The first command to learn is ls which is used to list the directory content.

In the shell, type
then press <Enter>
to list the content of the root directory.
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To list the content of a certain directory, put the directory as an argument to the command 'ls'.

Type
then press <Enter>
It will lead to show the contents of directory known at X11R6 available in folder usr
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The root directory contains all directories and files.

Every Linux user account has its own home directory in the /home directory and the user's login name is used as a subdirectory in /home.

Type
then press <Enter>
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Use the 'touch' command to create any new file eg: tmpfile..
type:
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'pwd' means print working directory. it is used to show current working directory.
Type
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'cd' means changing directory.
'cd /' means changing directory to the root directory.
Type
By pressing 'cd' alone without any parameter, the shell goes to the user's home directory.

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Type
and press <Enter>

The command copies the file 'tmpfile' (you have been already created using touch command ) to another file called 'tmpfile1'.
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Type
and press <Enter>

This line of command creates a directory called tmpdir.
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Type
and press <Enter>

'mv' stands for move.
This command moves the file tmpfile to the directory tmpdir.

The '/' sign is optional which means tmpdir is a directory.
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When you input
the shell appends the 'tmpdir/' to the working directory, i.e. /home/bdg

So, 'tmpdir/' is relative to your current working directory.

You may also list the content of the directory with its absolute path, i.e.
ls /home/bdg/tmpdir/
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In different types of shells, '~' refers to the user's home directory.
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In this case, means listing the contents of /home/bdg/tmpdir
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Type
and press
The parameter 'l' means long listing.
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Use

ls -a

By default, entries starting with '.' are not shown unless you use 'a' as a parameter.
You may use 'l' and 'a' together.

Enter

ls -al ..

The content of the upper level or (/home/) is printed. This is because '..' refers to the upper level.
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Type

cd

without giving any argument.
Run

pwd

You can see that you are now in your user directory. This is because running 'cd' without any parameters will return you to the user home directory.
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To move files, run

mv tmpfile1 tmpfile

where tmpfile1 is the source file and tmpfile is the destination file.

In the content list, the source file has been 'moved' to a new destination file. This action is equivalent to a rename.
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Run

mkdir tmpdir2

to create a new directory called tmpdir2.
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Run

rm tmpfile

to remove the file called tmpfile.
The file will disappeared.
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Run

rmdir tmpdir2

to remove the directory tmpdir2.
The directory tmpdir2 has disappered
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Run

rmdir tmpdir/

to delete the directory tmpdir.
You are not allowed to perform this function if the directory tmpdir is not empty.
Run

rm -r tmpdir/

where the parameter 'r' means removing content in the directory recursively.
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Go the the /bin directory.
This directory contains many of the Linux commands we frequently use.
For example,

cp, ls, mkdir, mv, pwd, rm, rmdir and touch

are all here.
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In your user home directory, create a directory called tmpdir1.
Create an empty file in the tmpdir1 directory.
View the content of that directory to make sure the file has been created.
Run

ln -s tmpdir1/ tmpdir2/

'ln' means link.
This command links tmpdir1 to a new directory called tmpdir2.
List the contents of the directory and you will see the two subdirectories.
List the contents of the directory called tmpdir1and you will see the content of the directory.
List the content of directory tmpdir2and you will see the content of the directory.

You see that the content of tmpdir2 is the same as tmpdir1.
This is because tmpdir2 is a link to tmpdir1.
Go to tmpdir2
Create a new file in tmpdir2
List the content to make sure the file has been created.
List the content of tmpdir1.

"../tmpdir1" means going down for one level. (/home/bdg/) means going up for one level to tmpdir1

You will find that the file has also been created in the tmpdir1 directory.

Linking is very useful in Linux operations. Later, you will find it especially helpful during software setup.

Go to the /home directory.
Create an empty file called tmpfile1.
You will find that you are not permitted to create this file.

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