So, listen, previously we had taken we took a look at the basic Janek's comments in this video, we'll
be learning some more comments.
So without any delay, let's get started.
So I have written all the comments I want to take in this video.
And the first thing I want to tell is there are three streams like LTT in which stands for Standard
Input, a studio, which means standard output to the air, which means standard error.
So this is input and a Russian.
What this actually does is it points to the our people, so generally we do the input to any application
via cable.
Right.
And this student points to the keyboard.
And this indicates that we are considering the input as a.
Input into the application, so you can think this as a file handler or file descriptor, which points
to the our keyboard data, so if we if I type Nikil now in my keyboard, then actually technical.
The standard output is represented by one, and if you use this, you don't want to in your comments,
then automatically the shuttle understands that you are going to ask the content of standard output,
of standard input, our standard error.
So the standard output points to the our screen desktop screen.
So if I paperny command, I look at the output and that or put these points to be pointed by this file
descriptor one.
And sometimes I get error because there is no command or there is no file, or if I get I can get so
many errors and that errors are appointed by the file descriptor two, which is standard error.
There is much confusion in standard output.
And don't worry, we'll discuss about these three in this scenario.
So let's get started.
As in previous review, I have said that let's call high.
And what I have done is I have said this greater than as a redirection operator.
It redirects output into the text, but it's.
Let's not be a unless.
So can I do more than another sample that is different?
So if I get lucky that I get the cadence of rock that the.
Which is high because the output of this government has been taken to the effect.
OK, that's not what I want to do, is I want to send the release of this command into the context of
it.
Now, what I can do is I can just put it before the great advanceable.
So what this means, I'm allergic to this comment.
And if there are any errors in executing this common.
I want to send that address into the property.
So that is too great a direct address to the relatives to know if I hit enter.
OK, there is no output, right?
Said Cataloger.
And as you can see, since there are no output, I had got this, too.
OK, now let's see a error message.
So there is no Nicole coming, right?
Obviously there is no Nicole Kidman in next.
So if I hit enter, it says that Nicole Kidman not form right now.
What I want to do is I will all put our reader to this, to tactics to fight.
So even when I read it to the people that I had got some output saying that coming out for because this
is not an output, this is the error error message, standard error message.
If I said get up, I get and I had no confidence in my taste of it because there is blank output and
that blank output has been stored in the last door and all the contents of this text file has been all
written.
So one way to store this is.
Using that the standard error descriptor for like that, then if I could enter, OK, there is nothing
displayed because our error has been related to the larger picture for catalog.
Know I have got the contents command, not form.
So this is my arithmetic and error message has been scored in the wrong five percent.
Nicoleta, I send it to cover.
There is also no legal document.
What I want to do is I want to open this address to the president and I see a contractor and my second
error has been generated because there is no nikil to command the systems and that error message has
been appended to make it so previously.
There is an governor for and know the contractor failure to command, not one.
So in this way, we can simply generate the error messages and store them in Rockford.
OK, now let's remove that no, what if I want to store both output and error in a text file?
So what you want to do is say a call.
Arcore, hello.
First, you need to send the output to the rock, rock, rock.
And afterwards, you need to do this.
You need to set the standard for this quarter and you need to return to the ampersand one.
See this ampersand one.
That is the output file descriptor.
That means the path to the output.
Where is the path to where the output is going?
So in our case, the output is going into the rock next fall.
And what I have done is I have said that I need my error messages to go in to the part where the output
is going.
So output is going into the lock that takes effect.
So after this command execution, my output of discovery will return control of the text file.
And if there are any error messages, those messages will also be buried in the rock, that 95 percent.
So there is no way to get a text file.
And I can say hello because there is no error messages.
I have got nothing in this text file.
I have got only the output, which is alcohol.
OK, now I want to tell you one more comment, that is final comment, so how you have in previous video
we had, take a look at how to find the comments using a look at comment if you pass it and filename,
we got the part of that folder.
So this fine also finds the part of the given file now.
But the syntax is very different.
What I want to do is find the space and the directory I want to search for.
I want to search my whole computer.
I just slash.
And I want to share a tape, I want to search for you minus type F stands for search for the fire tape
if that means I want to search for flight.
Not ready for that.
And I want to see the name and the name of the file.
I want to search, but not if I can.
OK, I stopped this using the Conservative Party, so there are so much finding going on.
OK, if I go to these are you you can see the find the organization and this permission because we are
normal user and we are finding the file in somebody's trees which are which we do not have access.
