name of owner
%h Number of hard links
%i Inode number
%n File name
%N Quoted file name with dereference if symlink
%o I/O block size
%s Total size, in bytes
%t Major device type in hex
%T Minor device type in hex
%u User ID of owner
%U User name of owner
%x Time of last access
%X Time of last access as seconds since Epoch
%y Time of last modification
%Y Time of last modification as seconds since Epoch
%z Time of last change
%Z Time of last change as seconds since Epoch
Valid format sequences for file systems:
%a Free blocks available to non-superuser
%b Total data blocks in file system
%c Total file nodes in file system
%d Free file nodes in file system
%f Free blocks in file system
%C Security context in SELinux
%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 [-afo] [-n length] [file ...]
Display printable strings in a binary file
Options:
-a Scan the whole files (this is the default)
-f Precede each string with the name of the file where it was found
-n N Specifies that at least N characters forms a sequence (default 4)
-o Each string is preceded by its decimal offset in the file
stty
stty [-a|g] [-F DEVICE] [SETTING]...
Without arguments, prints baud rate, line discipline, and deviations from stty sane
Options:
-F DEVICE Open device instead of stdin
-a Print all current settings in human-readable form
-g Print in stty-readable form
[SETTING] See manpage
su
su [OPTION]... [-] [username]
Change user id or become root
Options:
-p, -m Preserve environment
-c Command to pass to 'sh -c'
-s Shell to use instead of default shell
sulogin
sulogin [OPTION]... [tty-device]
Single user login
Options:
-t Timeout
sum
sum [rs] [files...]
Checksum and count the blocks in a file
Options:
-r Use BSD sum algorithm (1K blocks)
-s Use System V sum algorithm (512byte blocks)
sv
sv [-v] [-w sec] command service...
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, do not 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
svlogd
svlogd [-ttv] [-r c] [-R abc] [-l len] [-b buflen] dir...
Continuously read log data from standard input, optionally filter log messages, and write the data to one or more automatically rotated logs
swapoff
swapoff [-a] [DEVICE]
Stop swapping virtual memory pages on DEVICE
Options:
-a Stop swapping on all swap devices
swapon
swapon [-a] [DEVICE]
Start swapping virtual memory pages on DEVICE
Options:
-a Start swapping on all swap devices
switch_root
switch_root [-c /dev/console] NEW_ROOT NEW_INIT [ARGUMENTS_TO_INIT]
Use from PID 1 under initramfs to free initramfs, chroot to NEW_ROOT, and exec NEW_INIT
Options:
-c Redirect console to device on new root
sync
sync
Write all buffered filesystem blocks to disk
sysctl
sysctl [OPTIONS]... [VALUE]...
Configure kernel parameters at runtime
Options:
-n Use this option to disable printing of the key name when printing values
-w Use this option when you want to change a sysctl setting
-p Load in sysctl settings from the file specified or /etc/sysctl.conf if none given
-a Display all values currently available
-A Display all values currently available in table form
Example:
sysctl [-n] variable ...
sysctl [-n] -w variable=value ...
sysctl [-n] -a
sysctl [-n] -p file (default /etc/sysctl.conf)
sysctl [-n] -A
syslogd
syslogd [OPTION]...
System logging utility. Note that this version of syslogd ignores /etc/syslog.conf.
Options:
-n Run in foreground
-O FILE Log to given file (default=/var/log/messages)
-l n Set local log level
-S Smaller logging output
-s SIZE Max size (KB) before rotate (default=200KB, 0=off)
-b NUM Number of rotated logs to keep (default=1, max=99, 0=purge)
-R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP)
-L Log locally and via network (default is network only if -R)
-C[size(KiB)] Log to shared mem buffer (read it using logread)
Example:
$ syslogd -R masterlog:514
$ syslogd -R 192.168.1.1:601
tail
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:
-c N[kbm] Output the last N bytes
-n N[kbm] Print last N lines instead of last 10
-f Output data as the file grows
-q Never output headers giving file names
-s SEC Wait SEC seconds between reads with -f
-v Always output headers giving file names
If the first character of N (bytes or lines) is a '+', output begins with the Nth item from the start of each file, otherwise, print the last N items in the file. N bytes may be suffixed by k (x1024), b (x512), or m (1024^2).
Example:
$ tail -n 1 /etc/resolv.conf
nameserver 10.0.0.1
tar
tar -[czjaZxtvO] [-X FILE] [-f TARFILE] [-C DIR] [FILE(s)] ...
