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Perhaps the strangest expansion is called the Brays expansion.

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Actually, let me write that down here.

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So the in this lecture we will learn about the brace.

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Expansion.

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So.

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A we it with the brakes expansion, you can create a multiple text strings from a pattern containing

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braces.

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So for example this here let me change this to here.

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So echo for example.

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And make it Oxley.

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And A, B, C, D and academy.

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And as you can see here, we can here.

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This is the following output.

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Occella Academy.

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Occella.

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B Occella.

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C Academy.

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Occella.

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D Academy.

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So patterns to be expanded may contain a leading portion called the preamble and a trailing portion

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called a postscript.

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So the brace expansion itself may contain either a comma separated list of strings or a range of integers

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or a single character.

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So the pattern may not contain unquoted whitespace.

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So here is an example for example.

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Echo.

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So now.

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We will.

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Right.

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Following example lectures.

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Lecture number.

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And here for example.

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Lecture number from one to.

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20 here.

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Not like this.

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Here.

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That's it.

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And as you can see here, lecture number one.

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Lecture number two, lecture number three, four, five, six, seven, eight.

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And from two, from 1 to 20, I think you are getting the.

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Logic of this expansion here.

42
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So now we can also do it like that.

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So clear.

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Clear.

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And echo zero one from zero 1 to 99 here.

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And we will get this following output here.

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And you can also do it from, for example, 0010012099.

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And you will also get this output.

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So if you try that sometime, something like that.

50
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And here you will also get the same output because it starts with 001 and then ends to 99.

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Here you can also do something like that, for example.

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Echo.

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Echo.

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You can use the range of letters in a reverse order like this.

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So from Z to A and here and as you can see here, we got from Z to X.

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And lastly A here for so we reversed the letters here.

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So and you can also reverse this numbers here.

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So you can also write from 99 to 1.

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So for example, echo 99 to 1.

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And here you can also do it from zero 99.

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Zero nine 9 to 1, and you can also do zero 99 to 0 100.

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And as you can see here, zero 99 and lastly, zero 100.

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So let's think of like that.

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What is this good for?

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The most common application is to make lists of files or directories to be created.

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For example, if we were photographers and had a large collection of images that we wanted to organize

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into years and months, the first thing we might do is create a series of directories named for example,

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and actually let me write it down here so you will understand better.

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So the first thing we're going to do is create a series of directories named, for example, year.

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Year and after month.

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So.

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So this way the directory names would sort in a chronological order and we will type out a complete

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list of directories.

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But that's a lot of work in this case.

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But in and it's error prone.

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So instead we could do here in next example.

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But firstly what we want to do here for example October, October.

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And the month is going to be, for example, no year year for.

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So first we're going to write a year here.

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So year is going to be, for example, 2020 4th October.

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And inside this we're going to have the photographs.

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So this is going to be directory here and this is going to be our directory.

83
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And inside this we're going to save and order photographs in it.

84
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So let's get started with our example now.

85
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And here.

86
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But first we're going to here.

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So firstly, we're going to go to documents or another directory.

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So we will want won't see the other users directories here or let's actually go to CD, my dear one.

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And so we don't have any files in it.

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That's good.

91
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And for example make their photos yet.

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Yeah, photos.

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And here we created the deer photos.

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So we're going to see the two photos here.

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Photos.

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And now.

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We will make the deal here.

98
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So now that's here, for example, my card here and from 2024 or 2022.

99
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From 2020 to.

100
00:06:07,510 --> 00:06:12,970
2025 and here and we will also write the month number.

101
00:06:12,970 --> 00:06:15,640
So in this case, the month numbers is going to be

102
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010203040506.

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Also

104
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070809.

105
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Uh, not zero here.

106
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Ten and 11 and 12.

107
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So the months order is going to be like this here.

108
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So let's here in order to do that, we will write it.

109
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012.

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12.

111
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And here let's create enter and here, let's see the magic here, LZ.

112
00:06:56,330 --> 00:06:58,790
And as you can see here, LZ here.

113
00:06:58,790 --> 00:07:04,460
And as you can see here, actually, we did an mistake here because we did write it like that.

114
00:07:04,460 --> 00:07:09,980
So now let's actually see what did create, uh, we what did we create?

115
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And here, as you can see here, we created actually we did mistyped the error.

116
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Instead of writing this, we need have to write two space characters so clear, let's write it again

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so we don't have any files.

118
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LZ And here.

119
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We will do m-code here and from 2020.

120
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To 2025.

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And here.

122
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Zero one from zero one.

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To 12.

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And here, as you can see here, we did create our folders for it.

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So, for example, this is 2021, 2022, 2023, 2024.

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And it goes like this to from 2021 to our 20 2512 here.

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And this is pretty like magic, right?

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So in next lecture you will also learn about the parameter expansion.

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So I'm waiting you in next lecture.