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TechTranscript
00:03:30Hello, very good evening.
00:03:32Thanks for joining the session.
00:03:34Let me share my screen.
00:03:36In our last class, we discussed above the Linux directory structure and then file system we discussed.
00:03:54I have not yet got the host access.
00:03:59Let me get the host access.
00:04:02Just a moment.
00:04:14Just a moment.
00:04:14Just a moment.
00:04:14Hey, anyone join with my name?
00:04:19Those got the host access.
00:04:32I don't see the host access.
00:04:35Can you know, please give me the host access.
00:04:41Can you please give me the host access?
00:04:42Seems to be someone logged in with my name.
00:04:44They've got the host access.
00:04:47Just a moment.
00:04:56Just a moment.
00:04:57Just a moment.
00:04:58Just a moment.
00:04:59And then they got the host access.
00:05:00And then they got the host access.
00:05:00And then they got the host access.
00:05:01I was not able to see the host access.
00:05:03One moment.
00:05:04Just a moment.
00:05:05Just a moment.
00:05:06Let me get the host access.
00:05:07Just a moment.
00:05:08Just a moment.
00:05:09Let me share my screen.
00:05:12Yes.
00:05:13So, let us go to the DevOps tool and let me open the class nodes and Linux class nodes.
00:05:31here we are discussing about the Linux file system isn't it so this is what we discussed
00:05:46so as part of this Linux file system understanding the directory structure and all
00:05:53we discussed we have completed discussion till this var one and then run also we completed
00:06:00so rest is the mount and then media so these two are like to mount external file system this mnt4
00:06:12and then media for like a disc writing cd reading dvds reading for that the media will be useful
00:06:22however let me log into let me log into
00:06:31let me log into
00:06:32aws management console let me log into aws management console
00:06:41just check aws management console yes let me log in
00:07:08okay so i was logged in go to ec2 machine
00:07:26issue to ec2 services nothing is running go to the instances let me start our instance
00:07:37our instance is linux practice 7 pm instance
00:07:46unfortunately its key is in my other mission
00:07:49linux 7 pm it's a key is in my other mission
00:07:56let me start the instance
00:08:07the two options the two options i have now i'm on some i'm on different laptop my new laptop don't have
00:08:18this key and we don't i mean we don't have the provision to download this key again
00:08:26because already one time i download it however let it start let it start
00:08:36yes it is started now just let me copy the ip address
00:08:51public ip address let me create the session and this is what the
00:09:00ip address just let me use the username as john because i am not able to retrieve the certificate back
00:09:12so let me change the session name as linux 7 pm
00:09:22just click on ok yeah no authentication methods are available for this user so i was not able to
00:09:34login because the key whatever the key we used so far that key is an another mission so i am not able
00:09:43to download the key again on this mission what i will do is let me create new mission
00:09:50one new mission one new mission let me quickly launch okay one new mission let me quickly launch
00:09:57to do that what we have to do go to launch instances launch instances this is the new dashboard
00:10:08and there is a old experience also we have we can so new dashboard launched instances give the name for
00:10:15the instance linux 7 pm machine linux 7 pm machine and number of instances or one then what kind of instances we want i want ubuntu
00:10:34and ubuntu we have the 22 but i don't want to use 22 i want to go with the 20.04 ld ld yes and
00:10:50instance type is micro is good enough because one vcpu one gb memory and moreover free tire eligible
00:10:58so 750 hours per month so 750 hours per month i will get as free so that is the reason let me go with this one
00:11:07so create a new key pair key pair name is linux 7 pm machine private key this is my key name and we know
00:11:22key pair type is rsa rsa encrypted private and then public key pair rsa is a public key signature
00:11:32and a private key file format is pemfoil and then ppk let me download the pemfoil create a new key pair
00:11:41now new key pair is downloaded so with this information let let me launch the instance
00:11:47and uh what i will do is mean the time instance launched let me go here and then create one directory
00:12:02my trainings in this my trainings let me create one more directory easy to
00:12:11key pairs easy to key pairs easy to key pairs let me go to here go to easy to key pairs
00:12:26yes so i was copied the easy to key pair to some other location
00:12:31fine fine fine now let me go to the instance which is started yes this is running now we got this public
00:12:44ip address go here linux 7 pm machine edit the session paste the new public ip address upload the private key
00:12:57private key private key is i just have copied many pasted in the t my trainings easy to key pairs this is
00:13:07the key pair right just let me change the username now ubuntu because i know the key pair
00:13:16yes now if i just press r then we will be able to see the connection
00:13:23perfect now the connection is established so as the connection established if you can see who i am just
00:13:45printing who am i in just showing you are ubuntu perfect now what we are discussing we are discussing