Create, extract, or list files from a tar file
Options:
c Create
x Extract
t List
Archive format selection:
z Filter the archive through gzip
j Filter the archive through bzip2
a Filter the archive through lzma
Z Filter the archive through compress
File selection:
f Name of TARFILE or "-" for stdin
O Extract to stdout
exclude File to exclude
X File with names to exclude
C Change to directory DIR before operation
v Verbose
Example:
$ zcat /tmp/tarball.tar.gz | tar -xf -
$ tar -cf /tmp/tarball.tar /usr/local
taskset
taskset [OPTIONS] [mask] [pid | command [arg]...]
Set or get CPU affinity
Options:
-p Operate on an existing PID
Example:
$ taskset 0x7 ./dgemm_test&
$ taskset -p 0x1 $!
pid 4790's current affinity mask: 7
pid 4790's new affinity mask: 1
$ taskset 0x7 /bin/sh -c './taskset -p 0x1 $$'
pid 6671's current affinity mask: 1
pid 6671's new affinity mask: 1
$ taskset -p 1
pid 1's current affinity mask: 3
tcpsvd
tcpsvd [-hEv] [-c n] [-C n:msg] [-b n] [-u user] [-l name] ip port prog...
Creates TCP socket, binds it to ip:port and listens on it for incoming connections. For each connection it runs prog.
ip
IP to listen on. '0' = all
port
Port to listen on
prog [arg]
Program to run
-l name
Local hostname (else looks up local hostname in DNS)
-u user[:group]
Change to user/group after bind
-c n
Handle up to n connections simultaneously
-b n
Allow a backlog of approximately n TCP SYNs
-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
B Look up peer's hostname
B Do not set up environment variables
B Verbose
tee
tee [OPTION]... [FILE]...
Copy standard input to each FILE, and also to standard output
Options:
-a Append to the given FILEs, do not overwrite
-i Ignore interrupt signals (SIGINT)
Example:
$ echo "Hello" | tee /tmp/foo
$ cat /tmp/foo
Hello
telnet
telnet HOST [PORT]
Connect to remote telnet server
telnetd
telnetd [OPTION]
Handle incoming telnet connections
Options:
-l LOGIN Exec LOGIN on connect
-f issue_file Display issue_file instead of /etc/issue
-p PORT Port to listen to
-b ADDR Address to bind to
-F Run in foreground
-i Run as inetd subservice
test
test EXPRESSION or [ EXPRESSION ]
Check 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
tftp
tftp [OPTION]... HOST [PORT]
Transfer a file from/to tftp server using ``octet'' mode
Options:
-l FILE Local FILE
-r FILE Remote FILE
-g Get file
-p Put file
-b SIZE Transfer blocks of SIZE octets
time
time [OPTION]... COMMAND [ARGS...]
Run the program COMMAND with arguments ARGS. When COMMAND finishes, COMMAND's resource usage information is displayed.
Options:
-v Verbose
top
top [-b] [-n count] [-d seconds]
Provide a view of process activity in real time. Read the status of all processes from /proc each and show the status for however many processes will fit on the screen.
touch
touch [-c] FILE [FILE ...]
Update the last-modified date on the given FILE
Options:
-c Do not create any files
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
tr
tr [-cds] STRING1 [STRING2]
Translate, squeeze, and/or delete characters from standard input, writing to standard output
Options:
-c Take complement of STRING1
-d Delete input characters coded STRING1
-s Squeeze multiple output characters of STRING2 into one character
Example:
$ echo "gdkkn vnqkc" | tr [a-y] [b-z]
hello world
traceroute
traceroute [-FIldnrv] [-f 1st_ttl] [-m max_ttl] [-p port#] [-q nqueries]
[-s src_addr] [-t tos] [-w wait] [-g gateway] [-i iface]
[-z pausemsecs] host [data size]
Trace the route to ``host
Options:
-F Set the don't fragment bit
-I Use ICMP ECHO instead of UDP datagrams
-l Display the ttl value of the returned packet
-d Set SO_DEBUG options to socket
-n Print hop addresses numerically rather than symbolically
-r Bypass the normal routing tables and send directly to a host
-v Verbose
-m max_ttl Max time-to-live (max number of hops)
-p port# Base UDP port number used in probes
(default is 33434)
-q nqueries Number of probes per 'ttl' (default 3)
-s src_addr IP address to use as the source address
-t tos Type-of-service in probe packets (default 0)
-w wait Time in seconds to wait for a response
(default 3 sec)
-g Loose source route gateway (8 max)
true
true
Return an exit code of TRUE (0)
Example:
$ true
$ echo $?
