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Let's don't look at the file cross which is from the Djala doc either package it can be useful for manipulating

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files on the system that is you can use this class to do things like creating files creating directories

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deleting files and directories renaming files and so on.

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We will simply add more.

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Very we'll see some of the things that we can do with this class.

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We know that every file or directory on the disk has a certain unique but that is a part is used to

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locate the file on the directory and an instance of a file class would represent such a spot and it

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is instantiated as shown here.

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So telepresence a pop to a file order directory but not the contents of the file.

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Our first impression looking at this constructor would be that a file instance the presence contents

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of a file and that is not the case here.

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The string in the constructor is referred to as up happening not that the constructor does not throw

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an exception even if the pathname is invalid here Aalto just know that.

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But file input stream on file output stream classes have constructors which text file instance us an

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input.

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But I believe the constructors that we used which took filename as input are more commonly used on here

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are some really fundamental things which we need to know about the differences at the OS level.

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First is the directory separator in the pathname on Windows a backslash is used to separate the directories

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in the back.

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Name one on Unix forward slashes.

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There is also something called root directory which would be the first or the top most directly in the

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directory hierarchy.

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On Windows it would be drives like C and D.

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Well on Unix it would be represented by the forward slash on Unix if the bottom is G-I the slash em

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then the root would be the directory in which geode is present.

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So Geordi will not be the root but the directory in the G ID is present.

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That would be the root directory.

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Now as for the lines operators in a text file windows users garridge feet followed immediately by newline

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.

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On Unix it is just the new line coming to pathname.

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It can be either obsolete.

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Really do an absolute pathname points to the same location regardless of the current working directory

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and current What can that accrete which is also referred to as a user directory would be the directory

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in which you are Jola interpreter is running on my machine.

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It would be geoduck slash Dymo in the C drive.

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You can also know that we are the user be our system property which is accessible from the get Propertius

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method of the system class.

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Now when it comes to relate to power them it is resolved with us but what wouldn't be accurate.

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So does it relate to the working directory.

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If it is not me or it should get clear in the demo and it is actually time for the demo one I'll sort

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of switch over to our editor.

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OK in this demo we're going to look at two new methods and here they are in the IRA demo glass.

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So let's just go ahead and look at the first matter.

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And here it is.

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So here we are first creating an instance of file and we are passing a file name which is valid and

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or jpeg.

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And here it is and are jpeg within the within that demo project.

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So it is within the demo folder.

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But here we also have this.

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So within the models as sarcy directory.

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And here we are using two dots.

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So we could have just had the filename as demos slash growled and Argiope.

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But I just wanted to show this notation here.

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Here are two dots indicates that it is referencing the parent directory.

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OK.

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Which means the directory in which sources present.

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OK so that we can do it this way or we can just remove this part on hybridize just valued and Arjay

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peg written Demel.

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And here we are using an extra slash.

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It's actually only one slash but ngalo we know that slash needs to be Skipwith and there's Slash.

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So to try we have boost lushest here.

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And so these are all the different methods.

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There are many methods within the file class.

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So we are also trying many of these methods.

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So let's just go ahead and actually run it and then we can look at each of the methods

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and here it is

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OK so the get absolute bat is giving us the absolute path off the file.

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Q So you can see the entire file including Pop name including SIRC under two dots.

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Now there is something called Get canonical bot.

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So that's another matter and it would actually read the simple pathname.

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So it's not going to include sarcy.

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And the two dots.

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And here we are trying to create a new file.

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And all of these methods as you can see are invoked on F which is the end of it is a variable that is

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referencing file instance.

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So but these do not get canonical path and create new file have to be inside the try catch block.

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Uncreate you'll find we're trying to create a new file.

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But in this case since the file is already there it read and save files.

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Then the next one is separate or so here it's actually a field.

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It's not a matter it's a field unseparated gives the the operator that separates the directory so it's

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a directory separator that will get in here.

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The operator operates their directories in the path name.

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So it is a backward slash since it's Windows system on separator.

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It is also another method which simply gives the same thing it gives the same thing but it returns a

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car where whereas operator returns this string.

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Now if you're let's say if you are creating some file on a particular machine and you want to clear

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this up in some kind of a directory in some directory then you it's better to use when you're creating

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the file name it's better to use.

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You'll make use of this separator field.

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OK.

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That way it will be specific to that directory to that machine on which the program is running.

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OK.

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So I just kind of like form independent.

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No.

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So instead of hard coding the separator you can make use of this.

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So that's not I in get parents integrated into the parent off the firewall and ogic bit under the tree

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.

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That would include the entire structure until wild and Argiope EC.

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OK excluding Reiland or depict in this case it's also retaining SIRC and double dots which would mean

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only this part the G ID under Obama and the next one is Last-Modified.

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So it does run the firewall's Last-Modified and it gives the time in milliseconds so milliseconds from

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1970.

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So that's qualis the epoch time.

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And so it would be the number of milliseconds since that particular time.

