This document discusses file handling in C programming. It covers objectives like understanding different file types, modes for opening files, functions for reading and writing files. Specific functions covered are fopen(), fprintf(), fscanf(), fgetc(), fputc(), fclose(), fseek(). It provides examples to open and read text files, write and read from binary files using functions like fwrite() and fread(). The last example shows storing and retrieving student record from a file using structure and file handling.

1. PAPER: INTRODUCTION PROGRAMMING LANGUAGE USING C
PAPER ID: 20105
PAPER CODE: BCA 105
DR. VARUN TIWARI
(ASSOCIATE PROFESSOR)
(DEPARTMENT OF COMPUTER SCIENCE)
BOSCO TECHNICAL TRAINING SOCIETY,
DON BOSCO TECHNICAL SCHOOL, OKHLA ROAD , NEW DELHI

2. C FILE HANDLING

3. OBJECTIVES
IN THIS CHAPTER YOU WILL LEARN:
1. TO LEARN ABOUT FILE HANDLING.
2. TO UNDERSTAND TYPES OF FILES IN C.
3. TO UNDERSTAND ABOUT MODES OF FILES IN C.
4. TO LEARN ABOUT READ AND WRITE DATA IN FILE.
5. TO LEARN ABOUT HOW TO COPY CONTENT FROM ONE FILE TO ANOTHER FILE IN C.

4. FILE : OFTEN DATA IS SO LARGE THAT ALL OF IT CANNOT STORED IN MEMORY AND ONLY A LIMITED
AMOUNT OF IT, CAN BE DISPLAYED ON THE SCREEN. ALSO MEMORY IS VOLATILE AND ITS CONTENTS
WOULD BE LOST ONCE THE PROGRAM TERMINATED. SO THAT SUPPOSE IF YOU WANT TO STORE DATA
THAN YOU USE A FILE HANDLING TECHNIQUE TO STORE DATA IN FILE. THERE ARE TWO TYPES OF FILES
(TEXT FILES (.TXT,.C) AND BINARY FILES (.BIN, .DAT FILE)).
THERE ARE DIFFERENT OPERATIONS THAT CAN BE CARRIED OUT ON A FILE. THESE ARE-:
1. CREATE A NEW FILE
2. OPENING AN EXISTING FILE
3. READING DATA FROM FILE
4. WRITING DATA IN TO FILE
5. MOVING TO A SPECIFIC LOCATION IN A FILE(SEEKING)
6. CLOSING A FILE.

5. FUNCTIONS OF FILE:
Function Description
fopen() opens new or existing file
fprintf() write data into the file
fscanf() reads data from the file
fputc() writes a character into the file
fgetc() reads a character from file
fclose() closes the file
fseek() sets the file pointer to given position

6. TEXT FILE AND BINARY FILE MODE FOR OPENING A FILE:
Mode Description
r opens a text file in read mode
w opens a text file in write mode
a opens a text file in append mode
r+ opens a text file in read and write mode
w+ opens a text file in read and write mode
a+ opens a text file in read and write mode
rb opens a binary file in read mode
wb opens a binary file in write mode
ab opens a binary file in append mode
rb+ opens a binary file in read and write mode
wb+ opens a binary file in read and write mode
ab+ opens a binary file in read and write mode

7. FILE OPEN FOPEN(), FGETC() :
SYNTAX : FILE *FOPEN( CONST CHAR * FILENAME, CONST CHAR * MODE );
EX-:
#include<stdio.h>
void main( ) {
file *a ; // file pointer create (create a file)
char c ;
a = fopen("struct1.c","r") ; // opening a file via fopen()
while(1) //until the data available in file
{ c = fgetc ( a ) ; // fgetc read character in afile
if ( c == eof ) // check character until end of file
break ;
printf("%c",c) ; // print character }
fclose (a) ; }

8. FILE OPEN FSCANF() AND FPRINTF() :
SYNTAX : INT FPRINTF(FILE *STREAM, CONST CHAR *FORMAT [, ARGUMENT, ...])
INT FSCANF(FILE *STREAM, CONST CHAR *FORMAT [, ARGUMENT, ...])
EX-:
#include<stdio.h>
void main(){
FILE *a;
a = fopen("file.txt", "w");//opening file
fprintf(a, "Hello how r u.n");//writing data into file
fclose(a);//closing file
}

9. INT FSCANF(FILE *STREAM, CONST CHAR *FORMAT [, ARGUMENT, ...])
EX-:
#include<stdio.h>
void main(){
FILE *a;
char b[100];//creating char array to store data of file
a = fopen("file.txt", "r");
while(fscanf(a, "%s", b)!=eof()){
printf("%s ", b);
} fclose(fp); }

10. STORE STUDENT INFO BY USING FILE HANDLING
#include<stdio.h>
#include<conio.h>
struct stud { int sid;
char sname[20]; int sage;
}; void main() {
struct stud s; FILE *a,*b;
a = fopen("stud.txt", "w"); b = fopen("stud.txt", "r");
printf("n Enter student id , student name and sage");
scanf("%d %s %d", &s.sid,s.sname,&s.sage);
fprintf(a,"%d %s %d", s.sid,s.sname, s.sage);
fclose(a); printf("n The Value of Sid , Sname and sage is-:");
do {
fscanf(b,"%d %s %d", s.sid,s.sname, s.sage); printf("%d %s %d",s.sid, s.sname, s.sage); }
while(!eof(b)); getch(); }

11. FGETC() AND FPUTC()
SYNTAX: CHAR* FGETS(CHAR *S, INT N, FILE *STREAM) , INT FPUTS(CONST CHAR *S, FILE *STREAM)
void main(){ FILE *a;
clrscr(); a=fopen(“abc.txt","w");
fputs("hello how r u",a);
fclose(a); getch(); }
void main(){ FILE *a;
char b[100]; clrscr();
a=fopen(“abc.txt","r");
printf("%s",fgets(b,100,a));
fclose(a); getch();
}

12. FSEEK() : INT FSEEK(FILE *STREAM, LONG INT OFFSET, INT WHERE)
THERE ARE 3 CONSTANTS USED IN THE FSEEK() FUNCTION FOR WHERE: SEEK_SET, SEEK_CUR AND
SEEK_END.
void main(){
FILE *a;
a = fopen(“abc.txt","w+");
fputs(“this is my first program", a);
fseek( a, 3, SEEK_SET );
fputs(“c program", a);
fclose(a); }

13. BINARY FILE FWRITE() :
#include<stdio.h>
struct book{ int bid;
char bname[20]; int bisbn; };
void main() {
struct book b; FILE *fp;
fp = fopen("book.dat","wb");
if(fp == NULL){ puts("Cannot open file"); }
printf("n Enter book id, book name, book isbn");
scanf("%d%s%d",&b.bid,b.bname,&b.bisbn);
fwrite(&b,sizeof(b),1,fp);
fclose(fp); }

14. BINARY FILE FREAD() :
#include<stdio.h>
struct book{ int bid;
char bname[20]; int bisbn; };
void main() {
struct book b; file *fp;
fp=fopen("book.dat","rb");
while(fread(&b,sizeof(b),1,fp)==1)
{
printf("%d %s %dn",b.bid,b.bname,b.bisbn);
}
fclose(fp); getch(); }

15. THANK YOU