00:13:57about this linux directory structure isn't it so slash is the parent directory we completed all these things
00:14:06and the only two left over directories are media and then mount so media and then mount this also let me
00:14:17go back and then login as a root user and let me go to this media see nothing empty and then opt sorry media
00:14:27nothing and then mount also nothing don't have anything like opt media and then mount also
00:14:36don't have any data in it so when we put a cd or the dvd like laptop have the cd rom right dvd rom as well
00:14:50so when we put the cd or dvd the data will be mounted in this mount directory right so the data will be there in the mount directory
00:15:01so for cd roams uh to mount external file system sorry slash media contains the cd rom mounts and then mnt mnt
00:15:14mnt meaning mount to mount external file system that means what example network file system if you want to keep our files in some other network then we can mount that network on the mnt
00:15:29network on the mnt so these directories we don't use usually so the most frequently used directories are
00:15:39the most frequently used directories are let me note it down the most frequently used directories
00:15:48just let me open the notepad hope you are able to see my screen right just let me change the
00:16:04appearance
00:16:09just let me change the appearance of this one the editor
00:16:13text editor
00:16:20you can change the color actually
00:16:24just let me change the appearance of this editor text editor formatting
00:16:32let me search here
00:16:33color customization
00:16:42text editor
00:16:43text editor
00:16:45appearance
00:16:47yes so color theme not dark i want
00:16:51light
00:16:53yes
00:16:54this color theme is good
00:16:56then this also i want to light
00:16:58this is also about light
00:17:04fine so looks good now
00:17:09with this uh light contrast
00:17:13okay however now let me open a new text file
00:17:18perfect perfect date is the today's date date date is 20 june
00:17:312022
00:17:33topic is the continuation of linux
00:17:37directories
00:17:38and file system so today let us complete this one
00:17:45so the most commonly
00:17:49most commonly used directories
00:17:54in our real time most commonly used directories are
00:17:58most commonly
00:18:00usr slash bin
00:18:03because when we install any software it will be installed here
00:18:12in the usr pin
00:18:15and then next is
00:18:19slash usr slash sp
00:18:23and then the slash var directory most frequently used
00:18:33and then slash etc directory
00:18:37and then
00:18:39slash opt directory
00:18:42so these are all the directories we most commonly used
00:18:49if you know the meaning of these five directories
00:18:53that is good enough
00:18:57am i addable folks
00:18:59someone said my voice is dull
00:19:02yes you're sorry
00:19:05so the most commonly used directories are
00:19:09user bin
00:19:10user s bin
00:19:12slash var
00:19:13slash etc
00:19:15slash opt
00:19:17so other directories are also there for us
00:19:20but we may
00:19:22one more is slash home
00:19:24how we will forget that
00:19:27we should not
00:19:28so home directory
00:19:29so these are all the directories
00:19:32however we have some other directories as well
00:19:35but most frequently we will work with this six directories only
00:19:41so you have to know the meaning of these six directories first
00:19:46i believe we already have discussed so many times
00:19:50right about these directories
00:19:52so again let me showcase you the importance of this one
00:19:57let's say docker install just in case docker install ubuntu
00:20:02i'm just clicking on here
00:20:05scroll down
00:20:05scroll down
00:20:11what is happening see this
00:20:13there is one directory creating in the etc
00:20:17and then storing the files
00:20:20and also if you can see
00:20:25this is installing docker c docker cli
00:20:29so these are installing
00:20:32so whatever those installed right
00:20:34those will go to the slash usr slash bin directory
00:20:42sometimes explicitly we need to move them to the directory for example
00:20:47docker-compose install ubuntu
00:20:52if i click on this
00:20:54let me go to this install docker compose and let me use this
00:21:00distillation site
00:21:02so whatever it is
00:21:04just let me click on this one
00:21:06distillation site
00:21:08so the steps were clearly given
00:21:11now see what is happening
00:21:13we are downloading the docker compose and moving to usr local bin directory
00:21:20usr local bin directory
00:21:23and then the changing the permissions
00:21:26usr local bin directory
00:21:28right and then checking the docker compose version
00:21:33so this directory usr slash bin or usr slash local slash bin
00:21:39if we can go to this uh cd space slash usr unix shared resource directory this year
00:21:48so as it is a shared resource directory
00:21:51so either we can keep the softwares in the bin
00:21:57or someone will download some softwares will download into the lib
00:22:01some will go to the local some will go to share few will go to sbin
00:22:07right so by default they will be go to different different directories based on
00:22:13the uh the the directory structure mentioned in their particular software
00:22:19otherwise we can also download and then move it to these respective locations basically
00:22:24right so that is the reason we need to understand these directories very well
00:22:29i hope you are clear with all these directories
