The document discusses file handling in C programming, explaining its importance for data storage, reusability, and portability. It outlines functions like fopen(), fclose(), getc(), and putc(), along with steps for creating file handling routines, including file opening modes. The document also includes example programs demonstrating various file operations such as reading, writing, and copying data between files.

1. Can you C
File Handling
Rohan K.Gajre.
Drop me a line if I can do anything else for you.
rohangajre@gmail.com

2. why we need file handling?
To store the output of a program as well as
• Reusability: It helps in preserving the data or information generated after
running the program.
• Large storage capacity: Using files, you need not worry about the
problem of storing data in bulk.
• Saves time: Certain programs require a lot of input from the user. You can
easily access any part of the code with the help of certain commands.
• Portability: You can easily transfer the contents of a file from one
computer system to another without having to worry about the loss of data.
C Programming has some in build library
functions for same as following
• fopen():- Creating a new file or Opening an existing file in your system.
• fclose() :-Closing a file
• getc() :-Reading character from a line
• putc() :-Writing characters in a file
• fscanf():-Reading a set of data from a file

3. • fprintf():-Writing a set of data in a file
• getw():-Reading an integral value from a file
• putw():-Writing an integral value in a file
• fseek():-Setting a desired position in the file
• ftell():-Getting the current position in the file
• rewind():-Setting the position at the beginning point
• Simply we may say that if you want to save or read your C program output
then use file handling.
Steps for creating file handling
1 create file or open file(fopen())
2 select proper mode of file(r,w,a)
3 close file(fclose())
Common mode of file
• r To open a text file
• w To create or open a file in writing mode
• a To open a file in append mode
• r+ We use it to open a text file in both reading and writing mode
• w+ We use it to open a text file in both reading and writing mode

4. • a+ We use it to open a text file in both reading and writing mode
• rb We use it to open a binary file in reading mode
• wb We use it to open or create a binary file in writing mode
• ab We use it to open a binary file in append mode
• rb+ We use it to open a binary file in both reading and writing mode
• wb+ We use it to open a binary file in both reading and writing mode
• ab+ We use it to open a binary file in both reading and writing mode
1.Creating a file
• First, create your file pointer it as simple as creating a variable this
declaration is needed for communication between file and the program.
Syntax:
FILE *filepointername;
e.g.
FILE *fp;
2.Open a file
• Opening a file is performed using the fopen() defined in stdio.h headfile
Syntax:
Filepointer name=fopen(“filename.txt”,”mode”);
e.g. fp=fopen(“data.txt”,”w”);

5. 3.Close a file
• The file must be closed after reading and writing.use fclose() function with
name of file pointer.
Synatx:
Fclose(filepointer);
e.g.
fclose(*fp);
• Here is a program in C that illustrates the use of file handling.
try it...

6. //Copy contents of one file to another
main()
{
FILE *wfp,*rfp;
char ch;
clrscr();
rfp = fopen("source","r");
wfp = fopen("target","w");
if(wfp==NULL || rfp==NULL)
{
printf("nUnable to open the file
");
getch();
exit();
}
while(!feof(rfp))
{
ch = fgetc(rfp);
fputc(ch,wfp);
}
printf("nCopied the file ");
fclose(wfp);
fclose(rfp);
getch();
return 0;
}

7. //WAP to accept 2 no and print result on file
void main() {
FILE *fp;
int num,i,prod;
clrscr();
fp = fopen("table.dat","w+");
printf("nEnter the integer number ");
scanf("%d",&num);
for(i=1;i<=10;i++) {
printf("n%d * %d = %d",num,i,num*i);
fprintf(fp,"%d %d %dn",num,i,num*i); }
rewind(fp);
getch(); clrscr();
printf("nThe table in the file is nnnn");
while(fscanf(fp,"%d %d %d",&num,&i,&prod)!=EOF)
printf("n%d * %d = %d",num,i,prod);
fclose(fp);
getch();
}

