Bourne/Bash/Korn Commands

This is post 7 of 19 in the series “[ Shell Scripting ]”

This series introduces students to Linux and Unix bash shell scripting.

A Short Catalog of Bourne/bash/Korn Shell Commands

Command	OS	Description	Example	Explanation
alias		Creates an “alias” for a command and set of options	alias rm=”rm -i”	Set in .bashrc, forces deletes into interactive mode
cancel -a printer		Removes all print requests from the current user on the specified printer	cancel -a bobsprt	Removes all the requests from the current user to the printer named bobsprt
cancel request_id		Stops print jobs or removes them from the queue (request_ids are obtained using lpstat)	cancel 5438	Stops the print job with the id 5438 whether it is printing or if it is sitting in the queue
cancel -u login_id		Removes any print requests queued belonging to the user	cancel -u bob	Cancels all queued print requests for user bob
cat file		Prints a file to the screen (all at once). Use more or less to see a page at a time.	cat /etc/passwd	Prints the password file to the screen.
cat file1 file2 file3		Think “concatenate” – Shows the three files in consecutive order as one document (can be used to combine files)	cat cheese milk	This prints the cheese file to the screen first and immediately follows it with the milk file.
cd directory		Changes your current directory to the directory specified	cd bin	Changes directory to the bin directory
		For example, if current directory=/home/users/bob/bin and you execute cd .. the new directory will be = /home/users/bob	cd ..	Moves you to the directory that contains the directory you are currently in
		or executing cd ../.. results in the new directory= /home/users.	cd ../..
			cd –	Moves you to the directory you just came from
			cd ~	Moves you to your home directory (the directory you start from initially)
			cd	Moves you to your home directory (the directory you start from initially)
chexp # filename		Keeps the file(s) from expiring (being erased) on the target computer for # days	chexp 365 nr*	Keeps the target computer from deleting all files starting with nr for 1 year (365 days)
			chexp 4095 nr*	Makes all files whose name starts with nr never expire or be deleted (infinite)
clear		Clears the window and the line buffer	clear	None
compress filename		Compresses the file to save disk space.	none	None
cp -f name target		Forces existing pathnames to be destroyed before copying the file	none	No example or description needed
		Copies a file (file1) and names the copy the new name (newname)	cp old new	Makes a copy of the file/directory named old and names the copy new, all within the current directory
				NOTE: If you copy a file to a newfile name and newfile already exists, the newfile contents will be overwritten.
			cp file dir2/	Places a copy of file in dir2/ and it retains its original name
			cp ../dir1/* .	Copies everything from the dir1 directory located just below where you currently are and places the copy “here” ( . ) in your current directory
				NOTE: When clicking in the scroll bar, the left button scrolls down, the right scrolls up, and the middle snaps the scroll bar to the mouse position for dragging up and down.
cp -p name target		Preserves all permissions in the original to the target	cp -p execut1 execut2	Copies execut1 executable file and calls the copy execut2, which also has executable permissions
cp -R directory target		Copies a directory and names the copy the new name (target)	cp -R old/ junk/	Makes a copy of the directory named old and names the directory copy junk
cut		cuts characters or fields from a file	cut -f1 myfile	Returns the first field (tab-delimited) of each line of myfile
			cut -c1 myfile cut -c1-8 myfile	Returns the first character, or chars 1-8, of myfile
			cut -f2 myfile	Returns the second field of each (tab-delimited) line of myfile
			cut -d: -f1 myfile	Returns the first field of a colon-delimited myfile (any delimiter may be specified)
date		Writes the current date to the screen	date	Mon Nov 20 18:25:37 EST 2000
df system		Reports the number of free disk blocks	df ~ , df $HOME	Both commands will print the total kb space, kb used, kb available, and %used on the home system (your system).
dir		Same as ls -la ; adopted from DOS!	dir
du		Disk usage:	du -sc	Dumps information about file system size, i.e. disk usage
echo		Prints text to the terminal	echo “Hello” echo *	Prints “Hello” Prints a directory listing (surprise) See the excellent SS64.com page.
