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| -rw-r--r-- | ult/ult_2/script.rst | 301 |
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diff --git a/ult/ult_2/script.rst b/ult/ult_2/script.rst index 21db359..6c866da 100644 --- a/ult/ult_2/script.rst +++ b/ult/ult_2/script.rst @@ -3,16 +3,15 @@ .. At the end of this tutorial, you will be able to: - .. 1. Copy files from one location to another. - .. 2. Remove files and directories. - .. 3. Change permissions and ownership of files. - .. 4. Navigate through directories and files. + .. 1. Remove files and directories. + .. 2. Copy files from one location to another. + .. 3. Move files and directories. + .. 4. Know the Linux File Hierarchy .. Prerequisites .. ------------- -.. 1. Using Linux tools - Part 1 - +.. 1. Getting started with Linux Script ------ @@ -25,7 +24,7 @@ team along with the logo of MHRD }}} .. R1 Hello friends and Welcome to the tutorial on -'Using linux tools - Part 2'. +'Basic File handling'. .. L2 @@ -35,10 +34,10 @@ Hello friends and Welcome to the tutorial on At the end of this tutorial, you will be able to, - 1. Copy files from one location to another. - #. Remove files and directories. - #. Change permissions and ownership of files. - #. Navigate through directories and files. + 1. Remove files and directories. + #. Copy files from one location to another. + #. Move files and directories. + #. Know the Linux File Hierarchy .. L3 @@ -47,7 +46,7 @@ At the end of this tutorial, you will be able to, .. R3 Before beginning this tutorial,we would suggest you to complete the -tutorial on "Using Linux tools - Part 1". +tutorial on "Getting started with Linux". .. R4 @@ -59,9 +58,12 @@ Here's example to remove a file named "foo" from the directory "sdes", .. L4 +{{{ Copy the folder /sdes to your home folder }}} +{{{ Open the terminal }}} {{{ Navigate to /home/user/sdes/ }}} :: + ls rm foo ls @@ -101,6 +103,7 @@ how would we do it? pwd cp linux-tools/scripts/foo linux-tools/ + ls linux-tools/ .. R8 @@ -112,10 +115,11 @@ target location,as, :: cp linux-tools/scripts/foo linux-tools/bar + ls linux-tools/ .. R9 -This copies the file ``foo`` to the new location, but with the new name, +A copy the file ``foo`` is created, but with the new name, ``bar``. But, what would have happened if we had a file named ``bar`` already at the @@ -149,7 +153,8 @@ Now, let's try to copy the directory ``sdes`` to a new directory called .. L11 :: - cd /home/user + cd + pwd cp -i sdes course .. R12 @@ -175,22 +180,22 @@ file. Instead, you can make use of only one command which can do this task at one go. The ``mv`` command can move files or directories. It also takes the ``-i`` option to prompt before overwriting. -.. L14 +.. L13 :: cd /home/user mv -i sdes/ course/ -.. R15 +.. R14 Let us understand what exactly happened when we used the ``mv`` command -.. L15 +.. L14 :: ls course -.. R16 +.. R15 We can see that the ``sdes`` directory has been inserted as sub-directory of the ``course`` directory. The move command doesn't over-write @@ -199,12 +204,13 @@ directories, but the ``-i`` option is useful when moving files around. A common way to rename files (or directories), is to copy a file (or a directory) to the same location, with a new name. -.. L16 +.. L15 :: mv sdes/linux-tools sdes/linux + ls sdes -.. R17 +.. R16 It renames the ``linux-tools`` directory to just ``linux`` @@ -213,279 +219,144 @@ within the ``/home/`` directory, but other than that there are many other directories too. Let us take this opportunity to understand a few things about the linux file hierarchy and file permissions. -.. L17 +.. L16 :: cd / {{{ Switch to slide, Linux File Hierarchy }}} -.. R18 +.. R17 The ``/`` directory is called the root directory. All the files and directories, (even if they are on different physical devices) appear as sub-directories of the root directory. -.. L18 +.. L17 {{{ Switch to terminal }}} :: ls -.. R19 +.. R18 You can see the various directories present at the top most level. -.. L19 +.. L18 {{{ Pause for sometime and then continue }}} -.. R20 +.. R19 For more information, it is recommended that you look at the ``man`` page of ``hier``. -.. L20 +.. L19 :: man hier {{{ Pause for sometime and then hit q }}} -.. R21 - -Let us now look at file permissions. Linux is a multi-user environment and -allows users to set permissions to their files to allow only a set of -people to read or write it. Similarly, it is not "safe" to allow system -files to be edited by any user. All this access control is possible in -Linux. -To start, in the root directory, say, +.. L20 .. L21 -:: - - ls -l -.. R22 - -You again get a list of all the sub-directories, but this time with a lot -of additional information. Let us try and understand what this output says -Consider the first line of the output, - -.. L22 - -{{{ Highlight the required portions accordingly while narrating }}} - -.. R23 - -The first column denotes the type and the access permissions of the file. -The second is the number of links. The third and fourth are the owner and -group of the file. The next field is the size of the file in bytes. The -next field is the date and time of modification and the last column is the -file name. -We shall look at the permissions of the file now, ie., the first column of -the output. - -The first character in the first column specifies, whether the item is a -file or a directory. Files have a ``-`` as the first character and -directories have a ``d``. - -The next 9 characters define the access permissions of the file. Before -looking at it, we need to briefly study groups and users and ownership. - -We already know what the first character in the first column (in the output -of ``ls -l``) is for. The rest of the 9 characters are actually sets of 3 -characters of each. The first set of 3 characters defines the permissions -of the user, the next 3 is for the group and the last three is for others. -Based on the values of these characters, access is provided or denied to -files, to each of the users. - -So, what does each of the three characters stand for? Let's suppose we are -looking at the set, corresponding to the permissions of the user. In the -three characters, the first character can either be an ``r`` or a ``-``. -Which means, the user can either have the permissions to read the file or -not. If the character is ``r``, then the user has the permissions to read -the file, else not. Similarly, ``w`` stands for write permissions and -decides whether the user is allowed to write to the file. ``x`` stands for -execute permissions. You cannot execute a file, if you do not have the -permissions to execute it. - -Similarly, the next set of characters decides the same permissions for the -members of the group, that the file is associated with. The last set of -characters defines these permissions for the users, who are neither owners -of the file nor in the group, with which the file is associated. - -Now, it's not as if these permissions cannot be changed. If you are the -owner of a file, you can change the permissions of a file, using the -``chmod`` command. - -.. L23 - -.. R24 - -Let's say, we wish to give the execute permissions for a file, to both the -user and the group, how do we go about doing it? To be more explicit, given -a file ``foo.sh``, with the permissions flags as ``-rw-r--r--``, change it -to ``-rwxr-xr--``. - -The following command does it for us, +{{{ Show summary slide }}} -.. L24 -:: +.. R21 - chmod ug+x foo.sh - ls -l foo.sh +This brings us to the end of the tutorial.In this tutorial, we have learnt to, -.. R25 + 1. Remove files using ``rm`` command. + #. Copy and move files from one location to another, using the ``cp`` + and ``mv`` commands respectively. + #. Learnt the file system hierarchy of Linux. -As you can see, the permissions have been set to the required value. But -what did we exactly do? Let us try and understand. +.. L22 -.. L25 +{{{ Show self assessment questions slide }}} -{{{ Switch to slide,Symbolic modes }}} +.. R22 -.. R26 +Here are some self assessment questions for you to solve -In the command, the parameter ``ug+x`` is the mode parameter to the -``chmod`` command. It specifies the changes that need to be made to the -permissions of the file ``foo.sh``. -The ``u`` and ``g`` stand for the user and group, respectively. The ``x`` -stands for the execute permission and ``+`` stands for adding the -specified permission. So, essentially, we are asking ``chmod`` command to -add the execute permission for the user and group. The permission of others -will remain unchanged. +1. How to copy all the contents of one folder into another? -So, if we wished to add the execute permission to all the users, instead of -adding it to just the user and group, we would have instead said +2. How will you rename the file wonderland.txt to alice.txt using the + commands learnt so far? -.. L26 -:: +.. L23 - chmod a+x foo.sh +{{{ Solution of self assessment questions on slide }}} -.. R27 +.. R23 -or +And the answers, -.. L27 +1. We use the ``cp`` command along with a star sign. The star denotes that + it will copy all the files of folder 1 to folder 2. :: - chmod ugo+x foo.sh - -.. R28 - -Pause the video here, try out the following exercise and resume the video. - -.. L28 - -.. L29 - -{{{ Show slide with exercise 1 }}} - -.. R29 - -Change the permissions of a directory along with all of its -sub-directories and files. - -.. L30 - -{{{ Show slide with solution 1 }}} - -.. R30 - -To change the permissions of a directory along with all of its -sub-directories and files, recursively, we use the ``-R`` option -with the chmod command as shown - - chmod go-r -R <directory name>/ - -.. R31 - -It is important to note that the permissions of a file can only be changed -by a user who is the owner of a file or the superuser. - -What if we wish to change the ownership of a file? The ``chown`` command is -used to change the owner and group. -By default, the owner of a file (or directory) is the user that -created it. The group is a set of users that share the same access -permissions i.e., read, write and execute. -For instance, to change the user and the group of the file -``wonderland.txt`` to ``alice`` and ``users``, respectively, we say. + cp folder1/* folder2 -.. L31 +2. To rename a file, we use the ``mv`` command as, :: - chown fossee:users wonderland.txt - -.. R32 - -We get an error saying, the operation is not permitted. -We have attempted to change the ownership of a file that we own, to a -different user. Logically, this shouldn't be possible, because, this can -lead to problems, in a multi-user system. -Only the superuser is allowed to change the ownership of a file from one -user to another. The superuser or the ``root`` user is the only user -empowered to a certain set of tasks and hence is called the superuser. The -command above would have worked, if you did login as the superuser and -then changed the ownership of the file. - -.. L32 - -.. L33 + mv wonderland.txt alice.txt -{{{ Show summary slide }}} +.. L24 -.. R33 +{{{ Show the SDES & FOSSEE slide }}} -This brings us to the end of the tutorial.In this tutorial, we have learnt to, +.. R24 - 1. Copy and move files from one location to another, using the ``cp`` - and ``mv`` commands respectively. - #. Remove files using ``rm`` command. - #. Understand the Linux file hierarchy. - #. Change permissions and ownership of files, using the ``chmod`` - and ``chown`` commands respectively. +Software Development techniques for Engineers and Scientists - SDES, is an +initiative by FOSSEE. For more information, please visit the given link. -.. L34 +Free and Open-source Software for Science and Engineering Education - FOSSEE, is +based at IIT Bombay which is funded by MHRD as part of National Mission on +Education through ICT. -{{{ Show self assessment questions slide }}} +.. L25 -.. R34 +{{{ Show the ``About the Spoken Tutorial Project'' slide }}} -Here are some self assessment questions for you to solve +.. R25 -1. How to copy all the contents of one folder into another? +Watch the video available at the following link. It summarises the Spoken +Tutorial project.If you do not have good bandwidth, you can download and +watch it. -2. How will you rename the file wonderland.txt to alice.txt using the - commands learnt so far? +.. L26 -.. L35 +{{{ Show the `` Spoken Tutorial Workshops'' slide }}} -{{{ Solution of self assessment questions on slide }}} +.. R26 -.. R35 +The Spoken Tutorial Project Team conducts workshops using spoken tutorials, +gives certificates to those who pass an online test. -And the answers, +For more details, contact contact@spoken-tutorial.org -1. We use the ``cp`` command along with a star sign. The star denotes that - it will copy all the files of folder 1 to folder 2. -:: +.. L27 - cp folder1/* folder2 +{{{ Show the ``Acknowledgements'' slide }}} -2. To rename a file, we use the ``mv`` command as, -:: +.. R27 - mv wonderland.txt alice.txt +Spoken Tutorial Project is a part of the "Talk to a Teacher" project. +It is supported by the National Mission on Education through ICT, MHRD, +Government of India. More information on this mission is available at the +given link. -.. L36 +.. L28 {{{ Show the Thankyou slide }}} -.. R36 +.. R28 Hope you have enjoyed this tutorial and found it useful. Thank you! |