8. //Counting the number of charactrers, words and the lines in the file
main() {
FILE *rfp;
char ch;
int chars=0,words=0,lines=0;
clrscr();
rfp = fopen("source","r");
if(rfp==NULL) {
printf("nUnable to open the file ");
getch();
exit(); }
while(ch!=EOF) {
ch = fgetc(rfp);
if(ch!=' ' && ch!='n')
chars++;

9. else
words++;
if(ch=='n')
lines++; }
printf("nThe number of characters in the file are %d",chars);
printf("nThe number of words in the file are %d",words);
printf("nThe number of lines in the file are %d",lines);
fclose(rfp);
getch();
return 0;
}

10. //Reading the contents of the files
main() {
FILE *rfp;
char ch;
clrscr();
rfp = fopen("source","r");
if(rfp==NULL)
{
printf("nUnable to open the file ");
getch();
exit();
}
printf("nThe contents of the file are n");
while(!feof(rfp))
{
ch = fgetc(rfp);
printf("%c",ch);
}
fclose(rfp);
getch();
return 0; }

11. //Demo of fprintf () function
main()
{
FILE *wfp;
int num1=100,num2 = 200;
clrscr();
wfp = fopen("abc","w");
if(wfp==NULL)
{
printf("nUnable to open the file ");
getch();
}
printf("nThis is the statement on the screen ");
printf("n%d + %d = %d",num1,num2,num1+num2);
fprintf(wfp,"nThis is the statement in the screen");
fprintf(wfp,"n%d + %d = %d",num1,num2,num1+num2);
fclose(wfp);
getch();
return 0;
}

12. //Demo of fputc() function
main() {
FILE *wfp;
char ch;
clrscr();
wfp = fopen("text","w");
if(wfp==NULL)
{
printf("nUnable to open the file ");
getch(); }
printf("nEnter '$' to stop ");
while(1) {
scanf("%c",&ch);
if(ch=='$')
break;
fputc(ch,wfp);
}
fclose(wfp);
getch();
}

13. //Writing the table in file & reading from the file
main() {
FILE *fp;
int num,i,prod;
clrscr();
fp = fopen("table","w");
printf("nEnter the integer number ");
fscanf(stdin,"%d",&num);
for(i=1;i<=10;i++)
{
fprintf(stdout,"n%d * %d = %d",num,i,num*i);
fprintf(fp,"n%d * %d = %d",num,i,num*i);
}
getch();
fclose(fp);
clrscr();
fp = fopen("table","r");
printf("nThe contents of the file are n ");
while(fscanf(fp,"%d %d %d",&num,&i,&prod)!=EOF)
printf("n%d * %d = %d",num,i,prod);
getch(); }

14. //Record operations using the fprintf ()and fscanf () functions
struct student
{
char name[20];
int roll,age;
}S;
main() {
FILE *fp;
struct student S;
char ch;
fp = fopen("Stud.dat","a");
clrscr();
do
{
fprintf(stdout,"nEnter the details of the studemt ");
fscanf(stdin,"%s %d %d",S.name,&S.roll,&S.age);
fprintf(fp,"n%s %d %d",S.name,S.roll,S.age);

15. printf("nCont ..........");
fflush(stdin);
scanf("%c",&ch);
}while(ch=='y');
clrscr();
fclose(fp);
fp = fopen("Stud.dat","r");
printf("nthe details of the student are n");
while(!feof(fp))
{
fscanf(fp,"%s %d %d",S.name,&S.roll,&S.age);
printf("n%s t%d %dn",S.name,S.roll,S.age);
}
getch();
return 0;
}

16. //Concatenating two files in the third file
main()
{
char ch,ch1;
FILE *fp1,*fp2,*fp3;
clrscr();
fp1=fopen("file1","r");
fp2=fopen("file2","r");
fp3=fopen("file3","w");
if(fp1==NULL || fp2==NULL)
{
printf("nUnable to open the file ");
getch();
exit();
}

17. while(ch!=EOF)
{
ch=fgetc(fp1);
fputc(ch,fp3);
}
while(ch1!=EOF)
{
ch1=fgetc(fp2);
fputc(ch1,fp3);
}
fclose(fp1);
fclose(fp2);
fclose(fp3);
printf("n Task done ............. ");
getch();
return 0;
}

18. Thank You………