ed		The line editor utility
emacs filename		Another text editor	none	None
eval `resize`		Tells the target computer that you’ve resized the window during telnet	none	None
fdisk, sfdisk, cfdisk		Utility for partitioning disks	fdisk	Opens a user interface to manage disk partitions
find		Finds files on disk	find / -name file_name	Specify a location to start in the first argument. Use -name to search for a file name.
finger		Displays info about all system users	finger
finger username		Displays info about username	finger glenn
fsck		Performs a file system check (similar to checkdisk)
grep		grep is useful when you use it in a \| “pipe”	ps -ef \| grep bob	Finds all processes in full listing and then prints only the ones that match the string bob to the screen
		You can also redirect its output to a file.	grep -i jan b_days>mymonth	Searches the file b_days for case-insensitive matches to jan and places the matching lines into a file called mymonth
grep -c string file		Searches and prints only the number of matches to the screen	grep -c hayes bankletter	Searches the file bankletter for the string hayes and prints the number of matches to the screen
grep -i string file		Searches without regard to letter case	grep -i hi file1	Searches file1 for hi, Hi, hI, and HI and prints all matches to the screen
grep -n string file		Prints to the screen preceded by the line number	grep -n abc alpha	Searches alpha for abc and prints the matches’ lines and line numbers to the screen
grep string file		Searches input file(s) for specified string and prints the line with matches	grep mike letter	Searches for the string mike in the file named letter and prints any line with mike in it to the screen
grep -v string file		All lines that do not match are printed	grep -v lead pencils	Prints all lines in pencils that do not contain the string lead
grep -x string file		Only exact matches are printed	grep -x time meetings	Prints only lines in meetings that match time exactly
head file		Prints the first 10 lines of the file to the screen	head addresses	Prints the first 10 lines of addresses to the screen
		Number of lines can be modified	head -25 addresses	Prints the first 25 lines of addresses to the screen
help		Lists shell commands (not scripts)	help	Prints a listing of built-in shell commands
history		Prints your command history
id		Prints your user id info	id
info		Gives help on built-in shell commands
kill -9 process_id		Destroys the process with the said id	kill -9 6969	PID # 6969 doesn’t have a chance here.
kill process_id		Stops the process with the said id	kill 6969	Kills the process with PID 6969
killall process_name		Kills all processes with the provided name	killall httpd	Kills all httpd processes
lilo		Linux Loader	lilo	reinstalls LILO in the boot sector, after editing lilo.conf
linuxconf		The Linux Configurator	linuxconf
lp (-option) file(s)		Like pr, this prints designated files on the connected printer(s) (options not required and options may be combined).	lp junkfile	Prints the file junkfile to the default printer in default one-sided, single-sided, single-spaced format
lp -ddest file(s)		Prints the file(s) to a specific destination	lp -dbobsq zoom	Sends the file zoom to the bobsq print queue to print
lp -nnumber file(s)		Allows user to designate the number of copies to be printed	lp -n5 crash	Prints five copies of crash in default settings
lp -ooption file(s)			lp -ohalf output	Divides the paper into two halves for printing output
			lp -oquarter output	Prints four pages of output per side of paper
			lp -olandscape output	Prints output in landscape orientation
			lp -oportrait output	Prints output in portrait orientation
		Allows printer-specific options to be used (i.e., double-sided or two pages per side, etc.)	lp -od output	Prints the output file double-sided on the printout
			lp -obold output	Prints output in bold print
lp -ttitle file(s)		Places title on the banner page	lp -tBobs cash	Prints Bobs on the banner page of the file printout named cash
lpconfig -d queue		Makes the said queue the default queue	lpconfig -d vpprnt	Makes vpprnt the default print queue
lpconfig printer_id queue		Configures remote printers to a local print queue	lpconfig prntr1 bobprt	Configures a printer named prntr1 to accept print requests from a local queue named bobprt
lpconfig -r queue		Removes the said queue from the local system	lpconfig -r bobprt	Removes bobprt queue from the local system if the person removing the queue is the owner or “root”
lpstat (-options)		Prints printer status information to screen (options not required)	lpstat	Prints status of all requests made to the default printer by the current server
lpstat -d		Shows the default printer for the lp command	none	None
lpstat -r		Lets you know if the line printer scheduler is running	none	None
lpstat s		Prints the queues and the printers they print to	none	None
lpstat -t		Shows all print status information	none	None
lpstat -u”user1, user2″		Prints the status of requests made by the specified users	lpstat -u”bob”	Prints status of all requests made by the user with the id bob
ls (-option-optional)		Lists all the nonhidden files and directories	ls	Lists all nonhidden files and directories in the current directory
ls (-option-optional)			ls bin	Lists all nonhidden files and directories in the bin directory
ls -a		Lists all files and directories including hidden ones	ls -a	Lists all files and directories, including hidden, in the current directory
			ls -a temp	Lists all files and directories in the temp directory.