00:22:33var etc so when you download the docker or postway or mysql or any server or any application
00:22:40its logs will be maintained mail will be maintained spoof mail mail will be maintained
00:22:46all will be maintained in this var directory
00:22:48so these are the most commonly used directories that we have now we completed the directory structure
00:22:58we understood the meaning of each and every directory now let us see the navigation commands
00:23:05to navigate from one directory to another directory so when navigating a linux file system
00:23:12there are a few important commands change directory present working directory and then list directory
00:23:22so we already have seen these things so cd stands for the change directory it is the primary command for
00:23:30moving you around the file system meaning what is my present of pwd for print working directory
00:23:38so now i am in the usr so i want to move to another directory let's say cd space slash root
00:23:47now i am here so lsfnl yes and now back to root pwd i mean now root directory which one we used cd we used
00:23:57for changing one directory to another directory then pwd stands for print working directory it will tells
00:24:05us where are we what is our current location in the directory structure is as we very well know ls
00:24:14ls transfer list we have seen various combinations of the ls commands like ls-l ls-lr t ls-r t ls-r ls-r t
00:24:26all those things we have seen for example see usual this is most frequent used commands ls fnl or ls right or ls fn a so most frequently used command this is ls command
00:24:41okay now let us understand so we we will understand now the navigation file system so to move from one
00:24:49directory to another directory to another directory we can use the cd and then to know the current
00:24:54directory where are we use pwd print working directory and to see the files in that current
00:25:02working directory use the ls command so this is navigation navigating file system next is the file
00:25:09system paths we have the two paths available the one is the absolute path and the second one is the
00:25:18relative path so one is the absolute path and second one is the relative path so we need to understand
00:25:26this one actually what is absolute path and then what is relative point fine so absolute path an absolute path
00:25:35always begins with the slash absolute path always begins with slash this indicates that the path starts
00:25:45at the root directory at the root directory if we can go here what is here slash what is here slash that
00:25:54means what that is the absolute directory so absolute absolute path it is right so starts with this slash
00:26:06indicates that the path starts as the root directory so an example of an absolute path is
00:26:13cd space cd space slash var slash log hdp slash meaning always we are starting from the root directory
00:26:22that is the meaning of slash it's always we are starting from the root directory that is the meaning of this slash
00:26:29so if we can go here okay so let me even go to here where are we i am at this location so from this location
00:26:43if you would like to go to from this location if you would like to go to any other directory here now we are here
00:26:53from this location to go to any other this directories what we will do cd and then what we have to do
00:27:02first we need to mention where are we and then in which directory we have to go see opt first where are we
00:27:11and then which directory we want to go so that is what is nothing but the absolute path
00:27:19right so now the relative path a relative path does not begin with a slash
00:27:25it identifies a location relative to our current position
00:27:36what does it mean now i was changed to pwd
00:27:42right now i'm in the pwd in pwd let's say let me create one directory
00:27:51now if you can see i have the demo is one directory so demo is inside the opt now if you want to go to
00:27:58demo i was not given slash just i was given demo slash now i entered into the demo so inside the demo
00:28:10let me create the linux demo one directory
00:28:15now ls fnl linux demo one so cd space linux demo one now i entered to linux demo one now
00:28:26see the pwd now cd space slash cd space slash i'm in opt now if i can type demo see this
00:28:37what did you understand now when you when we are inside one directory when we were already inside one
00:28:47directory from that directory if you want to navigate to any any other directories inside that directory
00:28:56only right from for example i'm in the opt directory inside the opt i have a demo directory
00:29:06inside the demo i have a linux demo one directory
00:29:10so to go to demo directory or linux demo directory which is inside the opt directory we have to use what
00:29:19this relative path right okay now let us go here i am in the opt demo and then the linux demo directory
00:29:32from here i want to go to home directory then if i give home hit is it coming no if i give slash is it coming
00:29:41yes that means what if you want to go to any of the directory under the parent directory then we should
00:29:51have to definitely append slash that is called absolute path root directory parent directory path
00:29:59so an absolute path always begins with the slash absolute path we have to give to go
00:30:05to any of the directory to any of the directory which is under the root directory or the parent directory
