Difference between revisions of "Scilab/C4/File-handling/English-timed"

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|Welcome to this spoken tutorial on File Handling using Scilab.  

|Welcome to this spoken tutorial on File Handling using Scilab.  

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| In this tutorial, we will learn  

| In this tutorial, we will learn  

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|'''File Handling''' with the following functions;  

|'''File Handling''' with the following functions;  

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|'''Write Function'''  

|'''Write Function'''  

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|'''Read Function'''  

|'''Read Function'''  

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|'''mopen'''  

|'''mopen'''  

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|'''mclose'''  

|'''mclose'''  

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|For Demonstration i am using '''Ubuntu Linux12.04''' operating system with '''Scilab''' version 5.3.3 installed  

|For Demonstration i am using '''Ubuntu Linux12.04''' operating system with '''Scilab''' version 5.3.3 installed  

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| You should have Basic knowledge of '''Scilab'''.  

| You should have Basic knowledge of '''Scilab'''.  

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| If not, for relevant spoken tutorials please visit '''spoken hyphen tutorial dot org'''  

| If not, for relevant spoken tutorials please visit '''spoken hyphen tutorial dot org'''  

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|| Now we will see some functions in '''scilab''' which are useful for '''File Handling'''.

|| Now we will see some functions in '''scilab''' which are useful for '''File Handling'''.

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|'''File Handling''' involves-  

|'''File Handling''' involves-  

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| writing to a file using '''write function''',  

| writing to a file using '''write function''',  

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| reading from a file using '''read function''',  

| reading from a file using '''read function''',  

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| opening an existing file using '''mopen function''' and  

| opening an existing file using '''mopen function''' and  

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| closing an already opened file using '''mclose function'''.  

| closing an already opened file using '''mclose function'''.  

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| Let us start with writing data to a file.  

| Let us start with writing data to a file.  

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|For this purpose the '''write()''' command is used.  

|For this purpose the '''write()''' command is used.  

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|Switch to the scilab console window.  

|Switch to the scilab console window.  

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|To begin with let us create a matrix of random numbers.  

|To begin with let us create a matrix of random numbers.  

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|| Type; ''' random underscore matrix is equal to rand into bracket 20 comma 1 close the bracket semicolon and press enter'''

|| Type; ''' random underscore matrix is equal to rand into bracket 20 comma 1 close the bracket semicolon and press enter'''

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| Now check the present working directory.  

| Now check the present working directory.  

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|| Type  '''pwd '''

|| Type  '''pwd '''

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| In my case the present working directory is '''slash home slash fossee '''

| In my case the present working directory is '''slash home slash fossee '''

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| Make sure that you are in a directory where you have read & write permission , before you execute these commands.  

| Make sure that you are in a directory where you have read & write permission , before you execute these commands.  

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|| Now we will write the content of variable '''random underscore matrix''' into a text file using the write command.  

|| Now we will write the content of variable '''random underscore matrix''' into a text file using the write command.  

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| Type;--> '''write into bracket into quotes random dash numbers dot txt close  the  quotes comma random underscore matrix close the bracket and press enter'''

| Type;--> '''write into bracket into quotes random dash numbers dot txt close  the  quotes comma random underscore matrix close the bracket and press enter'''

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|Let us see whether this file has been created.  

|Let us see whether this file has been created.  

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||I will minimize the '''scilab''' console window.  

||I will minimize the '''scilab''' console window.  

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|And open the file which will be created and saved in the fossee directory of my computer.  

|And open the file which will be created and saved in the fossee directory of my computer.  

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|| You can see the data from variable '''random underscore matrix is written in a text file random dash numbers dot txt'''

|| You can see the data from variable '''random underscore matrix is written in a text file random dash numbers dot txt'''

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|| I will close this file.

|| I will close this file.

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| Coming back to the scilab console.  

| Coming back to the scilab console.  

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| Now we will see how to read the data from a file.

| Now we will see how to read the data from a file.

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|| For this we will use the command read as follows,  

|| For this we will use the command read as follows,  

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| Type '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt close the quotes comma 20 comma 1 close the bracket and press enter'''.

| Type '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt close the quotes comma 20 comma 1 close the bracket and press enter'''.

