Shell Scripting Tutorial for Beginners 9 - Logical 'OR' Operator Video Lecture | Complete Linux Course: Become a Linux Professional - Software Development

hello guys welcome to the next video on
shell scripting tutorial for beginners
in the last video we have seen how to
use and logical operator with scripting
now in this video we will learn how to
use or a logical operator encrypting so
let's get started so if you understood
the last concept of n the logical
operator it's really easy to understand
our logical operator so we will take the
example which we have taken in the last
video and we will you know have the
students age or anybody's age here in
the age variable and then we will just
evaluate that age if the age is greater
than 18 and in the last video we have
seen and with the end operator we have
added one more condition that if the age
is less than 30 then we will say it's a
valid age or it's not a valid age now
this time for example we want that if
the age is greater than 18 or age is
less than 30 then we will say that ages
are valid so instead of using the and
operator like this we can just use
double pipe to you know use the or
operators right so we will just take
these square bracket and in the first
square bracket you can give the first
expression and then these two pipe for
or operator and then use the second
expression which you want to evaluate
now this or if you already know is for
logical or so if any of the condition
separated by these pipe is true then
it's going to give this valid age
otherwise it's going to give the other
condition which is an else statement if
both conditions are false then the code
will go to this condition or as
statement okay
so let's run the script and let's see
what happens so our age which we have
given is 60 so in this case the age is
greater than 18 because 60 is greater
than 18 but it's not less than 30 so
only one condition is fulfilled and then
we will just run our script and we will
see what happens and it says something
is missing yeah I forgot this space here
and once again I'm going to run this
script at face valid age because one
condition is fulfilled and other is not
right now for example we will just give
some current some age in which both
conditions are fulfilled you will still
get the same answer or result they say
it's valid age right now for evaluating
the false current condition or to you
know come into the as condition for
example I gave the age 25 here and
instead of for greater then I will use
equal to here and equal to here okay and
then of course the age is not equal to
18 and of course age is not equal to 30
because it's 25 and let's run the script
once again and it will say the age is
not valid and it also gives me the
warning that this square bracket has
some problem in it so we will solve it
by giving the space here once again and
then once again we will run the script
and it saves age is not valid right so
this is how you can use or operators and
of course as an operator the or operator
also have some options so if you want to
use the of or operator with one bracket
and not two bracket you can just use -
Oh for or operator and the result will
be same so let's run the script and the
is the same so you can use double
brackets and those two pipes for the or
operator or you can use this flag - Oh
for the Opera auto operator with single
square bracket and the last way you can
use this is using the double square
brackets and in here you just need to
give double pipes once again as you have
seen in the end operators also and the
condition still will be the same okay so
as the end logical operator you can use
the or logical operators also in three
ways
one is with two brackets and these pipes
and other is with the flag and single
brackets so - oh flag and this single
square bracket or otherwise you just
need to use double brackets with the or
operator pipe so you just need to write
something like this and between the two
square brackets you can give the pipe or
for all operator okay so I hope you
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