HOW TO WORK ON TERMINAL
When we talk about Linux, then first thing comes in our mind is
that- how to work and where to work?
Usually, we
operate a Linux-based system through a Command
Line Interface (CLI) or a Graphical
User Interface (GUI). We usually interact with a modern UNIX shell
using a Command Line Interface known as TERMINAL
EMULATOR Window or some separate Virtual
Console. Common terminals as we know already are- xterm and GNOME Terminal.
WHAT IS A TERMINAL?
Terminal is the graphical platform where the commands can be executed. There
are various other terminals used in different Linux-based System. Commands tell the operating system to perform set of operations. All
these commands are going to be written in a command line interface i.e.
Terminal.
When we log into a terminal then
we see some text written in the terminal window as: user_name@linux_machine_name:~current_path$
Keertendra@keertendra-virtual-machine:~$
In Linux system, there is one special user for administrator, which has all
permissions and access to all files. This user is known as “SUPER USER” or “ROOT”. The Dollar sign “$”
indicates that we are not the root user and the path starts with a symbol “~”, which corresponds to “/home/user_directory/”.
User is also having
his own directory known as Home
Directory. For example:
Keertendra@keertendra-virtual-machine:~/Desktop/Linux_Programs$
Now to login as Super User or root,
we have to use a command “sudo su” then it will ask for the password,
type the correct password and we will successfully logged in as root/ Super
User. It can e verified by Pound
sign “#” instead of Dollar sign “$”.
Now the path is shown from the root “/”
directory. For example:
root@keertendra-virtual-machine:/home/keertendra#
HOW TO USE COMMANDS?
Commands
are the set of key words and arguments which are used to perform some specified
operation. In
Linux-based System, there are a numerous commands to perform various tasks. These
commands are written according to a specified syntax.
SYNTAX:COMMAND_NAME [-OPTIONS]
ARGUMENTS
COMMAND_NAME: indicates the name of the respective command say, help, man, ls, cd, etc.
[-OPTIONS]: Options are used to perform the operation on the selected item in selected manner. The
square brackets “[ ]” shows that the
use of options in the command
is optional. It starts
with a hyphen sign (-).
ARGUMENTS: arguments can be any value passed to the command to
execute an operation. The
operation is to be performed on the arguments. It can be file name, path, text, etc.
****
The Linux is Case- Sensitive. The Command_name, Options and Arguments are separated
by a SPACE (“ “) in between.
For example: a
command List command (ls) is used
here to show details of all the
files and folder of the Linux_Programs directory as-
$ ls –l Desktop/Linux_Programs/
WHAT ARE OPTIONS?
The command options are used in the
command. Some of the common command options used in LINUX are given below:
-a: it lists all the files and directories, even hidden
ones which are preceded by (“.”)
-l: lists the size, creation date
and permissions about all the files and directories in the
current directory
-d: lists the directory
-c: don’t create file if it already present
-f: force
-k: block Size
-R: recursive
-t: type
-V: version.
SOME CONTROL KEYS:
Control
Keys performs special function. The control keys used in LINUX are:
Ctrl+S (^S) : Pause Display
Ctrl+Q (^Q) : Restart Display
Ctrl+C (^C) : Cancel
Operation
Ctrl+U (^U) : Cancel
Line
Ctrl+D (^D) : Signal
end of file
Ctrl+V (^V)
: Treat
control character as normal character
SOME
BASIC COMMANDS:
1. GENERAL PURPOSE UTILITY
COMMAND:
MAN, RESET, CLEAR, CAL, DATE, ECHO, PRINTF, BC, XCAL, EXIT etc.
2. USER LOGIN AND PASSWORD
COMMANDS:
SUDO, SU, PASSWD, WHO, WHO AM I, WHOAMI,
USERADD, USERDEL, MOUNT, UMOUNT, DF, SHUTDOWN, etc.
3. FILE COMMANDS:
ls, pwd, cd, TOUCH, mkdir, rmdir, cp, mv, rm, etc.
4. FILE DISPLAYING COMMANDS:
CAT, TAC, MORE / LESS,
etc.
5. FILE PERMISSION COMMANDS:
CHMOD, CHOWN, etc.
6. FILTER COMMANDS:
GREP, FIND, LOCATE, PIPE, TEE, HEAD, TAIL, WC, CMP, COMM,
SORT, PASTE, CUT, etc.
7. PROCESS MANAGEMENT
COMMANDS:
KILL, KILLALL, PS, TOP,
etc.
8. COMPRESSING & ARCHIVING
COMMANDS:
GZIP/ GUNZIP, ZIP/ UNZIP, TAR, etc.
****if there comes any difficulty in using any command
then see the MANUAL of that respective command by using a command i.e. “man”. We
can also use “help” command
and “info” commands as well.
For example: to open the manual
entry of command “chmod”.
$ man chmod
For example: to get help on the command i.e. “cd”
$
help cd
For example: to get information about the command i.e. “mkdir”
$ info mkdir
Ok, this is
little bit sufficient for terminal commands and their usage.