00:30:11called slash any directory you can say for example i'm here i want to go to var see i never get var if
00:30:20i type var va i never get it but when i say slash then i can get it go inside the var now p w t i'm in the var
00:30:31directory so i can see the var directory hope you now you got the difference between the absolute
00:30:38directory and then the absolute path and then the relative path right so what is the difference between
00:30:43the absolute path and then relative path absolute path means okay let me write it actually okay so that
00:30:51you will easily understand when i am writing absolute path absolute path absolute path will be always
00:31:06represents with slash
00:31:11if we want to go to any directory
00:31:17if you want to go to any directory if you want to go to any directory under the
00:31:24parent directory that is a slash
00:31:30then we have to use the absolute path
00:31:36path for example we want to go to slash home or want to go to slash opd or want to go to slash etc
00:31:52this is absolute path and what is relative path
00:31:57relative path so relative path will always represents always represents the directory or
00:32:12or file inside the inside the inside the another directory
00:32:22another directory for example
00:32:27for example we have a directory called opd right under which
00:32:38another directory created called demo right and also inside the directory demo
00:32:51another directory created called
00:32:58linux underscore demo one
00:33:03now now
00:33:07slashed opt will represents absolute path
00:33:13after after slash opt when we when we are at the slash opt then we have to give cd demo
00:33:26so this is called the relative path
00:33:31this is called relative path now once after we were inside this demos demo directory
00:33:39and cd space linux underscore demo one so this is what relative path
00:33:49got it what is absolute path now and then what is the relative path so relative path always not
00:33:57starts with the slash right so that is the relative path so by this way we were done with
00:34:04this linux directory structure and then the file file and then directory structure so there were a lot of
00:34:12other directories as well we were not at looked into it not required actually so as i mentioned here
00:34:19here these are the six directories we mostly use in our day-to-day life we have to get a more clarity
00:34:26a more picture on these six directories that is good enough however now let us go to our next topic
00:34:36that is the creating files and then directories so any questions are we good with this linux file system
00:34:45structure linux directory structure and then file system any questions are we good any questions shall
00:34:53we move to the next topic i believe you are clear right
00:34:59great so no answer i am taking as a consent to go to the next topic so the next topic is creating the
00:35:09the creating the directories and then creating the files
00:35:18so usually we can use the following commands to list the directory ls ls-l ls-lrt right so we know what
00:35:29is the meaning of this lrt long list long list reverse long list reverse time right timely reverse so the
00:35:38we know we have seen about this command in our earlier sessions and we even know what is the meaning
00:35:45of hyphen hyphen meaning a file d meaning a directory so in linux linux file system we have seven types of
00:35:54files in the linux so what are those seven types of files the seven types of files is regular file
00:36:05directory directory link special file or device file s for socket p for named pipe and b for block device
00:36:20so these are seven symbols we have meaning for seven different files in the linux remember
00:36:29everything in the linux is a file system including the command prompt is also a file system everything
00:36:38is a file system right so that is the reason we have the seven file types in the linux
00:36:48for example uh if you can see here
00:36:51what did you understand from this one d is there d for what directory right so when anything starts
00:37:02with the d it is a directory then l is there l l for what link so if you can see here there is a
00:37:12there is a soft link is here and l is here l for what again a link soft link is here about the soft link
00:37:23and then hard link i will discuss in our coming up sessions and uh sorry my session expired let me
00:37:34re-login again fine so clear everything now ls-l nothing is here let me go to slash uh etc and ls-l you can see a lot
00:37:49here you can see a lot here let us starts from the beginning say d for a directory hi hyphen for the file
00:38:00and then next is what uh yes here l for the link right and then the l for the link yeah mostly link
00:38:12till link is here so let us go to one another directory that is slash device so ls-l in this device
00:38:24mostly you will see what the files are starting with the c isn't it c meaning what special file or a
00:38:33device file see most of the files you will starts with the you will starts with the c most of the
00:38:41files you can see which are starting with the c c these meaning device files these are for example
00:38:50if you can see the cpu dma latency and uh there is uh again btrf auto fs so these are all the file system
00:39:03device file system related things and a few are starting with the b b for what block device
00:39:12so loop zero so there were loop seven so these are the block devices which are belongs to the group