That's why we got the permission to it.
So these are these are our error messages.
So one way to get rid of these rumors is I want to say to which is the standard bearer for this.
I want to reiterate to the owner.
So this is a black hole.
So whatever contents we pass to this that they are not automatically within seconds, those contents
will get deleted.
So it's a black hole.
You can just throw in anything.
Some bits of that are gigabytes of data.
It just disappears because the background script for this bill and if any contents are in this, do
not treat those contents will get automatically deleted.
OK, now what we want to do is we are going to find from the rubber tree and the tape, I want to find
this file to file and the name of the file is wrong.
And I want that room.
I say just go to this day, which is a black hole.
I know.
If I had under.
So we have got this whole Nikitas and we did not get this large error, all because of the error has
been redirected to the.
So I want to see, since we got the, ah, Putin home, Nicky desktop rotblat.
This is one way to get rid of just.
So let me clear the screen, so I hope you have got understood, my father said less character.
Sorry.
There is also another way to append both output and error is we want to see a.
Hi, and what do you want to do is greater than the this are the first glimpse into this beautiful cat?
I have the height and the hello is the previous contents of the file.
And those contents have been all written that this is all you need to know about these new directions
and input output analysis.
No, I want to say the pipe comment.
I hope that this pipeline in the previous year.
But again, this is very important.
Let's, uh, let's let's see.
This is a file which is located government system.
I want to the paper to edit it less.
Now, the contents are the output of this command will be taken as important, this command less.
So, OK, I think we do not have the access.
OK.
We can pipe this into a less minor cell to long list everything, and if I put this into this, OK,
I have only one file.
If I have so many files, I can just scroll through these files.
So remember, this Bible is very important and will be using despite a lot of times and then we'll be
discussing this Speakman.
So if I take Petridis, I will get the contents of the directory.
It is tasteful.
So what if I want to see you and at the same time, I want to story to the.
So for that purpose, I can say to help out that.
So what this actually document does is it will print the output of this comment and also schools that
are put into the text file or any other.
So I have got the whole property external, so as you can see, the first Teckman will generate output
and then this comment that said, you know, if I get output, that I have got the same output stored
in the output.
So the first output that has been generated and then this one has been executed and the output of this
comment has been stored in this file.
So I think you have understood this.
And the next come you are going to see come in.
So I unless I get the wrong listing of these two files.
So don't worry about all this output.
I would explain in a separate video in the file permissions.
So let me get to know I had the condensers high.
Now I want to papercut.
And what I want to say is cut minus one.
So this command will just cut everything after the.
Or it just prints on exactly the character.
So my old world will be hit and if I said to the second character that I'll put up, so if I say three,
I get so using the comment, we can access only particular byte of data.
And if I see one two, I get the from one to two index.
So that is why this is the first quarter and this is the second character.
OK, now we can separate this text file as according to some fields.
Now if I say you have one, I get the height.
So basically this option.
That is that we need to divide the output as particular, have special exploit.
So if I say I have hollow world, then the fast food will be high and the second food will be hollow.
OK, I think you got confused.
OK, now let me explain this.
So we have got this last command and the first one says the total and the second line says that this
song Sunfire permissions and the total and also one which is now what I want to do is I want to separate
all these columns according to this piece.
So what I want to get is this total these are the first elements in these columns should be as first
filled.
And the are the second columns will be a second field and the third columns are stored.
So to get that, we need to use another option in the comment that is minus B, so D stands for Delimiter.
No, I want the suspense.
So what this Delimiter is doing is it will cut this output according to the space.
So there is a space between total and so again, for the total is one field and eight is one field.
And in the same way there are so many spaces in between this.
So this permeation, these contents are one field and this one is one field and this Nickie's one field
and this Nickie's another field.
Right.
Based upon the space command will do it, but it's going to come and doit's are the output into some
fields.
Now if I want to access the first field, I say you of one.
So as you can see from here, I got only Fosterville because the Delimiter space and it has donated
the contents according to this space.
So the first column or the first to feel is total.
And this one and this one, I say you have to get the eight one one.
So because that is the second column, you need to write it.
And if I say you have three, I get the null and the kikki because there is no third column or character
in the factually right.
If I say have three, I get the null, which is not.
And Nicky and Nicky, I say five.
I get that 390.
OK, I think there is some more space between that audit has been considered as if it has directly it
might get printed.
OK, that's horrible.
This could come in.
