Hello and welcome to this. Cali fundamentals
lesson. I'm very excited to be here with you today.
And so we just got done working in
the terminal and doing some things of that nature and now we're
really going to focus on the file system. So
you may have been asking yourself. How do I better
understand the file system? How do I know where things around? What
do I need to understand? Well, the good news
is in this lesson. We're going to give you a high
level understanding of the file system not just with Cali but
any Linux distribution that you're working with and then
a high level understanding of permissions. And so
to get us started. Let's touch on that color coding
we discussed in the previous lesson. Now, there
are a few other colors as well
as these but these are the ones we wanted to touch on with respect
to this particular lesson. And so remember blue
when we were looking at the desktop folder and
things of that nature and our root directory. Well that represents
a directory so
Blue in this color similar that's a
directory green is going to be executable or recognized
data files. Sky blue is symbolic link
files yellow with a black background is going to be devices
pink is graphic images red is
going to be archives Zips things that nature and red
with a black background is going to be broken links
and things of that nature so very easy
there to kind of get into and as you work more with the
file system and do the distributions Linux or otherwise, you're
going to see these colors a lot.
Now, let's jump into the file system. So the Linux
file system follows the file system hierarchy
standard or FHS and in
Cali's case. This is no exception. So here are
a few key directories we want to touch on and we'll
look at a high level overview of this in a
moment. So Ben is where you're going to see basic programs. And
so as you can see here, we did a PWD in an LS of
that Ben folder or directory and it's got things like
LS and mkder and
essentially when we were running those commands it's looking here for
the directions on how that works. And so that's got
basic programs and things of that nature and Ben
and then root is where we had our desktop folder and
where we'll have the the basic kind of
images or anything that we save under our root account. It's going to
be here in our personal files in that route directory. MNT is
a temporary Mount Point directory. So if we
Mount any Media or anything of that nature, it's going to be showing
up here Etsy is configuration.
Files and things of that nature as you can see here with Etsy LS what
we found was like ice weasel
and some other config files and profile information
and whatnot is going to be located in that
Etsy directory and then Dev down
here. We've got devices and device files essentially
that are going to be in this directory.
Now a high level overview of how the file system
looks is represented here. So we started
off in this route directory previously and then when
we did that CD dot dot command it brings
us here and from here we were able to see all of
these different points in the system and
then we can navigate down and drill down into each of those and
so as we discussed earlier with like Ben we've got
essential user binaries here. So like the ls command
and make sure and ping and so as
you enter those commands in the terminal it's referencing
here for those. So if you were to accidentally delete to delete
like Ping and then try to Ping later shouldn't work
because now you've deleted the reference point in the binaries that make
it work. And so same thing here at Sea in
here has config files. So like we've got
different areas that you can see here that would have
configuration files and things that nature ESPN has
some essential system binaries Etc.
And so as
Getting through this and looking at the file system. You don't need to really memorize
the layout just know that you know, if you're having
issues or your troubleshooting something and it's command-related or
if it's configuration related. We'll
get into like how to make some changes in the in the
configuration files and things of that nature later. So for now have
a quick reference be kind of aware of where things
are at, but don't spend too much time trying to memorize everything.
All right quick check on learning. So as
we were discussing earlier with colors and things of that nature
in these in the file system, which one represented
a directory.
All right, so remember green was an executable.
Pink was a graphic image file.
Read was an archive file blue represents
a directory. So if you see not sky blue,
but that darker blue that represents a directory
like the desktop folder or something of that nature and then
configuration files are located in which directory so
remember root was the personal files
for us Dev was our device files
and things of that nature Mount represented temporary
Mount points and things like that for media Etsy
is where we had configuration files
with respect to this file system.
So all of that is good, but you may be wondering what
about permissions and things that nature I mean has that
crossed your mind. I know it's Crossing mine. So let's jump into
a quick overview on permissions now don't get
overwhelmed just note that this may be
a good quick reference. You can also, you know, use Google
and find some represents references that are you know
more your style but looking below here. We
did a quick LS -
Hmm. Nope, see I did a cap there. That's
not right. You can't do capitals LA and what that
does is it provides this output in the directory?
Now when you're thinking of permissions, you've got zero to seven
here and each of these numbers gets higher and higher
as the level of permissions as we go through here. So when we get to
number seven that gives us read right and execute permission
now, you'll notice that there are several groups
of letters here. So don't worry about this on
the end. It's either blank or d and d means
that you've got a directory see that blue color there on the
end when it's blank. It just means that it's not a
directory. It's you know some other file type. So this is broken down
into three sets essentially here of
letters and that's represented as
user.
group
or other now as you're thinking about these permissions. I
took the time here to kind of lay them outside by side.
So looking at zero it's represented as such execute would
be represented in each of these As an X.
Now, it could be different. You can have any combination of these three
user group and other and the
permissions like, you know in group could be read write execute. I
can have nothing in user and nothing in others.
And so I can have a combination of any of
these read right and execute someone we're looking here at this
particular at deny.
That means that they're is reading
right on the owner so r&w and then
we've got just read on the
group and nothing on other. So how to
keep them in mind. That's a high level dive into permissions use a
reference to help you get through that if you're thinking about
inheritance and things of that nature just think of it is going in this
direction. So if you've got read write execute under
other and everything else
Is blank then no matter what the user or group you should
be able to read write or execute that file or directory.
And so this is is the equivalent of the windows.
Kind of everyone on my sorry handwriting
here, but everyone essentially is in other
and then it's defined by group and then user which
is typically the owner and things of that nature. So go right to
left when looking at these and defining what
the true level of access is when you're working through those but don't
get hung up on permissions just know zero through
seven as we get closer to seven that's like full permissions on
any given area here and it's broken
down into user group and other so with
that in mind, let's do a quick check on learning which number
provides everything read write
and execute permissions.
all right, so remember
You we didn't go through the numbers entirely two
is right.
4 is read
six is read write which you should have caught was read
write and execute which is all three everything that
we can do and that was represented as a seven
now.
With all of those things in mind and everything that you just learned, what
did we pick up on? What should we remember? Well, we looked
at colors the blue green pink red directory
executable graphic image archive file.
So those colors are important as we navigate through the file system,
and we're understanding what things are and what they mean. We
did a basic overview of the file system layout in
the fall hierarchy standard and a high level
overview of permissions zero through seven, so I
want to thank you for your time again today. We've learned so
much together, and I look forward to seeing you again soon.