00:39:22called disk user root but the group is the disk there is a group created called disk what is user
00:39:31what is group we'll discuss in our coming up sessions but the types of file systems is what we are now
00:39:37discussing again c c for what device file b b for what a block file block device so this is a device
00:39:48look for this device look for a device i don't think we'll be able to go there just let me cd and cd let
00:39:57me use this block device uh xvda so xvda uh no it is not a directory it is not a regular directory to
00:40:12go and then see actually right it is a file so maybe if we would like to see the content of it
00:40:19it so permission denied let me log in as a root user and then again let me go to etc and then clear
00:40:29everything then ls-l right now i want to see sorry we are not in etc right so i want to go to slash
00:40:39device directory so cd ls-l right so would like to cat the block device called
00:40:47um so there is a block device yes loop zero so let us see the cat loop zero something is here control c
00:41:03control c did you see that some some device specific file it is we we are not able to even understand
00:41:10what it is right so ls-l correct so like that we have some block device files even i don't know the
00:41:20meaning of those block device files honestly because i never get a chance to work with them
00:41:26but so we have to know actually so right so b is the black device and then c for the special file or the
00:41:35device file right and we can see socket so in order to see this socket types of files which directory we
00:41:42have to go in order to see the file type socket any idea any idea which directory i can go proc a run
00:41:56or root any idea which directory i have to go to see the um files of type socket any expectation just guess
00:42:08let me go to cd space process directly lsf and l do we have any files which are starting with the yes
00:42:18no we don't have any files starting with s here let me go to run type i meaning cd space slash run so we are
00:42:32inside right so cd cd space slash run ls-l any file that is starting with the yes socket yes there is one file
00:42:48which is starting starting with the socket acp id dot socket so what is what is the socket actually
00:42:56where we will use the socket socket meaning if there is a for example in streaming we can use these
00:43:03sockets uh uh familiarly what what is the meaning of it actually um for example let me go here draw dot i o
00:43:19let me open this draw dot i would i would like to draw something decide later
00:43:27go here go here create page right so there is uh there is one media right there is one media
00:43:46maybe we can say it as the media player
00:43:55right so what we will use to listen some songs and all we will use this earphones
00:44:07how these earphones will be plugged in so earphones will be plugged in through some wire
00:44:13then continuously the media will be flown to this earphones so the media player have one socket
00:44:21here into that socket we will inject the wire so that the media will be transformed to this device
00:44:31so socket meaning what in the client server architecture usually in the client server architecture
00:44:39in the client server architecture if you want to flow some data if you want to flow some data
00:44:48if you want to flow some data from the source to the destinations so the from the source to
00:44:57the destinations then what we will do we can use this socket programming sockets we can use
00:45:04there are other ways also to float the data from one device to another device so socket is what you know
00:45:13udp communication datagram packets the media file the media will be or the live streaming will be sent to
00:45:23different different screens right as a pockets network pockets network pockets so that is what the udp
00:45:31communication so there we will use the socket so that means what these clients will connect once to this
00:45:39source then keep on get the data from the source so that is the socket so in our jenkins architecture as
00:45:47well we will use our jenkins master and then we will use our jenkins workers worker one worker two
00:45:57so this worker one worker two will connect with this master via socket programming via socket program
00:46:08we will connect to this master there are two options actually one is the tcp communication second one is
00:46:14the udp communication if it is udp then we definitely will use it as a socket but here mostly tcp and the
00:46:21udp both are possible so we will use the tcp communication tcp is not circuit again but i am
00:46:26saying socket communication is possible plus the agent based communication http communication is possible
00:46:36http communication is the requested response data of our met not pockets right so that is what the
00:46:45socket meaning our docker also have a socket so usually anything anything if we would like to run
00:46:54continuously behind the system for example docker we want to run permanent we want to run continuously
00:47:00in our mission when the mission will start the docker will start when the mission will stop the docker
00:47:05will stop and the docker also will be run as one socket right so that is the meaning of the sockets
00:47:13so this is the socket files so these are the seven types of the files that we have in the linux
00:47:22right so c meaning what special file or device if we attach a keyboard or cpu or memory like anything
00:47:30attaching to the system also create as a file starts with c right so i was attached my mouse
