Scilab/C4/File-handling/English-timed
From Script | Spoken-Tutorial
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Time | Narration |
00:01 | Welcome to this spoken tutorial on File Handling using Scilab. |
00:06. | In this tutorial, we will learn |
00:08 | File Handling with the following functions; |
00:11 | Write Function |
00:12 | Read Function |
00:14 | mopen |
00:15 | mclose |
00:16 | For Demonstration i am using Ubuntu Linux12.04 operating system with Scilab version 5.3.3 installed |
00:26 | You should have Basic knowledge of Scilab. |
00:29 | If not, for relevant spoken tutorials please visit spoken hyphen tutorial dot org |
00:36 | Now we will see some functions in scilab which are useful for File Handling. |
00:41 | File Handling involves-
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00:44 | writing to a file using write function, |
00:47 | reading from a file using read function, |
00:51 | opening an existing file using mopen function and |
00:55 | closing an already opened file using mclose function. |
01:00 | Let us start with writing data to a file. |
01:03 | For this purpose the write() command is used.
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01:07 | Switch to the scilab console window. |
01:10 | To begin with let us create a matrix of random numbers. |
01:15 | Type; random underscore matrix is equal to rand into bracket 20 comma 1 close the bracket semicolon and press enter
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01:29 | Now check the present working directory. |
01:32 | Type pwd
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01:34 | In my case the present working directory is slash home slash fossee |
01:39 | Make sure that you are in a directory where you have read & write permission , before you execute these commands.
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01:47 | Now we will write the content of variable random underscore matrix into a text file using the write command.
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01:55 | 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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02:18 | Let us see whether this file has been created. |
02:21 | I will minimize the scilab console window.
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02:23 | And open the file which will be created and saved in the fossee directory of my computer. |
02:33 | You can see the data from variable random underscore matrix is written in a text file random dash numbers dot txt |
02:42 | I will close this file. |
02:45 | Coming back to the scilab console. |
02:47 | Now we will see how to read the data from a file. |
02:50 | For this we will use the command read as follows, |
02:55 | 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. |
03:18 | The read command reads all the data from the file mentioned in the argument, |
03:23 | In this case random dash numbers dot txt, |
03:27 | And stores in the variable new underscore vector |
03:31 | Press Enter to continue the display |
03:35 | If we modify the above command as
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03:39 | new underscore vector is equal to read into bracket into quote random dash numbers dot txt comma 19 comma 1 |
03:49 | The read command reads only 19 data values from the file mentioned in this argument. |
03:56 | In this case random dash numbers dot txt
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03:59 | And stores in the variable new underscore vector. |
04:03 | Issue this command on the scilab console and verify the output.
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04:08 | Now let us see about the mopen function:
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04:12 | fd = mopen into bracket file-name comma mode |
04:17 | mopen command is used to open an existing file in a way compatible to C fopen procedure.
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04:25 | mode is a character string that controls whether the file is opened for
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04:30 | r = Opens the file for reading.
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04:34 | rb = Opens a binary file for reading.
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04:39 | rt = Opens a text file for reading.
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04:43 | w = Creates a new file for writing, or opens and truncates a file to zero length.
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04:50 | wb = Creates a new binary file for writing, or opens and truncates a file to zero length.
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04:58 | wt = Creates a text binary file for writing, or opens and truncates a file to zero length.
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05:06 | 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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05:14 | r+ or r+b = Opens a file for update (reading and writing)
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05:20 | For eg fd underscore r is equal to mopen('random-numbers,'rt')
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05:30 | the above command opens the 'random-numbers' as a text and read-only mode.
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05:37 | mclose into bracket fd: |
05:40 | closes the opened file by using mopen. |
05:43 | where fd is the file descriptor of the opened file |
05:48 | If fd is omitted mclose closes the last opened file. |
05:53 | That's all we have in this tutorial.
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05:55 | We have learnt -
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05:56 | File Handling with the following functions:
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05:59 | Write Function
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06:00 | Read Function
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06:02 | mopen
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06:03 | mclose
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06:05 | Watch the video available at the following link |
06:08 | It summarises the Spoken Tutorial project
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06:11 | If you do not have good bandwidth, you can download and watch it |
06:14 | The spoken tutorial Team |
06:17 | Conducts workshops using spoken tutorials
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06:20 | Gives certificates to those who pass an online test
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06:23 | For more details, please write to conatct@spoken-tutorial.org
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06:30 | Spoken Tutorial Project is a part of the Talk to a Teacher project
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06:34 | It is supported by the National Mission on Eduction through ICT, MHRD, Government of India. |
06:41 | More information on this mission is available at http://spoken-tutorial.org/NMEICT-Intro |
06:50 | This is Anuradha Amrutkar from IIT Bombay signing off. |
06:54 | Thank you for joining. |