Shell Scripting Tutorial-9: See What's In Using 'ls' Video Lecture | Shell Scripting: Discovering to Automate Command-Line Tasks - Back-End Programming

hello guys my name is mutter and welcome
to my channel this is the ninth tutorial
in the series of tutorials on shell
programming now in this tutorial we're
going to check out the LS command LS is
used to see contents of directories
that's what it's basic job is now what
I'm going to do first is I'm going to
use cat and I'm just going to create a
test file in my home folder right I'm
just gonna put some random text in it
like I am feeling hungry and I'm gonna
in it that is save it clear the terminal
cone my home folder and see that my
father is there now in all the previous
tutorials whenever I create a file or a
directory using the terminal I go in the
home folder by clicking on places and
then going on the home folder without
minimize the folder so I click on it and
then I see where my file or folder is
and whether it has been created properly
or not now if I want to do that to the
terminal then I can and the command to
do that is LS if I type in LS in the
terminal and press ENTER I see that all
of my folders and files in the home
folder are being displayed in the
terminal I have desktop documents
downloads music pictures public shell
scripts templates Ubuntu one and videos
as directories and I have two files
examples dot desktop and test now test
is a file that I just created and LS
tells me all the files and folders that
are there in the home folder but what if
I want to know what is there in the
Documents folder I can either change my
directory go to documents and then type
in LS and I can see that I have two
folders in there one is the test folder
and the other is word sheets or instead
what I can do is I can simply type in LS
documents
if I press ENTER I see the same thing so
that is what Ellis does in its most
simple form now what if I also want to
know about the file permissions or the
directory permissions of the files and
folders in my directory if I wish to do
that then I'll have to type in LS and
I'll have to execute it with the - L
option - L is for long listing and if I
press ENTER I see that the first
statement on the screen is total 48 48
is the number of blocks that are
occupied by all the files and folders in
this directory combined together one
block is a block is basically a unit of
memory that is used for memory
organization by UNIX and you know I mean
by default I'm not sure about this but I
guess a block is equivalent to 1,024
bytes yeah yeah that has to be correct
so there you go you see all the files
and folders and it's interesting to note
that in the rows where I see my folders
for example in the row of desktop or in
the row of documents my first column is
a you know is different from the first
column of tests in tests I see a -
whereas for templates or documents and
downloads
I see the alphabet D which indicates
that these are directories so a - in the
first column would indicate that the
file is a normal file or an ordinary
file whereas a D would indicate that
it's a dietary or a folder the next
three columns tell me about the
permissions to the folder or the file
for the owner of the folder or file so
for the desktop folder the owner has
readwrite as well as execute permission
the group just has read permission
sorry read and execute permission but
does not have write permission which is
indicated by this - err
and other people also have read as well
as execute permission and do not have
the right permission and similarly you
can also understand about the files now
you would also be interested in knowing
whether hidden files or folders are
displayed using LS or whether they can
be displayed using LS or not now what
I'm going to do is I'm going to first
create a document an empty file and I'm
going to call it a new but one naming it
I'm just going to put a dot or a full
stop in the name before the first
character end and if I press ENTER and
if i refresh my folder then I see that
my file is no longer being displayed now
this hasn't mean that my file has been
deleted it just means that my file is
hidden right and if I want to view my
file again then I can either press ctrl
H but that would also display a lot of
other files and folders that are hidden
by default in the home folder but I can
search my file here dot new has to be
somewhere where is it where is it
here it is dot new and if I want to do
the same thing using the terminal let me
first clear the screen for you I can
execute LS with the - a option which
means display all and you can see that I
see lot of files and folders and I can
find my new file right there with the
dot right so that is the advantage of
using LS with - a option you can see all
the files and folders in your diet tree
that's pretty much it I just wanted to
give you guys a brief insight into LS
and as we move in the course I'll talk
about LS and few more a few more
interesting options that come along with
it but this will get you started so see
you guys in the next tutorial and the
next tutorial we learn how to change
default file permissions and we learned
to do that using chmod command and we
also learn about how to see the system
settings in the system name and other
information relating to the operating
system using you name so please stick
with me thank you so much for watching
this tutorial
and I see you guys in the next one