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| The read command reads all the data from the file mentioned in the argument,  

| The read command reads all the data from the file mentioned in the argument,  

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| In this case '''random dash numbers dot txt''',

| In this case '''random dash numbers dot txt''',

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| And stores in the variable '''new underscore vector'''

| And stores in the variable '''new underscore vector'''

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|  Press Enter to continue the display  

|  Press Enter to continue the display  

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| If we modify the above command as  

| If we modify the above command as  

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| '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1 '''

| '''new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1 '''

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| The read command reads only 19 data values from the file mentioned in this argument.  

| The read command reads only 19 data values from the file mentioned in this argument.  

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|In this case '''random dash numbers dot txt'''

|In this case '''random dash numbers dot txt'''

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|| And stores in the variable '''new underscore vector'''.  

|| And stores in the variable '''new underscore vector'''.  

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| |Issue this command on the '''scilab''' console and verify the output.  

| |Issue this command on the '''scilab''' console and verify the output.  

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||Now let us see about the mopen function:  

||Now let us see about the mopen function:  

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||'''fd = mopen into bracket file-name comma mode'''

||'''fd = mopen into bracket file-name comma mode'''

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|mopen command is used to open an existing file in a way compatible to C fopen procedure.  

|mopen command is used to open an existing file in a way compatible to C fopen procedure.  

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| mode is a character string that controls whether the file is opened for  

| mode is a character string that controls whether the file is opened for  

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| r = Opens the file for reading.  

| r = Opens the file for reading.  

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| rb = Opens a binary file for reading.  

| rb = Opens a binary file for reading.  

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| rt = Opens a text file for reading.  

| rt = Opens a text file for reading.  

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||w = Creates a new file for writing, or opens and truncates a file to zero length.  

||w = Creates a new file for writing, or opens and truncates a file to zero length.  

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| wb = Creates a new binary file for writing, or opens and truncates a file to zero length.  

| wb = Creates a new binary file for writing, or opens and truncates a file to zero length.  

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| |wt = Creates a text binary file for writing, or opens and truncates a file to zero length.  

| |wt = Creates a text binary file for writing, or opens and truncates a file to zero length.  

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|a or ab = Appends (opens a file for writing at the end of the file, or creates a file for writing).  

|a or ab = Appends (opens a file for writing at the end of the file, or creates a file for writing).  

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| r+ or r+b = Opens a file for update (reading and writing)  

| r+ or r+b = Opens a file for update (reading and writing)  

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| For eg '''fd underscore r is equal to mopen('random-numbers,'rt')'''

| For eg '''fd underscore r is equal to mopen('random-numbers,'rt')'''

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||the above command opens the 'random-numbers' as a text and read-only mode.  

||the above command opens the 'random-numbers' as a text and read-only mode.  

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||'''mclose into bracket fd''':  

||'''mclose into bracket fd''':  

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|| closes the opened file by using mopen.  

|| closes the opened file by using mopen.  

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|where fd is the file descriptor of the opened file  

|where fd is the file descriptor of the opened file  

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| If fd is omitted mclose closes the last opened file.  

| If fd is omitted mclose closes the last opened file.  

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|That's all we have in this tutorial.  

|That's all we have in this tutorial.  

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| We have learnt -  

| We have learnt -  

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| File Handling with the following functions:  

| File Handling with the following functions:  

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||''' Write Function'''  

||''' Write Function'''  

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| '''Read Function'''  

| '''Read Function'''  

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| '''mopen'''  

| '''mopen'''  

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| '''mclose'''  

| '''mclose'''  

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| Watch the video available at the following link  

| Watch the video available at the following link  

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|-

| It summarises the Spoken Tutorial project  

| It summarises the Spoken Tutorial project  

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|-

||If you do not have good bandwidth, you can download and watch it  

||If you do not have good bandwidth, you can download and watch it  

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|-

||The spoken tutorial Team

||The spoken tutorial Team

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|-

||Conducts workshops using spoken tutorials  

||Conducts workshops using spoken tutorials  

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|-

||Gives certificates to those who pass an online test  

||Gives certificates to those who pass an online test  

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|-

||For more details, please write to conatct@spoken-tutorial.org  

||For more details, please write to conatct@spoken-tutorial.org  

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|Spoken Tutorial Project is a part of the Talk to a Teacher project  

|Spoken Tutorial Project is a part of the Talk to a Teacher project  

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|-

| It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.  

| It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.  

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|-

|More information on this mission is available at  http://spoken-tutorial.org/NMEICT-Intro

|More information on this mission is available at  http://spoken-tutorial.org/NMEICT-Intro

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|-

|This is Anuradha Amrutkar from IIT Bombay signing off.

|This is Anuradha Amrutkar from IIT Bombay signing off.

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|-

| Thank you for joining.

| Thank you for joining.