ls -al		NOTE: Options can be combined using ls		Lists all files (including hidden (-a)) in long format (-l)
ls -l or ll		Lists all nonhidden files and directories in long format	ls -l	Lists all nonhidden files and directories in the current directory in long format
			ll
			ls -l work	Lists all nonhidden files and directories in the work directory in long format
			ll work
ls -r		Lists all files and directories in reverse alphabetical order	ls -r	Lists all nonhidden files and directories in the current directory in reverse alphabetical order
			ls -r abc	Lists all nonhidden files and directories in the abc directory in reverse alphabetical order
ls -t		Lists all nonhidden files in the order they were last modified	ls -t	Lists all the nonhidden files in the current directory in the order they were last modified from most recent to last
			ls -t work	Lists all the nonhidden files in the work directory in the order they were last modified from most recent to last
make compilecommand		Performs the pre-compile and compile functions	make	Used at several stages of compilation. Used in preparing a custom Linux kernel.
mc
minicom				Opens a graphical utility in a shell, which is used to test PPP connections like modems.
mkdir dirname		Creates a directory	mkdir junk	Makes a directory named junk in your current directory
		You can also designate where the directory is to reside.	mkdir ~/left	Makes a directory in your home directory named left
modprobe		Adds a kernel module while running	modprobe module modprobe -r module modprobe -a modprobe -k	Loads module Removes module Lists all modules Auto-cleans all modules
more input		This prints to screen whatever is input-useful because it only shows one screen at a time.	more groceries	This will list the groceries file to the screen.
		scroll bar continues to the next screen
		return moves one line forward
		Q quits
		G goes to the end
		1G goes to the beginning
		Ctrl u moves up ½ screen
		Ctrl d moves down ½ screen
mount drive		Mount a drive	mount /mnt/cdrom	Mounts the CDrom drive
mouseconfig		Sets up the mouse	mouseconfig
mv initial final		Renames files and directories	mv temp script_1	Renames the file (or directory) temp to the name script_1 in the current directory
		Also moves files to other directories	mv script.exe ~/bin	Moves the script.exe file to the bin directory that is in the home (~) parent directory and it keeps its initial name
		You can do multiple moves.	mv script_1 script.exe ~/bin	Moves both script_1 and script.exe to the bin directory
netcfg		Configure the network; not found on all Linux systems, but common on other Unix like Solaris	netcfg
nislookup		Returns DNS information	nislookup google.com	Returns the IP address if DNS is working
dhclient		DHCP client program
passwd		Change your password	pswd
paste		Paste corresponding lines of files together	paste file1 file2	Outputs line 1 of file1 “pasted” to line 1 of file2, and so forth line by line
pr -h “header” filename		Prints the file with a specified header rather than the filename	pr -h “users” userlist	Prints userlist with users as the header
pr (option) filename		Prints the specified file to the default printer (options are not required but can be combined in any order) Options can be combined using pr	pr userlist	Prints the contents of userlist to the default printer
pr +k filename		Starts printing with page k	pr +5 userlist	Prints the contents of userlist starting with page 5
pr -a filename		Prints in multicolumns across the page (use with -k)	pr -3a userlist1	Prints userlist in three columns across the page
pr -d filename		Prints in double space format	pr -d userlist	Prints userlist with double space format
pr -k filename		Prints in k columns	pr -2 userlist	Prints the contents of userlist in 2 columns
ps		Shows certain information about active processes associated with the current terminal	ps	Shows a listing of process IDs, terminal identifier, cumulative execution time, and command name
ps -e		Shows information about all processes	ps -e	Shows a listing of process IDs, terminal identifiers, cumulative execution time, and command names for all processes
ps -ef		Shows all processes in a full listing	ps -ef	Shows all current processes in full listing
ps -f		Shows a full listing of information about the processes listed	ps -f	Shows UID (user or owner of the process), PID (process ID–use this number to kill it), PPID (process ID of the parent source), C (processor utilization for scheduling), STIME (start time of the process), TTY (controlling terminal for the process), TIME (cumulative time the process has run), and COMMAND (the command that started the process)
ps -u user_id		Shows all processes that are owned by the person with the pertinent user_id	ps -u bob	Shows all the processes that belong to the person with the userid bob
pump	RH7 and older	A BOOTP and DHCP client daemon	pump	Renews DHCP lease
pwd		Prints the current directory to the screen	pwd	May print something like “/home/bob”
qstat		Displays the status of a process that has been submitted the Network Queuing System (basically a batch job)	qstat	Shows the status of the requests submitted by the invoker of the command-this will print request–name, request–id, the owner, relative request priority, and request state (is it running yet?)