00:47:38to this uh to this uh my laptop so if if my laptop is a linux based system then definitely i should have
00:47:51see one file created in the c yeah i i should have see a file created with the uh which is starting with c
00:47:59c isn't it so that is about the linux file types now how do we create a file and then directories
00:48:11so we can create the files in linux using the following three ways one is the touch second one is the cp
00:48:19and third one is the vi editor so using these three ways we can create a file so let us try to create
00:48:32file using the touch command
00:48:36file so if you can see here in this uh screenshot i have used a touch command see this
00:48:46touch command so touch command is used to create any number of files using a single command like this
00:48:53so touch linux introduction one linux introduction two linux introduction three like this any number of
00:49:02files we can create using the touch right so cat is using to view the file data cat is used to
00:49:14view the file data
00:49:26one minute
00:49:31fine so let me go and then create the files using this touch command
00:49:49i am reading through the mail i got actually but that's okay fine so let us go to the cd space slash opt
00:49:56directory which we will play left and right in this opt directory but so now what we will do is let us
00:50:05create the file touch touch linux underscore intro introduction underscore or linux introduction is one file
00:50:20so let me login as a root user and then go to the opt directory and then create the file so touch space
00:50:32linux underscore introduction
00:50:36now ls-l see linux introduction file is created with the zero bytes with the zero bytes that means what
00:50:47using that touch command we are creating the files which don't have any data so empty files
00:50:55we can create so linux introduction nothing is there no no content is displayed right
00:51:04now what i can do is
00:51:07these touch command using touch command we can create the empty empty files first of all is it file or
00:51:13directory just let me just let me know is it's file or directory which is a file not directory
00:51:21right so and using cat it created sorry using the touch is created so zero bytes it is so using touch we
00:51:29can create the files at a time for example linux introduction then linux directory directory
00:51:38directory structure and then the linux basic commands linux basic commands and then linux
00:51:53files linux files directories creation so what are these these are all the files i'm creating at a time
00:52:02in using a single command now lsf and l so these are all the files created for us linux basic commands
00:52:09linux directory structure linux directory structures creation right so linux introduction so these are all
00:52:19the these are all the files the these are all the files created now if i want to see the data inside of this one
00:52:28linux basic commands no we are not able to see because we don't have the anything
00:52:35if we give anything echo for example welcome to linux
00:52:41linux then let me use the linux basic commands or linux introduction
00:52:53linux introduction now lsf and l right so cat linux introduction see welcome to linux what i did
00:53:05i have created i have created an empty file into that empty file and given some data right this this
00:53:15greater than symbol for what actually whatever the data we have that data is writing into this linux
00:53:23introduction file right so this is about the touch command
00:53:30so touch command is used to touch command is used to write the data in touch command is used to create
00:53:38the empty files using touch command we can create any number of empty files
00:53:43sir i have a question what is the use of uh empty file why you used to create a vision touch no just we
00:53:51can create a file later on time we can feed the data into the file right usually usually
00:53:59we want to the purpose of the file is to keep something inside in it isn't it so yeah so now we
00:54:06have learned how to create the files using the touch command now next what we will see we will open
00:54:14your file how to open your file using the vi editor and now we will see now going forward
00:54:18okay sir go ahead go ahead go ahead please cat also is used to create a file sir i don't think actually
00:54:29but let us see yes sir uh actually i learned it because you by using redirection options we can create
00:54:36files by using cat command also cat command is used to create non-empty files i'm just checking this
00:54:44cat i don't see cat uh we are used to read the data basically no no no sir actually cat also used to
00:54:51create non-empty files interactively data can enter that i'm just checking if you don't mind
00:54:58cat hyphen f5-1g outputs no we by using uh input redirection sir can i tell you yeah yeah
00:55:10cat greater than cat space greater than a.txt then enter you can type something first line and enter
00:55:22second line uh this is what you know input redirection this is this is input redirection actually
00:55:40actually today is my first class yeah actually i learned linux through the ruka sir okay okay fine
00:55:48so this is the input redirection so input output redirections we'll discuss maybe later okay but
00:55:54by using cat also we can create anonymity first am i correct uh i can say using input redirection
00:56:01we can create the files input reductions and output direction these are redirecting right
