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Linux- Lesson Primary(simple steps to feel Linux easy)


                                                         SIMPLIFIED LINUX
                                                    ``````````````````````````````````````

Tip Number 1: This is the most important tip I want to give you fellows.

                                  PRACTICE WHAT YOU STUDY


Red Hat/Cent-OS Terminal Commands
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Before studying these commands isn’t it necessary that you should know how to open the
terminal……!

Here is the way.

In the top bar, click Application -System Tools - Terminal

Or for smart guys :)

If you wish to open terminal without using mouse, then press Alt+f2, then type gnome-terminal

Or
 just left click and click open in terminal

Commands
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1. pwd - It stands for Present (Print) Working Directory. It shows where we are now standing while in
terminal.

Syntax for the pwd: pwd

To know the present working directory just type ‘pwd’ without quotes.

2. touch - It is used to create a file in the Linux.

Syntax for touch : touch file name

E.g. : touch sample_file.txt

The above command will create a file called samplefile.txt in the present working directory.

From now onwards keep in mind ‘pwd’ stands for Present (Print ) Working Directory.

To create a file in a place outside the pwd() the syntax is

touch path/file-name. extension

E.g. : touch /home/user1/file1.txt

We can create multiple files using the touch command. One example is shown below:

touch /home/user1/file1.txt <space> /home/user1/file2.doc

You must add space between the first and second path. Ok.. :)

I hope you have noted that space should be added in between touch and the starting of the path;

i.e. between touch and /home/user1/file1.txt at here. For every touch command this is the format.

In Linux a file can also be created without including a file extension:

E.g.: touch hello

The above command will create a file hello in the pwd.

3. cd - The command ‘cd’ stands for change directory. This command is used to change our current

location. That is to change the pwd ;
 cd command is used.

Syntax: cd location

E.g.: cd /home/user1

4. ls – The command ‘ls’ stands for list. As the name suggest the command is used for listing; listing the

contents of a given location. That is to show what all things are in a given location or path.

Please keep in mind: The content of location is different from the contents of a file or folder
.
Syntax: ls location

E.g.: ls /home/user1

Like ‘touch ‘ ; ls can also be used with multiple locations given.

E.g.: ls /home/user1<space> /home/user2

There are different options that can be used with ls that is known as the switches of the ls command.

Many commands have switches with them. I am gonna say some of them. Detailed description about

them can be found in then man page of the ls.

To open a man page syntax is given here:

Syntax: man ‘command name’

Give the command name with out quotes

E.g. : man ls

The switches that can be used with ls are:

1. -l : To list the files and folders in the parent folder with the properties.
2. -a : To show the hidden files also with the files in the folder
3. -C : To show the files in the column wise manner. That is from top to bottom view.
4. -d : To show only the directories in a folder.
5. -x : To show contents alphabetically in row wise
6. -g : Similar to -l but do not show the owner of the displayed contents
7. -h : Used in combination with -l and use if for displaying file size in human readable format.
8. -i : Shows the inode of displayed contents(inode- a number created when creating a file/folder/any
element in Linux)
9. -r : Shows the reverse order while sorting. Used in combination with -l
10. -S : Shows the files in sorted order based on size
Please refer the man page for the rest..
E.g. ls -l
ls -ls
ls -d


5. clear – The command is used to clear the screen.

Syntax: clear

E.g.: clear

The screen at here is the terminal screen. The place where we type our commands.

Short cut for clearing the screen- Ctrl + l

6. mkdir- The command is used to make a folder/directory in the Linux.

Syntax : mkdir directory_name

The above command will create a folder/directory in the pwd ; i.e. where we are standing in
terminal.

E.g.: mkdir sample_folder

To create a directory somewhere else other than pwd e.g. is shown below

E.g.: mkdir /home/user33/folder3

The command mkdir can also be used to create multiple directories similar to ls and touch.

Syntax: mkdir <space> path/folder_name <space> path/folder_name

E.g.: mkdir /home/user1/fold1 /home/user2/fold2

5. rm – remove

The command rm is used to remove a file/empty directory. i.e. An empty folder/directory or a file.

Syntax: rm <space> file name

E.g.: rm file1.txt

rm file2.txt<space> file3.txt

To delete a non empty directory use the following syntax:

rm –r <file name>

r – here r stands for recursion. i.e. to delete files and folders inside the non-empty folder/directory.

More info is on the way...
Please refer and help me make this better friends.
                                                                            Waiting for your valuable feedback
                                                                                                     Jaison


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