Linux Command Line Tutorial For Beginners 4 - cat command in Linux Video Lecture | Complete Linux Course: Become a Linux Professional - Software Development

hello guys welcome to the next video on
Linux command line tutorial for
beginners in this video we will learn
how we can use a cat command
in Linux cat is one of the most
frequently used command on linux it has
three related function with regard to
text files one is displaying the text
while second is combining copies of text
files and third is creating new text
file so let's see how we can use cat
command so I will just press ctrl alt T
to open my terminal so I will just press
control alt E and it will open my
terminal now the syntax for using cat
command is you just need to write cat
here and then you give options so just
give some options and then you give the
file name so for example file1 file2 and
so on okay something like this so let's
see how we can use cat command
so first of all you can just give cat
and press enter and you can see our it's
giving us this kind of cursor so we can
just type for example hello world and
then press ENTER and echo whatever input
we have given right so once again I can
say echo input and press ENTER and it
will echo it again so you can see this
is the basic functionality without any
option for the cat command
but cat is not only the echoing you know
program it can do much more than echoing
something so to exit this cat command
you can just press control D which means
the end of the file so just press
control D and you are out of this cat
command right now first of all let's see
what files we have in our folder so I
will list all the files in the current
folder which is my home folder and you
can see these are all the files and
directories in my home folder so for
example I have this file called list 1
dot txt okay and I will just show you
what are the content of this file so
this file contains three lines line 1
line 2 and I have a line break or a
blank line here and then I have the
third line ok
so I want to print this text file on my
terminal so I can use a cat and then the
name of the file so the name of the file
is list 1 dot txt and press ENTER and it
will display me the content of the file
same as like this ok now for example I
want to show the content of two files so
you can see here I have list 1 dot txt
here and I also have list 2 dot txt also
right so I will just show you the
content of list 2 also so I have once
again three lines and one blank line
here right so for example I want to
display the content of both the files I
can just add one more file name here
list 2 dot txt and press ENTER and then
it will combine the content of both the
file and display me on this terminal
right so the first
use of cat c'mon you can say is for
displaying the content of a file right
or multiple files now there are some
options related to cat command
so for example I want to show the line
number on the every line of the content
of the file for example so I can use a
cat and then minus B which will add line
number to non blank lines okay so I will
just give the name of for my list one
dot test koala example and press ENTER
and you can see it adds the line number
to the non blank line so you if you
remember my list one have one blank line
here right and it will skip or it will
not add the line number to the blank
line but all the lines which have sub
content it will alt add the line number
to them now next command first let me
clear the terminal and press Enter so it
will clear the cut terminal the next
command is cat - and and what it will do
is it will add line number to all the
lines so for example I will just say
list one dot txt and press ENTER and now
it has added the line number to the
blank line also right now for example I
have a text file which have multiple
line breaks something like this a big
line breaks right and I want to you know
display the content of the file and I
want to remove this these all line break
big line break and I would just want to
show only one line break right let me
save this file and then I will just say
cat and I will just give the come
on - s and then the name of the file
lists one dot txt and press ENTER and
what this command does is it squeezes
blank lines - one blank line ok so here
there can be many lines but it'll you
know squeeze all the blank lines
- only one blank line and it will not
affect the content of the file remember
it will only display the content of the
file in this format right so it's not
changing the content of the file but
only displaying it in our convenient you
know manner right now the next command
is cat - capital e c'mon so I will just
remote my changes here and I will save
this file and now I will just give cat -
capital e and then I will just once
again give this list one dot txt right
and then it adds this dollar symbol at
the end of each line ok so you know that
this is the end of the line ok so these
are the basic commands and option
related to cat command now if you want
to know more options related to cat you
can just enter man if you remember in
the earlier video I have shown you how
to use a men pages so just you use men
and then just enter cat and press ENTER
and then you will be able to see there
are more options related to cat command
for example - a which means show all or
- E which is equal into - ve or these
are all the options which you can use
with cat command
I just showed you the most important
options with cat command
so just use
- you know read or learn more about this
cat command and when you press Q you
create the these man pages now the cat
command can also create new files but
this we will see in the next video when
I will show you how redirection works
using command line okay so this third
functionality of cat we will see in the
next video so I hope you enjoyed this
video please rate comment and subscribe
and bye for now