Linux Command Line Tutorial For Beginners 21 - which and whereis command 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 I'm going to
show you how we can use which command
and what is command in Linux so let's
see first of all what is which command
and how we can use it the which command
is used to you know return the part name
of a file or a command which we use with
this which command so let's see how we
can use it so to use the which command
you just need to write which and the
command a name so for example Alice ok
and this will give you so for example I
will press ENTER and this will give me
the location of this LS command or
wherever this LS executable is located
right for example in the last video I
wanted to know the path location of the
bash so I have done something like this
which bash and it has given this
location to us right now this which
command will help you whenever you will
be writing much of the bash scripting
and in bash scripting it's a good
practice to you know use the full path
of the command line name so instead of
using LS in bash scripting for example
so let's open our script first of all
Nano which we have created in the last
video so I'm just going to open the
first of all CD to the desktop and then
Nano to my script which we have created
in the last video right so in Linux it's
in best scripting specially it's a good
practice to use the location full
location for example bin slash forward
slash LS right which is the full
location of this LS command and then I
will just you know exit out of it and
whenever I execute this my script once
again it will give me the same result so
sometimes whenever you use your script
in different operating system some
recognizes your Alice command some wants
you to give the full path of the for
example any command which you use so
this is the full command so this is
where the witch command will be helpful
to you to know the location of any for
example command for example I want to
know the location of let's say Firefox
and press enter and you can see it's
located here so user bin Firefox right
so for example I want to know the
location of cat so bin cat right so in
this way you can know the location of
any you know command using this which
come on now what is a what is come on so
let's see how we can use what is command
so I'm going to clear the terminal and
then this time we are going to use the
what is command so what is command is
going to display the short manual page
description so as I have been you know
telling you to use man pages for example
man LS and I will just press ENTER it
gives this man page which gives the
information about you know LS what it
does and essentially this what is
command is going to return you short
description of this LS command which is
there in the main page for example this
description so let's see how we can use
this you know what is come on so just
write what is something like this and
then LS and press ENTER and you can see
it gives the short description of this
LS command which is there in the main
pages itself so if you wanted to know
what this command is doing so you just
can just do what is LS or or any command
so let's say I want to do what
is a Firefox for example and it gives a
free and open source web browser for
Mozilla right and this come on which we
haven't seen for example grab we will
see it in the later video what is it but
let's see what is it so it is used to
print line matching a pattern right and
let's say what is a cat command and it's
a concatenation so it is used contact
catenation files and print on the
standard output so what is command you
can use to display a short description
of a command which is present in the man
pages also so this is how you can use
which and what is command in Linux I
hope you have enjoyed this video please
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