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

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

| 00:06.

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

|'''Write Function'''  

 

|'''Read Function'''  

|'''mopen'''  

 

|'''mclose'''  

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

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

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

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

|'''File Handling''' involves-  

 

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

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

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

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

|Switch to the scilab console window.  

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

 

|| Type  '''pwd '''

 

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

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

 

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

 

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

 

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

 

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

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

| Coming back to the scilab console.  

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

| 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'''.

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

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

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

|  Press Enter to continue the display  

| If we modify the above command as  

 

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

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

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

 

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

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

 

||Now let us see about the mopen function:  

 

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

 

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

 

| r = Opens the file for reading.  

 

 

| rb = Opens a binary file for reading.  

 

| rt = Opens a text file for reading.  

 

 

||w = Creates a new 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.  

 

 

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

 

 

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

 

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

 

 

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

 

 

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

 

 

||'''mclose into bracket fd''':  

|| closes the opened file by using mopen.

|where fd is the file descriptor of the opened file  

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

| We have learnt -  

 

 

 

 

| File Handling with the following functions:  

 

||''' Write Function'''  

 

 

 

 

 

| '''Read Function'''  

 

| '''mopen'''  

 

 

| 06:03

 

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|This is Anuradha Amrutkar from IIT Bombay signing off.