0
tty
tty
Print file name of standard input's terminal
Options:
-s Print nothing, only return exit status
Example:
$ tty
/dev/tty2
ttysize
ttysize [w] [h]
Print dimension(s) of standard input's terminal, on error return 80x25
tune2fs
tune2fs [-c max-mounts-count] [-e errors-behavior] [-g group] [-i interval[d|m|w]] [-j] [-J journal-options] [-l] [-s sparse-flag] [-m reserved-blocks-percent] [-o [^]mount-options[,...]] [-r reserved-blocks-count] [-u user] [-C mount-count] [-L volume-label] [-M last-mounted-dir] [-O [^]feature[,...]] [-T last-check-time] [-U UUID] device
Adjust filesystem options on ext[23] filesystems
udhcpc
udhcpc [-Cfbnqtv] [-c CID] [-V VCLS] [-H HOSTNAME] [-i INTERFACE]
[-p pidfile] [-r IP] [-s script]
-V,--vendorclass=CLASSID Set vendor class identifier
-i,--interface=INTERFACE Interface to use (default: eth0)
-H,-h,--hostname=HOSTNAME Client hostname
-c,--clientid=CLIENTID Set client identifier
-C,--clientid-none Suppress default client identifier
-p,--pidfile=file Store process ID of daemon in file
-r,--request=IP IP address to request
-s,--script=file Run file at dhcp events (default: /usr/share/udhcpc/default.script)
-t,--retries=N Send up to N request packets
-f,--foreground Run in foreground
-b,--background Background if lease cannot be immediately negotiated
-S,--syslog Log to syslog too
-n,--now Exit with failure if lease cannot be immediately negotiated
-q,--quit Quit after obtaining lease
-R,--release Release IP on quit
-v,--version Display version
udhcpd
udhcpd [-fS] [configfile]
DHCP server
-f Run in foreground
-S Log to syslog too
udpsvd
udpsvd [-hEv] [-c n] [-u user] [-l name] ip port prog
Creates UDP socket, binds it to ip:port and listens on it for incoming packets. For each packet it runs prog (redirecting all further packets with same peer ip:port to it).
ip
IP to listen on. '0' = all
port
Port to listen on
prog [arg]
Program to run
-l name
Local hostname (else looks up local hostname in DNS)
-u user[:group]
Change to user/group after bind
-c n
Handle up to n connections simultaneously
-h
Look up peer's hostname
-E
Do not set up environment variables
-v
Verbose
umount
umount [flags] FILESYSTEM|DIRECTORY
Unmount file systems
Options:
-a Unmount all file systems in /etc/mtab
-n Don't erase /etc/mtab entries
-r Try to remount devices as read-only if mount is busy
-l Lazy umount (detach filesystem)
-f Force umount (i.e., unreachable NFS server)
-D Do not free loop device (if a loop device has been used)
Example:
$ umount /dev/hdc1
uname
uname [OPTION]...
Print certain system information. With no OPTION, same as -s.
Options:
-a Print all information
-m The machine (hardware) type
-n Print machine's hostname
-r Print OS release
-s Print OS name
-p Print host processor type
-v Print OS version
Example:
$ uname -a
Linux debian 2.4.23 #2 Tue Dec 23 17:09:10 MST 2003 i686 GNU/Linux
uncompress
uncompress [-c] [-f] [name...]
Uncompress .Z file
Options:
-c Extract to stdout
-f Force overwrite an existing file
unexpand
unexpand [-f][-a][-t NUM] [FILE|-]
Convert spaces to tabs, writing to standard output.
Options:
-a,--all Convert all blanks
-f,--first-only Convert only leading sequences of blanks
-t,--tabs=N Tabstops every N chars
uniq
uniq [-fscdu]... [INPUT [OUTPUT]]
Discard all but one of successive identical lines from INPUT (or standard input), writing to OUTPUT (or standard output)
Options:
-c Prefix lines by the number of occurrences
-d Only print duplicate lines
-u Only print unique lines
-f N Skip the first N fields
-s N Skip the first N chars (after any skipped fields)
Example:
$ echo -e "a\na\nb\nc\nc\na" | sort | uniq
a
b
c
unix2dos
unix2dos [option] [FILE]
Convert FILE from unix format to dos format. When no option is given, the input is converted to the opposite output format. When no file is given, use stdin/stdout.
