C programming disk file reading and writing

1. Presented by Rishi Ram khanal
BIM 2nd semester (TU)
Roll no:108

2. Contents
 Introduction
 Reading file
 Example of reading file
 Writing file
 Example of writing file

3. Introduction
 File is a collection of bytes on a secondary storage
device
 It is a generally disk of some kind
 Bytes may be interpreted like as character, word ,line
and paragraph
 It is simply machine decipherable storage media
where data and programs are stored

4. Reading file
 When r is used, the file is opened for reading
 W is used for indicate a file used for writing
 Indicates that you desire to append additional data to
the already in an existing file
 Using the r indicate that the file is assumed to be a text
file already exist
 If file not exit the fill pointer is set to be null

5. Examples for read
 /*program to display the contents of a fj
 #include<stdio.h>
 Void main ()
 {
 File *fopen (), *fp;
 Int c;
 Fp=fopen(“prog.c”,r);
 While (c!=edf)
 {

6.  Putchar (c);
 C=getch(fp);
 }
 Fclose(fp);
 }

7. Writing “w”
 File is opened for writing
 It will be create if it does not already exist
 It will be reset if does ,resulting in the any data already
there
 Using the w indicates that the file is assumed to be a
text file

8. Example
 #include<stdio.h>
 int main ()
 {
 File *fp;
 File =fopen(“file.txt”,”w”) ;
 /*create a file and a text /*
 Fprintf(fp,“%s”,”this is just an example ”) ;/*writr data
to the file /*

9.  Fclose(fp); /*done*/
 Return 0;
 }