https://process.spoken-tutorial.org/index.php?action=history&feed=atom&title=Linux_Spoken_Tutorial%2FBasic_Level_Tutorial_Set%2FLinux-part2Linux Spoken Tutorial/Basic Level Tutorial Set/Linux-part2 - Revision history2026-05-21T20:20:02ZRevision history for this page on the wikiMediaWiki 1.23.17https://process.spoken-tutorial.org/index.php?title=Linux_Spoken_Tutorial/Basic_Level_Tutorial_Set/Linux-part2&diff=215&oldid=prevSanmugam: Created page with 'Spoken tutorial on basic linux commands part – 2 {| style="border-spacing:0;" | style="border-top:0.035cm solid #000000;border-bottom:0.035cm solid #000000;border-left:0.035…'2013-01-09T11:00:50Z<p>Created page with 'Spoken tutorial on basic linux commands part – 2 {| style="border-spacing:0;" | style="border-top:0.035cm solid #000000;border-bottom:0.035cm solid #000000;border-left:0.035…'</p>
<p><b>New page</b></p><div>Spoken tutorial on basic linux commands part – 2<br />
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{| style="border-spacing:0;"<br />
| style="border-top:0.035cm solid #000000;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| <center>'''Visual Cue'''</center><br />
| style="border:0.035cm solid #000000;padding:0.097cm;"| <center>'''Narration'''</center><br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Show first slide from the presentation<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Dear friends,<br />
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Welcome to the second part of spoken tutorial on basic linux commands In this tutorial we will focus on directory operaions and file permissions.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Show second slide from the presentation<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| First command that we will cover is '''mkdir. '''This command creates a new directory in linux file system.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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mkdir testdir<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To create a new directory we will type '''mkdir tesdir'''<nowiki>. This will create a new directory called testdir. <pause> Let us now list all sub directories under the current directory and see if new directory has been created.</nowiki><br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Type ls and highlight the newly created directory<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| As you can see we success fully create a new directory called testdir.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Mkdir can create multiple directories under a given path. When used with -p switch, mkdir will create all the required directories in a given path.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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mkdir -p /tmp/hello/world<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| We will now create a new directory called hello in the /tmp directory and another subdirectory called world under the newly created hello directory.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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ls /tmp && ls /tmp/hello<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| As you can this command created a directory called hello and a subdirectory called world under hello.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Show slide number 3<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Let us now create a directory structure as shown in the figure.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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mkdir -p tmpdir/{apple,orange,mango/variety/{alphanso,extrema,haden},peach}<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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ls tmpdir && tmpdir/mango/variety<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>As you can see, we create the required directory with a single command. <pause></nowiki><br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide 4<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Now lets move to next command. <pause> chown is a command used to change the ownership of a file or directory. </nowiki><br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To change the ownership of a file or directory, type chown followed by options and filename.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type<br />
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chown root tmpdir<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>This command will change the ownership of the tmpdir to root user.<pause></nowiki><br />
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You can specify the oner user and owner group for a file with chown.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type<br />
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chown nobody.nogroup tmpdir<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| This command will change the ownership of '''tmpdir '''to nobody user and nogroup group.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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chmod -R nobody.nogroup tmpdir<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| You can change the ownership of all files and subdirectories in a given directory at once, '''recursively.''' The -R will make chown change permissions of all files and directories recursively.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 5<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Before moving to our next command, lets look at a unix file permissions. <pause> </nowiki><nowiki>In unix world, every file and directory has permissions associated with it. These permissions control who can read, write or execute a file or directory.<pause> An user will require execute permission on a directory, if he wants to change directory to a given directory.<pause></nowiki><br />
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Let us now look at few files and the permissions associated with the files.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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ls -l<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>As you can see with every file you have some permissions. <highlight the permission bits in the console>. <pause> First thre e letters will tell you the permissions that owner of a file has <highlight first three rwx bits>. <pause> Next three letters will tel you what permissions the owner group of the file has <highlight next three bits of the permissions> <pause>. Last three letters will tell you what are the permissions for rest of the world.<pause></nowiki><br />
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A '''r''' in first place means you have '''read'''<nowiki> permissions on the file.<pause> A </nowiki>'''w''' in second position means you have '''write'''<nowiki> permission on the file.<pause> A </nowiki>'''x''' in third position means you have '''execute''' permission on the file.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| <br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 6<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Let us now look at chmod command in unix world that lets you change the permissions of a file<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type <br />
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ls -l abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| You can see that file has only read permissions. Let us add write permissions to the owner of the file.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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chmod u+w abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| In this command '''u''' represents user permissions and '''plus sign''' represents adding permissions.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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chmod a-w abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To remove a specific permission from a file you have to use '''minus sign'''.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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chmod g+w abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To add permissions for a group we will use '''g''' instead of '''u'''.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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chmod a+w abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To give write permission to all users, we will use '''a plus w'''. <br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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chmod -r a+w tmpdir<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To grant write permissions to all files in a directory you can use -R option. This option will recursively apply the specified permissions.<br />
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|-<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 7 <br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Our next command is '''chgrp''' which allows you to change the group of a file.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type<br />
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chgrp nogroup abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>To change the group of a file we will type the following command <type the command in the console></nowiki><br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type<br />
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ls -l<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| As we can see the group of the file abc.txt is now changed to nogroup.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 8<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Our next command is '''rm'''. This command lets us remove files and directories from the file system.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type <br />
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rm abc.txt<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>To remove a file simply type following command <type the command in the console>.</nowiki><br />
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rm -r temp<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Rm will not remove a directory by default. You have to specify the '''-r'''<nowiki> switch to remove the directory.<pause> You can also force the removal of a file or directory by using a </nowiki>'''-f '''switch.<br />
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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide 9<br />
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| This brings us to the end of the second part of spoken tutorial on basic linux commands. Thanks for watching this tutorial.<br />
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|}</div>Sanmugam