Difference between revisions of "BOSS-Linux/C2/Simple-filters/English-timed"

| Hello and welcome to the Spoken Tutorial on Simple Filters with Linux.  

| All these are command line text manipulation tools.  

| If you see a hash (#) symbol on the Terminal you need to become root to execute those commands   

|'''sudo su''' or '''su root''', if you see a dollar symbol on the Terminal you can be an ordinary user to execute those commands.  

| I assume that you did a default installation and did not modify any path where the files are getting saved.  

| I am using Linux for this tutorial.  

|Prerequisites for this module are the ability to use the mouse , keyboard, maximize and minimize buttons on a window.

| We use the '''Head''' command followed by an '''ascii''' file name, to display the first 10 lines of a file by default.  

|I already have these numbers in another file for the sake of time constrain .  

| Hit on '''File''' , '''Save.'''  

|Name the file as '''numbers dot txt''' and hit on '''save'''  

| Now go to '''Applications > Accessories > Terminal.'''  

|Type '''ls''' and hit on '''enter.'''  

| '''Cat n-u-m''' Hit on '''tab''' to autofill the file name. Hit on '''Enter.'''

| '''head numbers dot txt''', '''enter'''

| If we want to see the first 5 lines, use the option ''' hyphen n5''' in between the '''head''' command and the file.  

| Hit on Up arrow,  '''hyphen n5''' and '''Enter.'''

|Let us switch back to the presentation  

| The '''tail''' command works exactly opposite to the '''head''' command, it displays the last 10 lines of a file by default.

| I am hitting on '''ALT''' and '''Tab''' to switch to the terminal.

| '''hyphen n5''', '''Enter'''  

| Switch to slides

| The most useful option of the tail command is to use '''hyphen f''' option to follow the tail of a log file.  

|If a new line is appended to the log file, the '''tail''' command will take that as the last line and display 10 lines by default above it.  

| Go to the terminal

|'''tail hyphen f forward slash var slash log slash auth dot log'''

| Let me resize this terminal

| Let us open another Terminal , '''Application- > Accessories - > Terminal.'''

| Try to '''su''' as yourself, hit on '''enter.'''  

| Give in some wrong password hit on '''enter.'''

| Type '''date''' hit on '''enter''' to verify the system date and time.

|These are the commonly used log files in Linux.  

| A linux system administrator will look into these log files for more information to troubleshoot his machine if there is a problem.

| '''Sort''' command as the name suggest will sort a file for us in both ascending and descending order.  

| '''sort numbers dot txt''' .This would sort our '''numbers dot txt''' file in ascending order.  

| Notice something is strange in there, sort just looks at the first character to sort, so '''10''','''11'''&'''12''' appears before the number 2.  

| To avoid this add the option of '''hyphen n''', hyphen n and  Enter

| Now sort looks at the entire number to sort them.  

| To sort '''number dot txt''' in reverse order add an option of '''hyphen r.'''  

| We have numbers that repeat in this file, to pull out just the unique numbers add another option of '''hyphen u''' .

| Up Arrow  

|'''U,  enter''',  

|Previously two 2's were displayed . Now only one 2 is displayed.

| I already have the data in another file for the sake of time constrain let me copy & Paste the value, '''CTRL+C; CTRL+V.'''  

| Don't mind the special characters on this file I don't want someone to sue me for giving them low marks  

| Let us sort based on the second column of '''marks dot txt file. '''

|'''sort space marks dot txt space hyphen t space open inverted commas space close inverted commas space'''

|here '''hyphen t''' stands for the '''delimiter''' & the space in between the quotes represents it.  

|'''hyphen k2''' for the second column on which sort should be performed.

|'''Cat marks dot txt'''  

|Let us pull out the names from '''marks dot txt'''  

|Let us go to the terminal '''ALT Tab'''  

|here in '''cut''' command '''d''' is the delimiter & the space in between the quotes represents the delimiter.

|'''hyphen f2''' for the second column. Hit on '''enter.'''  

|'''Paste numbers dot txt  marks dot txt''', '''enter'''

|Now the first line of '''marks dot txt''' was appended to the first line of '''numbers dot txt.'''  

| Hit on Up arrow. Hit on the redirect key which is the Greater than symbol '''concatfile dot txt'''. Hit on '''Enter.'''  

| '''Cat concatfile dot txt'''  

| If we want paste to print out the numbers serially delimited with tab we can use the '''hyphen s''' option.  

| Spoken Tutorial project is a part of Talk to a Teacher project,  

|Supported by the National Mission on Education through ICT,MHRD, Government of India.

| For more information you can refer to the following link.

|This is Bala. Thanks a lot for watching this video and dont forget to leave a comment.