Shell Scripting Tutorial-42: Rant & Little Work Video Lecture | Shell Scripting: Discovering to Automate Command-Line Tasks - Back-End Programming

hello guys my name is Marvin welcome to
my channel this is the forty second
tutorial in the C's of tutorials on UNIX
shell scripting in this tutorial we're
not going to learn anything important
but I just want to talk about a few
things that have been troubling me over
the past few days I have been receiving
a lot of messages from my subscribers
and you know other viewers on YouTube
and people have told me that they find
the content of my tutorial satisfactory
but they also find the audio quality of
my tutorials pretty sucky and I don't
blame you guys I am myself I'm pretty
annoyed and fed up of the audio quality
and the weird background noise of the
computer fan that you hear and you know
I just want to tell you that I record
these tutorials on my laptop and I just
have three gigs of physical memory and
my laptop's fan you know maybe there are
dead mosquitoes or eatables in the fans
compartment it just makes this weird
knowing sound you know I don't know what
to do about it
I've already started using a different
recording software and this one has an
audio enhancement feature that somehow
allows me to cut you know some portions
of the noise but you know while it does
that it adds you know an equally weird
noise of its own and you know that's a
running tap and you know I really think
I need to get a microphone and I will
get one pretty soon but I want to thank
you guys for the feedback that you've
been providing me consistently it very
means a lot to me and you know this is
not a one-off thing I'm not you know
just going to record the series in stock
I'll probably you know upload few more
courses and you know there are other
programming languages that I have been
using over the past few years and you
know I will record and upload more and
more tutorials not just on shell
scripting but on PHP in JavaScript and C
and C++ and you know Python and Perl
anyway that's enough talking if you guys
remember in the 30th tutorial in this
course I told you guys how to compare
two numbers but in that tutorial if you
guys remember I consider the example
that involved the integers I didn't you
know take any example that
real numbers so what I want to tell you
guys is that you cannot use the hyphen
EQ with real numbers so I have my text
editor here and I've saved this part in
the home folder it's for tests and has
the extension SH what I'm going to do in
this tutorial is I'm going to first show
you the method in which you would you
know ideally want to compare to real
real numbers and that is by using - EQ
and then I will tell you why it won't
work and then I will also show you the
right way to do it right so I'm going to
first declare and initialize two
variables and I'm gonna give them the
same value so I create a variable a and
I'll give it the value 4.5 now create
another variable B and I'll give it the
same value right so when you use D - EQ
operator then you should you know the
operator should tell you that both these
numbers are same but it won't do that
let's see so within my square brackets
output the task condition dollar a - EQ
dollar B and I check the exit status of
this test condition save this file bring
up my terminal and execute the script
and there you go it tells me that on
line three four point five is an
integral number and then it also
returned the next the star is two now we
have just encountered scripts that
return X star is 0 and 1 and 0 as I told
you guys means success and one means
failure now what is to mean to tells you
that you know there is obviously you
know failure because your script is not
producing the right output or the output
that you were expecting but it also
tells you that you've done something
illegal you used a you know maybe an
operator or a command or something you
know in an incorrect manner so that's
what these significance of two is and
you know the right way of doing this
would be to treat both these numbers as
strings right and that's how UNIX stores
them and you know it won't really make
much of a difference if you would put
double quotation marks around these
variables in your test condition and if
would replace this - EQ operator with an
equal to symbol so now what we've done
is we change a mathematical test
condition to a string test condition so
daughter a will now be treated as a
string that is for with a full stop and
the symbol five and dollar B will also
be through it in pretty much the same
way and the equal to symbol in between
we'll make sure that this test is
evaluated as a string test and not as
number two so let me save this part and
let me clear the screen first and when I
execute the script you see that we get
the exit status zero which means that
the test was executed successfully so
there you go I mean you know this is a
one thing that skipped my mind while I
recorded the tutorial on running checks
on numbers so I thought I should you
know maybe discuss it in this tutorial
so anyway once again I want to thank all
my viewers for being so supportive and
I've received really nice comments over
the past few weeks and I'm really
encouraged to record more and more
tutorials for you people so I see you
guys in the next tutorial where we will
discuss something interesting and
important thank you so much for watching
this one and please subscribe to my
channel