C-and-C++/C4/File-Handling-In-C/English-timed

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Time Narration
00:01 Welcome to the spoken-tutorial on files in C .
00:05 In this tutorial we will learn:
00:08 How to open a file.
00:10 How to read data from a file.
00:12 How to write data into a file.
00:15 Few examples.
00:17 To record this tutorial, I am using
00:20 Ubuntu Operating System version 11.10,
00:24 gcc Compiler version 4.6.1.
00:28 Let us start with the introduction to files.
00:31 File is a collection of data.
00:34 It can be a database, a program, a letter or anything.
00:39 We can create a file and access it using C.
00:44 Now let us see an example on file handling in C.
00:48 I have a written program.
00:50 Let's take a look Note that our file name is file.c
00:55 In this program we will create a file and write data into it.
01:01 Let me explain the code now.
01:03 This is our header file.
01:05 This is our main() function.
01:07 To define a file variable we use the type FILE.
01:12 The FILE variable is defined under the header stdio.h.
01:19 *fp is a pointer to the FILE variable.
01:22 It will store all the information about the file ,
01:26 like its name, status and current information.
01:31 Let us go back to our slides.
01:33 Now we will see the syntax to open a file.
01:37 Here, the fopen() function opens a stream.
01:42 Then it links the file with the stream.
01:44 file name is the name of the file that we want to open or create.
01:49 We can give the path along with the file name.
01:53 And We can also give the extension.
01:56 Here we can give the mode of the file.
01:59 Let us see the types of modes :
02:02 "w" - creates file for read and write.
02:06 "r" – opens file for reading.
02:09 "a" – writing at the end of the file.
02:12 Now come back to our program.
02:15 Here, we create a Sample.txt file in write mode.
02:20 We can see that the path is given.
02:23 Our file will be created on the desktop.
02:27 Then we will write the statements into the file.
02:30 "Welcome to the spoken-tutorial" and
02:32 "This is a test example".
02:34 fprintf() writes output to the given output stream.
02:39 fclose() closes the file associated with the stream.
02:43 And this is our return statement.
02:46 Now click on Save.
02:48 Let us execute the program.
02:50 Open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard.
02:59 To compile, type gcc space file dot c space hyphen o space file
03:06 Press Enter To execute, type dot slash file (./file).
03:11 Press Enter.
03:13 We see the file is executed.
03:15 Now we will check it out.
03:17 Let us open the Home folder.
03:20 Click on the Home folder option.
03:22 Now click on the Desktop option.
03:25 Here is our sample.txt file.
03:29 This shows that our file is successfully created.
03:32 Now let us open.
03:34 Double click on the file.
03:36 We can see the messages here.
03:39 Welcome to the Spoken Tutorial.
03:41 This is a test example.
03:44 This is how we create a file and write data into it.
03:48 Now we will see how to read data from a file.
03:52 I have already made the program.
03:54 I will open it.
03:56 In this program, we will read data from our sample.txt file and print the data on the console.
04:03 Let me explain the code now.
04:05 This is our header file.
04:08 This is our main() function.
04:10 Here, a file variable and a pointer to the file variable is defined.
04:15 Then we have declared a character variable c.
04:19 Here, we open the file Sample.txt in read mode.
04:24 The output is stored in fp.
04:27 Then we check the condition-
04:29 "If fp is equal to NULL ".
04:32 If the condition is true then we print the message:
04:36 "File doesn't exist."
04:38 Else, it will check for another condition-
04:41 While c is not equal to EOF.
04:46 Here, EOF is the end of file.
04:49 It denotes the end of input.
04:52 It is a condition where no more data can be read from a data source.
04:57 If the condition is true then it will display the characters from Sample.txt file, on the console.
05:06 Here, getc returns a character from a specified file or stream.
05:12 Now, it will return a character from our Sample.txt file.
05:17 putchar is used to display a character on the console.
05:22 Then it will store the characters in variable c.
05:25 Here we close the file.
05:28 And this is our return statement.
05:30 Now click on Save.
05:32 Let us execute the program.
05:35 Come back to the terminal.
05:37 To compile, type gcc space readfile dot c space hyphen o space read
05:45 Now press Enter .
05:47 To execute, type ./read (dot slash read).
05:52 The output is displayed as:
05:54 Welcome to the Spoken-Tutorial.
05:56 This is a test example.
05:59 This brings us to the end of this tutorial.
06:01 Come back to our slides.
06:03 Let us summarize .In this tutorial we learnt:
06:06 File handling,
06:08 To write data into a file.
06:10 eg. fp = fopen(“Sample.txt”, “w”);
06:17 To read data from a file. eg. fp = fopen(“Sample.txt”, “r”);
06:25 As an assignment- Write a program to create a file TEST.
06:30 Write your name and address in the file TEST.
06:33 Then display it on the console using C Program.
06:37 Watch the video available at the link shown below.
06:40 It summarizes the Spoken Tutorial project.
06:43 If you do not have good bandwidth, you can download and watch it.
06:47 The Spoken Tutorial Project Team:
06:50 Conducts workshops using spoken tutorials.
06:53 Gives certificates to those who pass an online test.
06:57 For more details, please write to, contact@spoken-tutorial.org.
07:03 Spoken Tutorial Project is a part of Talk to a Teacher project.
07:07 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
07:14 More information on this Mission is available at the link shown below.
07:18 This is Ashwini Patil from IIT Bombay, signing off.
07:22 Thank You for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14