This document discusses various functions used for file handling in C programming. It defines a file and describes basic file operations like opening, closing, reading, and writing to files. It then explains functions like fopen(), fclose(), fprintf(), fscanf(), fgetc(), fputc(), putw(), getw(), fseek(), and ftell() that are used to perform these basic file operations. Examples are provided to demonstrate the usage of each function.

2. What is file?
Operation on a file.
Function using in file handling.
Function with example using in file handling.

3. INTRODUCTIO
N PART

4. What is file?
A file is a space on the disk where a group of related data is
stored.
Operations on a file
DEFINING A FILE
OPENING A FILE
CLOSING A FILE
WRITING DATA TO FILE
READING DATA FROM A FILE

5. Functions that helps to perform basic file operations.
fopen( ) - create a new file or open a existing file
fclose( ) - closes a file
fprintf( ) - writes a set of data to a file
fscanf( ) - reads a set of data from a file
fgetc( ) - reads a character from a file
fputc( ) - writes a character to a file
getw( ) - reads a integer from a file
putw( ) - writes a integer to a file
fseek( ) - set the position to desire point
ftell( ) - gives current position in the file

6. Defining a File
A file is identified by its name. This name is divided into two parts
File Name
 It consists of alphabets and digits.
 Special characters are also supported, but it depends on the operating
system we use.
Extension
 It describes the file type

7. Opening a File
If we want to store data in file in secondary memory then ,
following things are needed:
*Filename: string of characters to make valid name for o/s.
*Data structure : for a file it is defined as a FILE in <stdio.h>
*Purpose: what to do ; like reading ,writing , append

8. Syntax:-
FILE *fp;
fp=fopen(“filename”, “mode”);
modes
r
w
a
Open the file in reading mode
Open the file in writing mode
Open the file for adding data to
it

9. FILE *p1,*p2;
p1=fopen(“data” , “r”);
p2=fopen(“results” , “w”);
Other modes
• The existing file is opened to the
beginning for both reading and writing.
r+
• Same as w except both foe reading
and writing.
w+
• Same as a but both for reading and
writing.
a+

10. Closing a File
A file is closed when all operations on it have been completed.
It ensures that all the data related to file are cleared from the
buffer.
Example:
FILE *p1,*p2;
p1=fopen(“INPUT” , ”w”);
p2=fopen(“OUTPUT” , ”r”);
…………………
…………………
fclose(p1);
fclose(p2);

11. fprintf()
&
fscanf()

12. C library function - fprintf( )
Description:-
The C library function sends formatted output to a stream.
Declaration:-
int fprintf(FILE *stream, const char *format, ...)
Return Value:-
If successful, the total number of characters written is returned
otherwise, a negative number is returned.

13. #include <stdio.h>
#include <conio.h>
void main(){
FILE * fp;
int c;
fp = fopen ("file.txt", “a+");
fprintf(fp, "%s %s %s %d", "We", "are", "in", 2012);
fclose(fp);
fp = fopen("file.txt","r");
while(1){
c = fgetc(fp);
if( feof(fp) ) {
break;}
printf("%c", c);}
fclose(fp);
getch();
}
file.txt
created on
pc
Example using fprintf() function:-

14. C library function - fscanf( )
Description:-
The C library function reads formatted input from a stream.
Declaration:-
int fscanf(FILE *stream, const char *format, ...)

15. #include <stdio.h>
#include <conio.h>
void main()
{
char str1[10], str2[10], str3[10];
int year;
FILE * fp;
fp = fopen ("file.txt", "w+");
fputs(“tWe are in 2012n", fp);
rewind(fp);
fscanf(fp, "%s %s %s %dn", str1, str2, str3, &year);
printf("Read String1 |%s|nRead String2 |%s|nRead String3 |%s|nRead Integer |%d|n", str1,str2,str3,year );
fprintf(fp , “nRead String1 |%s|nRead String2 |%s|nRead String3 |%s|nRead Integer |%d|n", str1,str2,str3,year );
fclose(fp);
getch();
}
Example using fscanf() function:-

16. fgetc()
&
fputc()

17. • fgetc() function is used to read a file line by
line.
• It is used in program as:-
ch=fgetc(fs);
• It returns the character that is read, which
is collected in the variable ‘ch’.
C library function - fgetc( )

18. C library function - fputc( )
• fgetc() is a function which writes
characters to a file.
• It is used in program as:-
fputc(ch,ft);
• With the help of both functions, we can copy contents
of one file to another.

19. Example using fgetc() & fputc() function:-
int main()
{
FILE *fs,*ft;
char ch;
fs=fopen(“PR1.C”,”r”);
if(fs==NULL)
{
printf(“Cannot open ssource file”);
exit(1);
}
ft=fopen(“PR2.C,”w”);
if(ft==NULL)
{
printf(“Cannot open the file”);
fclose(fs);
exit(2);
}
while(1)
{
ch=fgetc(fs);
if(ch==EOF)
break;
else
fputc(ch,ft);
}
fclose(fs);
fclose(ft);
return 0;
}

20. putw()
&
getw()

21. C library function - putw( )
putw() function in “C” programming is use to write
integer data on the file (text file) .
SYNTAX :-
int putw(integer , FILE*);

22. Example using putw() function:-
Void main()
{
FILE *fp;
fp = fopen(“file1.txt”, “w”);
putw(65,fp);
fclose(fp);
}

23. C library function - getw( )
 getw() function in “C” programming language is use
to read the integer data from the file.
SYNTAX :-
int getw(FILE*);

24. Example using getw() function:-
Void main()
{
FILE *fp;
fp = fopen(“file1.txt” , “r” );
printf (“%d” , getw(fp) );
fclose(fp);
}

25. fseek()
&
ftell()

26. Random Access of File
Functions Include:-
1. fseek() = to jump a particular location in a file
2. ftell() = current location in a file

27. Functions used in random access
fseek(): This function is used to move the pointer to a desired position within a
file.
Syntax:
fseek(FILE *stream, long int offset, int whence)
 Stream − This is the pointer to a FILE object that identifies the stream.
 Offset –This specifies the number of positions (bytes)to be moved from the
location specified by position.
 Whence-This is the position from where offset is added. It is specified by
one of the following constants
Constant Description
SEEK_SET Beginning of file
SEEK_CUR Current position of the file pointer
SEEK_END End of file

28. #include <stdio.h> OUTPUT
void main (){
FILE *fp; ; = FILE OPEN IN WRITE MODE
int c,l
fp = fopen("file.txt",“w");
fputs("This is Deepika", fp);
fseek( fp, 7, SEEK_SET );
fputs(" C Programming Language", fp);
fclose(fp); =FILE OPEN IN READ MODE
fp = fopen("file.txt","r");
while(1)
{c = fgetc(fp);
if( feof(fp) ){
break;}
printf("%c", c);}
fp = fopen("file.txt", “a");
fseek(fp, 0, SEEK_END); =THE FILE SIZE IS 30BYTES
l = ftell(fp);
printf("nnnnTotal size of file.txt = %d bytes", l);
fprintf(fp,”nnnTotal size of the file=%d bytes”,l);
fclose(fp);
getch();
}