Options:
-u Output will be in UNIX format
-d Output will be in DOS format
unlzma
unlzma [OPTION]... [FILE]
Uncompress FILE (or standard input if FILE is '-' or omitted)
Options:
-c Write output to standard output
-f Force
unzip
unzip [-opts[modifiers]] file[.zip] [-x xlist] [-d exdir]
Extract files from ZIP archives
Options:
-l List archive contents (with -q for short form)
-n Never overwrite existing files (default)
-o Overwrite files without prompting
-p Send output to stdout
-q Quiet
-x Exclude these files
-d Extract files into this directory
uptime
uptime
Display the time since the last boot
Example:
$ uptime
1:55pm up 2:30, load average: 0.09, 0.04, 0.00
usleep
usleep N
Pause for N microseconds
Example:
$ usleep 1000000
[pauses for 1 second]
uudecode
uudecode [-o outfile] [infile]
Uudecode a file NB: finds outfile name in uuencoded source unless -o is given
Example:
$ uudecode -o busybox busybox.uu
$ ls -l busybox
-rwxr-xr-x 1 ams ams 245264 Jun 7 21:35 busybox
uuencode
uuencode [-m] [infile] stored_filename
Uuencode a file to stdout
Options:
-m Use base64 encoding per RFC1521
Example:
$ uuencode busybox busybox
begin 755 busybox
$ uudecode busybox busybox > busybox.uu
$
vconfig
vconfig COMMAND [OPTIONS] ...
Create and remove virtual ethernet devices
Options:
add [interface-name] [vlan_id]
rem [vlan-name]
set_flag [interface-name] [flag-num] [0 | 1]
set_egress_map [vlan-name] [skb_priority] [vlan_qos]
set_ingress_map [vlan-name] [skb_priority] [vlan_qos]
set_name_type [name-type]
vi
vi [OPTION] [FILE]...
Edit FILE
Options:
-R Read-only - do not write to the file
vlock
vlock [OPTIONS]
Lock a virtual terminal. A password is required to unlock.
Options:
-a Lock all VTs
watch
watch [-n seconds] [-t] COMMAND...
Execute a program periodically
Options:
-n Loop period in seconds (default 2)
-t Don't print header
Example:
$ watch date
Mon Dec 17 10:31:40 GMT 2000
Mon Dec 17 10:31:42 GMT 2000
Mon Dec 17 10:31:44 GMT 2000
watchdog
watchdog [-t N[ms]] [-F] DEV
Periodically write to watchdog device DEV
Options:
-t N Timer period (default 30)
-F Run in foreground
Use -t 500ms to specify period in milliseconds
wc
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
wget
wget [-c|--continue] [-s|--spider] [-q|--quiet] [-O|--output-document file]
[--header 'header: value'] [-Y|--proxy on/off] [-P DIR]
[-U|--user-agent agent] url
Retrieve files via HTTP or FTP
Options:
-s Spider mode - only check file existence
-c Continue retrieval of aborted transfer
-q Quiet
-P Set directory prefix to DIR
-O Save to filename ('-' for stdout)
-U Adjust 'User-Agent' field
-Y Use proxy ('on' or 'off')
which
which [COMMAND ...]
Locate a COMMAND
Example:
$ which login
/bin/login
who
who
Print the current user names and related information
whoami
whoami
Print the user name associated with the current effective user id
xargs
xargs [OPTIONS] [COMMAND] [ARGS...]
Execute COMMAND on every item given by standard input
Options:
-p Prompt the user about whether to run each command
-r Do not run command for empty read lines
-x Exit if the size is exceeded
-0 Input filenames are terminated by a null character
-t Print the command line on stderr before executing it
Example:
$ ls | xargs gzip
$ find . -name '*.c' -print | xargs rm
yes
yes [OPTION]... [STRING]...
Repeatedly output a line with all specified STRING(s), or 'y'
zcat
zcat FILE
Uncompress to stdout
zcip
zcip [OPTIONS] ifname script
Manage a ZeroConf IPv4 link-local address
Options:
-f Run in foreground
-q Quit after address (no daemon)
-r 169.254.x.x Request this address first
-v Verbose
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.
本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u2/70592/showart_723794.html |
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发表于 2008-06-02 13:25