Basic Commands

List of Basic Commands in Unix

#  --> root user prompt. $  -->  user working prompt. $ log name  --> displays current user name. $ pwd  -->  present working directory. $ date  -->  Display current date & time. $cal  -->  Displays current month calendar. $cal 2020  --> particular year total months. $cal 04 2020  -->  2020 year 04^th month calendar. $who  -->  To display the information about all the users who have logged into the system. $ who am i  -->  It displays current user name. $ finger  -->  It displays complete information about all the users who are logged in. $ uptime  -->  How log server up & running, how many users connected and load avg time.   $ which (Or)  $ wher    -->    Given command location EX: Which date   $tty    -->     Terminal position. $df      -->    Displays disk free size $du      -->    Disk usage information $clear    -->     To clear the screen   Creating files:

• Cat (concatenate): It is used to create a file and display, appending the contents of a file
• To create a file:

$Cat>filename Hello world Ctrl+D (To save the file)

• To Display the content of the files:

$cat<filename (or) $cat filename  

• To append the data in the existing file:

$cat >>filename ------------------------- ------------------------- Ctrl +D (To save)  

• Touch: To create multiple files but all are empty.

Syn:  $touch file1 file2 file3 ……………..filen                Ex: $touch file1 file2 file3

• Ls: Displays the contents of a directory.

  Options: -    r    -->Reverse -   i    -->inode  -a  --> hidden  -   l  --> long list -R    -->Recursively -   h  --> human readable   Mkdr: Creates a directory. Syn:  mkdir <Dirname> $mkdir linux

• To create multiple directories:

$ mkdir dir1 dir2 dir3 -----------------dirn

• To create a nested directory:

$ mkdir –P world/asia/india/ap/hyd Parent

• To check: $ tree world

(or) $   ls – R

• Navigation commands:

Cd:  Changes the current location. Cd.. --->To go one level back cd../.. ---> To go two levels back cd --->To change user’s home directory. EX: $ cd world $ ls Note:  The trailing slash (1) is optional when you’re using the cd command. It indicates that the name being specified is a directory. EX:  $cd Documents/

• CP: Copies files or directories form one location to another.

Syn: CP [options] source destination --- R   --->  copies recursively --- f     ---> Copies forcefully --- V  --->  provides verbose output   EX:       $ CP file1 file2   ------------>  one file to another. $CP file1 file2 Documents   ------------>   Multiple files into directory. $CP  -R Documents unix ------------>one directory to another. $ CP –rvf Documents unix world/asia/india/ap/hyd $ CP /var/log/messags ------------>  (.) represents current location.

Learn more about Linux Interview Questions in this blog post. 
Interested in mastering Linux ? Check out this blog post to learn more Linux Training

• MV: Moves or renames files and directories.

Syn:   mv [options} SOURCE DEST --- V   --> verbose

• Rename the file by specifying the file name & new name of the files

Mv messages messages.bak  

• Move it to the test directory for safe keeping:

Mv messages. Bak test/ $ls test

• Rm: Deletes files or directories

Syn:  rm [options} FILE ---    i  ---> interactive ---   r ---> Recursively ---   f  ---> Forcefully

• Delete the messages.bak file:

$cd test $rm   - I  messages. Bak

• Delete the test directory:

$ cd .. $ rm  - rf test/

• File: Displays the type of a file

Syn:  file <file name> Ex:  $ file test1 Test1: empty $ file /etc/passwd Password : ASCII test. For indepth understanding of Linux click on

• Features of UNIX/LINUX
• Architecture of O/S
• UNIX Introduction
• Basic commands
• User Administration