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Now if you use that milieu if this if this number if you if you convert it into ears it would be around

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46 years.

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You can actually try it in Google just search for milliseconds to ears and give this number and you

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should get it.

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Next one as whether the file exists yes whether the file is a file.

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Yes it's a file on the next one is whether it's a directory.

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No it's not.

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So it's false on the next one is the lend method which will read under size of the file which is around

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5 and B.

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Next I'm printing though my working directory the user directory.

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And as we mentioned we are going to in the get property matter with the system property user Aiyar and

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my directory is this one.

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Jerry strategem on next.

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We are trying to create some directories here.

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So first thing we are doing is we are creating a new file instance passing the new directory name and

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we are doing it in a relative path.

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OK.

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We are not using the absolute path which means that my current directory is a demo Jayati and Emel unbuttoned

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them all I want to create this directory.

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So undergirds set rules.

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So let me just refresh your head fly on them all.

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And as you can see that as directory has been created so are done so true here.

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So the method for that is and.

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BAIER make that accrete.

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And next we are creating one more directory within that directory.

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So if you go here you can also see that there is the best directory that God created.

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Next we are trying to delete that as a directory.

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And here it says false.

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It cannot do it because there is some content within the desk directory.

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If it is empty which means that there is no file or not directory only that it will succeed.

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It really is not true.

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Now in the next line we are trying to create multiple directories within test directory.

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So we are trying to create a directory called test run unbid within test run we are trying to create

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another directory called Test 2 and we are using the same method maybe undertreatment pretence of.

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So we cannot do that.

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Unflawed that we need to use this as the plural form off make a bit Acree and that would allow us to

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create that directories.

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But just one.

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Understood.

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So you need to use and keep the eye on this for that.

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So that's the thing.

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And next Finally here in this matter we are creating a new instance called Temp dot DXi and we are creating

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the new file.

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I notice that the file got signed should have been created.

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Maybe the child was already there.

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Yeah I think in my test runs the file was there so it got created and after that the next step is to

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rename that file name to a different name and in order to get the argument that this method is a new

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file Newfies instance with the new name.

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But in this sense it's just not the name.

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But we are also including a directory name here as did a tree.

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So what is going to happen is this is the name of the new file.

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And since the directory name is there this file time file temp.txt is actually moved into this directory

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.

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OK with this name.

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So if you go here and test directory you can see this file 1.60.

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So that's how you load more files.

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You can move files and you can also rename them and now let's look at the second matter which is Karlos

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did reflector.

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Now sometimes we want to look at the contents of a particular directory what files and directories that

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a particular directory has on the immediate files not a directory on the Internet within that directory

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.

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But our immediate three appearing directories on files appearing in a directory.

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Now if you want to do that if you want to see what what directories on file are appearing in a particular

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directory then you would use.

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And then we can use this method for that there is a method called us list.

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So here we are creating a file instance and it is referencing the current directory and the current

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directory would be the current working directory which is there.

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And within that directory We want to list all the directories and the files that are appearing immediately

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within that.

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And for that we use the list muttered Birgitta dense string theory which includes that it would include

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all the names of the directories on those files.

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So I'm passing this but I'm going to require a placeholder which is initially set to false.

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So if it is false it means that we want to list all of them here.

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Gayford is false.

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We are going to just invoke this method.

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So here you can see that there are all these different files and these are all files are in some directories

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here underground and Argiope quite also is here.

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Now if I wanted just if I passed through we are going into the last block on the block we are invoking

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a different version of the list method which takes a filtering criteria.

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Now sometimes we want to just look for files having certain extension for example.

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So in our case we want to just look for the epic files within the demo project and we want to ignore

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all the other directories on any other files like that the extreme.

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We just want to look for only the big files.

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So there is a certain filtering criteria.

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So the method argument here is an interface it's called as a filename filter it's an interface and using

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that interface if you can implement that interface and you can specify your criteria.

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And here it is at the bottom after that name.

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After this class I would add this new class called it a pre-filter be a filter I need implements to

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find them filter which has this method called accept.

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So in the Axert I have the filtering criteria.

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I'm saying that if the current file that is passed here it and spitted git big dodgy .jpg are the caps

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aren't gaps Dundon are true.

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Otherwise you would read enough files.

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Ok so.

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So let me pass this class.

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The instance of ductless to the list knotter the list method vote in lieu of the accept method with

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each file within the current current directory each file and the directory name.

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OK so it would pass.

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Each of them to the X up method in this that has been defined in this class.

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Now if I had to run this as you can see it is just printing only dog OPG and Dot end caps and ignoring

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everything else in that directory.

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So that's how you would look for 500 or Chris.

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In any given electorate immediately appearing files on directories.

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So that's about it.

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That's how you would manipulate files on the system.

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OK you can use them for creating directories deleting directories or renaming files.

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Looking at the fire sun looking at the file properties and so on.

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So go ahead and you can find the updated class and the resources section and you can play around with

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it and look at other kinds of matters that are there in the final class and that's about it.

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Thank you and happy coding