00:56:06so this cat is what you know we opened a file so we opened a file and in the opened file we are
00:56:14uh giving some input instruction no no actually we didn't create a.txt previously
00:56:24cat uh greater than a.txt then automatically a.txt will create and then uh command line prompt asking
00:56:31us to to enter some data correct correct why how it is feeding the data first of all cat is opening a
00:56:40file yes the file yes the file is not cat is to open the file see this the meaning of the cat is what
00:56:47actually so concatenate cat you see concatenate files to standard output yes yes right so with no file
00:56:56or when file is a hyphen read a standard input yes yes correct yes so what we can do now we can open the
00:57:07file first into that file till it's eof end of the file yes yes write the data got it yes like vi editor
00:57:18also correct exactly correct exactly correct and one thing uh i would like to say touch command is also
00:57:26used to change the timestamp that's one is very important to us without a touch is a user for creating
00:57:33non-emptive files at the same time touch is used to create to change the timestamp
00:57:39yeah fine that's the important thing in my life okay fine sorry sorry to interrupt no problem so so we
00:57:48have learned how to create the files using the touch command now yes yes yes then what then what is the
00:57:56next we can use the cp so cp command also used to create another file from an existing file this is
00:58:07also copy copy of the content from one folder another folder exactly correct correct cp means yes yes so
00:58:14this command is used to create another file from the existing file if the file contains the data it will
00:58:19be copied the file don't contains anything meaning whatever the file that contains by using cp command
00:58:26we can we can't create the new file correct so cp let me copy linux linux basic commands to linux basic
00:58:40commands this is very important command we will use because in real time if we want to edit any file
00:58:47for example we have one server in server we want to edit any file first we need to take a backup of it
00:58:54so in order to take the backup of it so we will copy the original file into some other file for example
00:59:02now i would like to modify this linux basic commands file first i want to take a backup of it so let me take
00:59:09a backup like this original data bckp something like you can give anything now what will happen it's a
00:59:16backup will be created so what's the backup copies the one one one further correct so exactly so
00:59:26whatever the content is here that content will be as it is copied to this backup so now it is the backup
00:59:32of the existing file now we can happily edit this existing file so if something went wrong in the edit
00:59:38no problem we have a backup what we can duplicate file means so we have a backup then we can extract
00:59:46the content from that backup even so that is the copy command we used okay so that's all for today folks
00:59:55and uh tomorrow so i have some queries today is my first class okay good how many days you will teach
01:00:03the linux so probably this week uh we will complete and then start next week we will start the git repository
01:00:12do you teach shell scripting also those are required actually we we will see the shell scripting as well
01:00:19but shell scripting what you know i want to teach along with the use cases and then the work what we are
01:00:26using for example if we can go and then see the jenkins we used to write two to three cases we used to write
01:00:34the shell scripts actually i learned linux and shell scripting and also git also through durga sir
01:00:42but i want to learn jenkins and other tools yeah that might take little time maybe because you know
01:00:50first this linux maybe this week the basic linux commands and all basic introduction of the shell
01:00:56scripting and all will be completed so early in the next week uh we will start the git repository that
01:01:01maybe take two to three days then we will go to the jenkins sir may i get the previous recordings of
01:01:08your process yeah yeah i am just already i learned linux that's the reason i am asking to you please
01:01:15give me the previous batch recordings yeah it will be way more beneficial for us to put the resume in
01:01:22short time correct correct so ask our team they will give you i already asked to the back-end team but
01:01:29they don't but they say said like there is no previous batch recordings 8 pm is going on 8 pm batch
01:01:38going on actually you also suggest you also suggest to that team then i then i get the
01:01:47previous dates recording okay fine i'll suggest okay guys i'm stopping my screen sharing and then
01:01:53uh uh see you tomorrow at the same time and also and also give the last week recordings then i'll watch
01:01:59that yeah yeah so recordings and all will be given by the back-end team we'll do one thing uh just to
01:02:06give me uh just mail me please give me your mail id yeah yeah i'm just typing so just talk to sorry for
01:02:14the devices actually i'll just send an email to me i'll talk to them please give me your mail id yeah
01:02:20yeah yeah just copy it okay in the chat box now yeah yeah thank you thank you very much thank you
01:02:26yes thank you guys thank you so much and see you tomorrow at the same time
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