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

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 339: Line 339:
 
| 05.37
 
| 05.37
  
||mclose into bracket fd:  
+
||'''mclose into bracket fd''':  
  
 
|-
 
|-

Revision as of 15:04, 7 March 2014

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-


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.


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


01.29 Now check the present working directory.
01.32 Type pwd


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.


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


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


02.18 Let us see whether this file has been created.
02.21 I will minimize the scilab console window.


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


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


03.59 And stores in the variable new underscore vector.
04.03 Issue this command on the scilab console and verify the output.


04.08 Now let us see about the mopen function:


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.


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


04.30 r = Opens the file for reading.


04.34 rb = Opens a binary file for reading.


04.39 rt = Opens a text file for reading.


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


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


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


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


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


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


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


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.


05.55 We have learnt -


05.56 File Handling with the following functions:


05.59 Write Function


06.00 Read Function


06.02 mopen


06.03 mclose


06.05 Watch the video available at the following link
06.08 It summarises the Spoken Tutorial project


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


06.20 Gives certificates to those who pass an online test


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


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


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.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14