EXAMPLES OF FILE I/O
WAP to print / write rno,sname,cname in student.txt file.
#include<stdio.h>
void main()
{
int rno;
char sname[100],cname[100];
FILE *fp;
fp=fopen(“student.txt”, “w”);
if( fp==NULL )
{
printf(“file error”);
exit(0);
}
printf(“Enter rno,sname, cname”);
scanf(“%d%s%s”,&rno,&sname,&cname);
fprintf(fp,”%d %s %s”,rno,sname,cname);
fclose( fp );
printf(“Data successfully write to student.txt file”);
}
WAP to read rno,sname,cname from student.txt file.
#include<stdio.h>
void main()
{
int rno;
char sname[100],cname[100];
FILE *fp;
fp=fopen(“student.txt”, “r”);
if( fp==NULL )
{
printf(“File error”);
exit(0);
}
fscanf(fp,”%d%s%s”,&rno,&sname,&cname);
printf(“Rno=%d”,rno);
printf(“\nSname=%s”,sname);
printf(“\nCname=%s”,cname);
fclose(fp);
}
Output :
Rno=501
Sname=santosh
Cname=ECE
WAP to read entire information of a file.
#include<stdio.h>
void main()
{
char ch;
FILE *fp;
fp=fopen(“student.txt”, “r”);
if( fp==NULL )
{
printf(“File error”);
exit(0);
}
while( !feof(fp))
{
fscanf(fp, “%c”,&ch);
if( feof(fp))
break;
printf(“%c”,ch);
}
fclose( fp );
}
Output :
501 santosh ECE
WAP to copy one file to another file.
#include<stdio.h>
void main()
{
char ch;
FILE *fp1,*fp2;
fp1=fopen(“student.txt”, “r”);
fp2=fopen(“dup.txt”, “w”);
if( fp1==NULL )
{
printf(“File 1 error”);
exit(0);
}
if( fp2==NULL )
{
printf(“File 2 error”);
exit(0);
}
while( !feof( fp1 ))
{
fscanf(fp1, “%c”,&ch);
fprintf(fp2, “%c”,ch);
}
printf(“Student.txt copied to dup.txt”);
fclose(fp1);
fclose(fp2);
}
Output:
Student.txt copied to dup.txt
WAP to merge 2 files.
#include<stdio.h>
void main()
{
char ch;
FILE *fp1,*fp2,*fp3;
fp1=fopen(“Student.txt”, “r”);
fp2=fopen(“Employee.txt”, “r”);
fp3=fopen(“Merged.txt”, “w”);
if( fp1==NULL )
{
printf(“File 1 error”);
exit(0);
}
if( fp2==NULL )
{
printf(“File 2 Error”);
exit(0);
}
if( fp3==NULL )
{
printf(“File 3 error”);
exit(0);
}
while( !feof(fp1))
{
fscanf(fp1, “%c”,&ch);
fprintf(fp3, “%c”,ch);
}
while( !feof(fp2))
{
fscanf(fp2, “%c”,&ch);
fprintf(fp3, “%c”,ch);
}
fclose(fp1 );
fclose(fp2);
fclose(fp3);
printf(“Student.txt and Employee.txt are merged into Merged.txt”);
}
Output:
Student.txt and Employee.txt are merged into Merged.txt
WAP to separated vowels and consonants of a student.txt file.
#include<stdio.h>
void main()
{
char ch;
FILE *fp1,*fp2,*fp3;
fp1=fopen("Student.txt",”r”);
fp2=fopen(“Vowels.txt”,”w”);
fp3=fopen(“Consonants.txt”,”w”);
if( fp1==NULL )
{
printf(“File 1 error”);
exit(0);
}
if( fp2==NULL )
{
printf(“File 2 Error”);
exit(0);
}
if( fp3==NULL )
{
printf(“File 3 error”);
exit(0);
}
while( !feof(fp1))
{
fscanf(fp1,“%c”,&ch);
if( ch=='a' || ch=='e' ||ch=='i' ||ch=='o'||ch=='u' || ch=='A' ||ch=='E'||ch=='I'||ch=='O'||ch=='U')
fprintf(fp2“%c”,ch);
else
fprintf(fp3,“%c”,ch);
}
fclose(fp1);
fclose(fp2);
fclose(fp3);
printf(“data seperated”);
}
Output:
data seperated