You can cut according to the delimiter.
And there is another command card had been there, so let's, uh, let's now I want to create a new
file.
Well, could frustrate me, see the contents of the.
So there is only one line, right?
So now what I want to do is I'll write some more lines of condensed and edited for clarity for a call.
Hello.
So in the same way, I wrote Hollowell.
So let me write some lines how to treat.
And Superman.
And I'm just opening this these into the text file Eidelman.
And parliament.
OK, these trends, I think these are enough, it will display the contents of log file.
Now we have got these rains and if you want to display the line numbers, you can see a lot of text
file and to display the right numbers, which we have the seven lines in our regular text file.
Now, what the head commander says it will take the first and number of friends and it will display.
And that's ahead minus for a number of lines.
If I say three and if I shared all the text file, I get the first three lines.
So this had to come in, will take the output from starting line and it will display up to this number
of lines.
Right.
So that current is opposite to this had come in the day command text line numbers from backwards.
That means from the last on what I said to longer text.
All right.
Get the last two lines so far and come off.
I get the violence in the text file.
And if I said rushed Minocin file I the violence of this text file.
So what I want to get only particular three, four lines.
So my aim is to get only the third and fourth.
Right now what I want to do is you want to generate from starting on what had Minocin to.
Four, because I want only three and four, right, the maximum number of lines that can be used for
and I will by this hour put into the.
So this output contains only the first four rings.
Hi.
Hello.
So in order to get only third and fourth rows, I just set a minister to.
Now, as you can see, I got a little late and for today, right now, what I have done is I'll just
recap once.
First I had to spend the first four lines and I have people that are put into the command so that every
command looks only at these four lines and in that four lines to display the two lines from the ending.
So the first four lines contains hi, hello, hello, hello three.
And these will be the input to the tail and the command always considers from the last.
And we said that continued two lines.
So from the last destruction and this is the last one I saw and had over three are being printed.
So in this way you can get a particular number of lines using the combination of identity comments.
So we can we can sort this using the command as a sort of text.
We know this contents of this text will get an order sorted in the setting of the alphabet.
So.
So there is hollow hit and the are the words which are being attended to one to one.
And then the second character has been checked.
E hello.
Hello.
Is this the hero is the least I mean the lowest tone in ascending order and the word and the word three
and then high.
So these are sorted according to the ascending order of the alphabet.
Right.
So you can also sort this in the reverse order by using minus R option.
As you can see, this is the exact opposite to this output, because it just was in the SAKURADA.
Now, what we want to do is you can pipe this into unique common.
So what this unique commando's is, when it chugs boo boo lines and the two lines are identical, it
will do more than one line.
So you see the unit coming later.
But the only property you need to do the unique command is that all should be in sorted order and sorted
out.
Only then you will create the model duplicates.
Right.
So the next command you want to do is the U.S. government.
The U.S. stands for work on.
It will count the words in the file and it will reduce the number of what?
So the first one is the line number.
It says that there are seven lines and the second one is the word no.
There are a number of words, mean seven.
There are seven words in the texture.
And how many bytes or characters are there in the text, what that means.
So in my log there are seven lines which you have seen and there are certain words that means each word
today and there are fifty nine.
But I'm interested in characters.
So what if I want to get only the only you say.
Lines, right?
No, I want to switch for my answer, and I got only the first line number, and if I tell you I regret
only the word count, it is also seven.
And if I say seat number of character, count it.
It shows us 15 it.
So these three are the important options for the U.S. command, which can work.
And the last one you'll be seeing in this video is Furqan so far far that says that as this fight is
the basic information about the fight you specified in the first argument.
So that's not we will be seeing the group come on.
Let's get log file.
Now, this group in Will matches the pattern and it will print only the line, the pattern matches.
So that's a group.
Now, I want to put in the lines, which has a lot in it.
So if I say group.
Hello, and if I hit enter now, I get the only alliance that has hello hello is the pattern we have
specified for the group and I have got only those three rings.
So if you if I want to ignore case, that means I want to search for Swan.
Hello.
And the capital.
Hello.
Then I want to specify this I, I switch and since we are lowercase alphabet's we have got to say I
want to put now put in words this matching that means show me the lines, accept the lines with the
Hollywood fight and now I get the lines other than the lines that contains the.
Hello.
This is the basic usage of the group in the future videos.
We will see some more examples of the group.
And also these are the basic comments.
And if there is any other comment I know Miss then will see that come out in that video.