			qstat -a	Shows all requests
			qstat -l	Shows requests in long format
			qstat -m	Shows requests in medium-length format
			qstat -u bob	Shows only requests belonging to the user bob
			qstat -x	Queue header is shown in an extended format
read		Captures user input	echo -n “Enter the name of an animal: “ read ANIMAL echo -n “You are a(n) $ANIMAL”
restart			/etc/init.d/nfs restart	Restarts a service, in this cast the nfs
rm -f file1 file2			rm xyz abc	Deletes the files named xyz and abc
			rm *	Deletes everything nonhidden
		Forces deletion without prompt regardless of permissions	rm -f program	Removes the file program without regard to permissions, status, etc.
rm file1 file2 file3		Removes (deletes) file(s) NOTE: Options can be combined using rm	rm xyz	Deletes a file named xyz
rm -fR name, rm -Rf name **dangerous**		This combination will force the removal of any file and any directory including anything inside of it	rm -Rf c_ya	Forces removal without prompts of the c_ya directory and anything inside of it
rm -i file1 file2		Prompts before deletion of files. *****USE -i AT FIRST*****	rm -i *	Prompts at each nonhidden file and lets you decide whether or not to delete it
rm -r directory, rm -R directory		Remove a directory along with anything inside of it	rm -r bin , rm -R bin	Each of these will remove the bin directory and everything inside of it.
rm -Ri directory		Deletes the contents of a directory and the directory if it is empty by prompting the user before each deletion	rm -Ri rusure	Deletes anything in the directory called rusure that you verify at the prompt, and if you remove everything in the directory, you will be prompted whether you want to remove the directory itself or not
rmdir directory		Removes a directory like rm -r does if the directory is empty	rmdir bin	Removes the bin directory if it is empty
rmdir -p directory		Removes a directory and any empty parent directories above it (-pi does the same thing but it prompts before each removal)	rmdir -p /home/bin/dir1	Deletes the dir1 directory; if bin directory is empty, it is deleted, and if home directory is empty it is also deleted
sed		The stream editor	sed ‘s/Unix/UNIX/’ source_file/g	Replaces Unix with UNIX in source_file
sort infile		Sorts the contents of the input file in alphabetical order	sort names	Sorts the contents of names in alphabetical order
tail file		Prints the last 10 lines of the file to the screen	tail test.txt	Prints the last 10 lines of test.txt to the screen
		Number of lines can be modified here, too	tail -32 test.txt	Prints the last 32 lines of test.txt to the screen
test expression		Tests a condition, and returns 0 (success) if it passes, non-0 if it fails	test	See Operators for a fuller listing
		Used in if operations	if test $name = Julio; then
			test string = string
			test string != string	tests inequality
			if test string ; then	tests for the existence of string
			test -n string	string is not null
			test -z string	string is null
			test int1 -eq int2	int1 equals int2
			test int1 -ge int2	int1 greater than or equal to to int2
			test int1 -gt int2	int1 is greater than int2
			test int1 -le int2	int1 is less than or equal to int2
			test int1 -lt int2	int1 is less than int2
			test int1 -ne int2	int1 is not equal to int2
			test -d file	file is a directory
			test -e file	file exists
			test -f file	file is a regular file
			test -r file	file is readable by the process
			test -s file	file has nonzero length
			test -w file	file is writable by the process
			test -x file	file is executable
			test -L file	file is a symbolic link
timeconfig		Configure the time service	timeconfig
touch		Update the last-modified date of the file named	touch myfile	If myfile exists, last-modified date is updated to now; if myfile doesn’t exist, it is created
