Basic Unix Commands

The UNIX operating systems is a set of programs that act as a link between the computer and user

Command/Syntax	Example	Description
$ users		Check the user name
$ who		Check the user information
$ whoami		Get the user name
$ Finer		Display ,who is on computer in the lap
Directories .[dot]  & ..[dot dot]		Filename .(dot) point out current working directory Filename ..(dot dot) represent one level above the current working directory
$ ls		List out files in current directories
$ ls -l		List all files in the current working directory in long listing format showing permissions, ownership, size, and time and date stamp
$ls -a		List out content folder , including the hidden files Hints: Linux file starting with ‘.’ is hidden
$ pwd		Display the current working directory path
$ ps		Display information about programs that are running currently
$ Date		Display the current day , date time and year
$ uname		Uname – Unix name, displayed details information about OS, kernel and machine name Example : Linux asiat16 2.6.18-308.20.1.el5PAE #1 SMP Tue Nov 6 04:43:35 EST 2012 i686 i68 GNU/Linux Ø  “Linux“: The machine’s kernel name. Ø  “asiat16 “: The machine’s node name. Ø  “2.6.18-308.20.1.el5PAE “: The kernel release. Ø  “#1 SMP “: The kernel version. Ø  “i686“: The architecture of the processor. Ø  “GNU/Linux“: The operating system name.
$history		History command ,use to prints the history of long list executed commands in terminal list
$ cd		Change current directory to another directory
$ sqlplus		Command used to open the sqlplus programming
$ sqldr	$ sqldr control=text.ctl log=text.log	Sqlldr command user to load the data . .ctl – control life , .log – log file
$ ps	$ ps  , $ps –f	List out own running process status (ps). –f flag used to detail information
$ mkdir	$mkdir ver1	Making new directory name
$ rmdir	$rmdir ver2	Remove the directory
$ rm	$rm test1.txt	Delete or remove the file
$ mv	$mv P1.txt  p2.txt	Move or Rename file
$ man	$man grep	Online helping manual about command lists. Return back Cursor press esc, then enter ‘:’ last press q.
$ more	$mode view.html	Look at the file , one page at a time
$ cp	$cp oldfile.txt newfile.txt	Copy command. The copy data from old file and paste into new file
$ lpr	$lpr source.html	Send the file to printer
$ find	$ find .- name test.txt –print $find .-name  “.txt” -print	This command  list out all the files within directory and sub-directories in certain name
$ cal	$ Cal $ cal 8 2014	Display the calendar
$ grep  <string><File>	$ Gred “error”*	Find which files are condition certain word
$ chmod	$chmod o+rx myfile	This command used to assign / permission to access. Read, write and execute is that abbreviated as r,w,x Permission will be assign by value. For Read (r) = 4, write(w)=2, Execute(x)=1
$ Kill	$ kill %2	This command use to destroy or kill  any jobs or programs that you have suspended and are unable to restart
$ Vi	$ vi testfile	This command use to start vi text editor window. Once you start Vi editor you need to switch the program from command mode to insert mode by pressing i. To navigate around the document with the cursor keys, you must switch back to command mode by pressing Esc. To execute any of the following commands, you must switch from command mode to ex mode by pressing: (the colon key): Enter w to save; wq to save and quit; q! to quit without saving.
$ Cat	$ Cat  Header.html	You can see the content of the file
$wc	$ wc  Header.html	Count of the total number of lines ,characters and words contained in the file
$ mail [-s] [-c][-b] to-addr	$ mail –s  “Mail send” admin@gmail.com	Command used to send and receive mail. -s  => specify subject on command line -c => send carbon copies to list of user -b => blind carbon copies to list of user
$ ping hostname or  ip-address	$ ping yahoo.com	The command send the echo request to host available  on the network