type		Find out where a bash command is taken from (cf. which); tells if an executable is a binary, script or link	type bash	bash is /bin/bash
type -a		Print all locations of a command	type -a bash
uncompress filename		Expands a compressed file	none
uptime		Displays time the system has been running	uptime
useradd		Add a user to the domain	useradd
users		Lists current users	users	Lists all users on a single line
vi filename		Text editor that exists on every UNIX system in the world	none
vuepad filename		Opens filename for editing/viewing in the vuepad editor	none
which		Prints the locations of shell commands (cf. type)
who		Tells you who is logged onto your server	who -imH	Lists each user on a separate line, along with session information
who am I		Tells you your user information	who am I , whoami
Xconfigurator		An X-Windows configuration tool	Xconfigurator	This opens an interface to configure your video card and monitor.
xterm		Opens a new window (x-terminal) for you to work	xterm	This opens another window like the one you are currently working in.
		Note: The size of the window takes precedence over position, so if you position it too close to the side of the screen, it will position at the edge with the correct size.	xterm -geom 5×5+0+0	The third command will make a 5 by 5 window and position its top left-hand corner at the top left-hand corner of the screen. xterm will not compromise size when positioning.
			xterm -bd huntergreen	The second command sets the window border color to huntergreen.
			xterm -fg red
		Position +0+0 is the top left-hand corner of the screen, and the bottom right is approx. +1200+1000 depending on your resolution.	xterm -geom 10×35+300+500	The second command will open a window 10 pixs wide by 35 pixs tall and position its top left-hand corner 300 pixs from the left edge and 500 pixs down from the top.
xterm -(areas) color		Allows you to modify different colors in your xterm window	xterm -bg white	The first command sets the background color to white.
xterm +option		+option resets the option to default		Options can be combined using xterm
xterm -e program		Executes the listed program in the new xterm window-when the program is finished, the new xterm window goes away	xterm -e myprog.exe	This opens an xterm window and executes the program myprog.exe from that window so that you may still work in your present window.
xterm -fn font		Sets the font in the new xterm window	xterm -fn courr18	Sets the font to courr18 (default is fixed)
xterm -geom xxy+px+py		This option allows you to specify the size x pixels by y pixels and placement position x by position y of the new window when it opens.	xterm -geom 80×80+0+50	The first command will open a window 80 pixels wide by 80 pixels tall and position its top left-hand corner at 0 pixels to the right of the left edge and 50 pixels down from the top of the screen.
xterm -help		Displays the xterm options	xterm -help	Shows the options available
xterm -iconic		Starts the new xterm as an icon (double-click to maximize)	xterm -iconic -title xyz	Opens an xterm in iconic form with the title xyz
xterm -option		-option sets the option		USING XTERM WILL ELIMINATE A LOT OF DESKTOP CLUTTER. I STRONGLY SUGGEST YOU LEARN TO USE IT IN YOUR SCRIPTS.
xterm -sb		Opens an xterm that saves a set number of lines when they go off the top of the page and makes them accessible with a scroll bar	xterm -sb	Puts a scroll bar on the right side of the page for reviewing past lines in the window
xterm -sl number		Specifies the number of lines to be saved once they go off the top of the screen (default is 64)	xterm -sl 1000	The xterm will save 1,000 lines of work once it has moved off the immediate viewing area; it can be accessed using the scroll bar.
xterm -title label		Allows you to label your window’s top title bar	xterm -title SCRIPTS	Opens an xterm window with the title SCRIPTS (default is whatever follows the -e option)