C Program for the indexed sequential file for the student database

C Program for the indexed sequential file for the student database.

/* C Programs for the indexed sequential file for the student database */

#include <stdio.h>

#include <conio.h>

#include <stdlib.h>  /*standard library function header file */

typedef struct student  /*student is a structure with elements*/

{

      int rno;

      char name[20];

      int age;

      int marks;

}ss;

typedef struct index /* index is a structure with integer *

{

      int irno;

      long offset;

      int flag;

}is;

FILE *ptr= NULL;   /* file pointer NULL */

FILE *iptr=NULL;

void main()

{

      int ch;

      int status;

      int rno;

      char opl='y';

      ptr=fopen("std.dat", "wb");

if(ptr == NULL)

{

      printf("file not found");

      getch();

      exit(0);

} /* if */

iptr=fopen("stdl.dat" "wb");

if(iptr== NULL)

{

      printf("file not found");

      getch();

      exit(0);

} /* if */

fclose(ptr); /* file close function closes a file*/

fclose(iptr);

while((op1= 'y') || (op1 = 'Y'))

{

printf("\n1. Add");

printf("\n2. Delete");

printf("\n3. Modify");

printf("\n4. Search");

printf("\n5. Display");

printf("\n6. Exit\n");

printf("Enter your option (1‒6):");

scanf("%d", &ch);

switch(ch)

{

case 1:

      status = ADD_record();

      if(status == 1)

      printf("Record Successfully Added");

      else

            printf("Record could not be Added");

            break;

case 2:

      printf("Enter the rollno of the record to delete");

      scanf("%d", &rno);

      status=DELETE_RECORD(rno);

      if(status == 1)

      printf("Record deleted successfully");

else

      printf("Record could not be deleted");

      break;

case 3:

      printf("Enter rollno of the record to modify:");

      scanf("%d", &rno);

      status=MODIFY RECORD(rno);

      if(status == 1)

      printf("Record modified successfully");

      else

      printf("Record could not be modified");

      break;

case 4:

      printf("Enter the rollno to search: ");

      scanf("%d", &rno);

      status = SEARCH_RECORD(rno);

      if(status == 1)

      printf("Record found");

      else

      printf("Record not found");

      getch();

      break;

case 5:

      DISPLAY ALL_RECORD();

      break;

case 6:

      exit(0);

} /* switch */

fflush(stdin); /* flush function is used to flush a file */

printf("\nDo You want to continue (Y/N): ");

scanf("%c", &op1);

if((op1 == 'n') || (op1== 'N'))

break;

} /* while */

} /* main */

int ADD RECORD()

{

ss stud;

is ind;

long offset;

ptr=fopen("std.dat", "rb+ ");

if(ptr== NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

while(fread(& stud, sizeof(stud), 1,ptr));

offset=ftell(ptr); /*ftell() is used to specify the position */

printf("Rollno: ");

scanf("%d", &stud. rno);

printf("Name of the student: ");

scanf("%s", & stud.name);

printf("Age: ");

scanf("%d", &stud. age);

printf("Marks: ");

scanf("%d", & stud.marks);

fwrite(&stud, sizeof(stud), 1,ptr); /*fwrite writes data to file*/

fclose(ptr); /* fclose closes a file associated with pointer*/

iptr=fopen("std1.dat", "ab+");

if(iptr== NULL)

       printf("File not opened");

      return ‒1;

} /* if */

ind.irno stud.rno;

ind.offset offset;

ind.flag = 1;

fwrite(&ind, sizeof(ind), 1,iptr);

fclose(iptr);

SORT FILE();

return 1;

} /* ADD RECORD() */

int DELETE RECORD(int_rno)

{

     is ind;

     int flag=0;

     iptr=fopen("std1.dat", "rb + ");

if(iptr== NULL)

{

      printf("File not opened");

      return ‒1;

} /* if */

while (fread(&ind, sizeof(is),1,iptr));

{

      if(ind.irno ==rno)

     {

         flag = 1;

     } /* if */

} /* while */

if(flag==1)

{

ind.flag = ‒1;

fseek(iptr, ‒(long) sizeof(is), SEEK_CUR);

fwrite(&ind, sizeof(is),1,iptr);

fclose(iptr);

return 1;

} /* if */

fclose(iptr);

return ‒1;

} /* DELETE_RECORD() */

int MODIFY RECORD (int rno).

{

is ind;

ss stud;

int flag=0;

iptr=fopen("std1.dat", "rb+ ");

if(iptr== NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

while (fread(&ind, sizeof(is), 1,iptr))

if(ind.irno == rno)

{

       flag=1;

       break;

} /* if */

} /* while */

fclose(iptr); /* file close */

if(flag == 1)

{

         ptr=fopen("std.dat", "rb+ ");   /* file open */

if(ptr == NULL)

{

       printf("File not opened");

       return ‒1;

} /* if */

fseek(ptr, ind.offset, SEEK_SET); /*fseek() position pointer*/

fread(&stud, sizeof(stud), 1,ptr); /*fread() used to read data*/

printf("Enter Name:");

scanf("%s", stud. name);

printf("Age:");

scanf("%d", &stud. age);

printf("Marks: ");

scanf("%d", & stud. marks);

fseek(ptr, (long) sizeof(stud), SEEK CUR);

fwrite(& stud, sizeof(stud), 1,ptr); /* file write */

fclose(ptr); /* file close */

return 1;

} /* if */

return ‒1;

}  /* MODIFY RECORD */

int SEARCH_RECORD(int rno)

{

is ind;

ss stud;

iptr=fopen("stdl.dat", "rb+ ");

if(iptr== NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

while (fread(&ind, sizeof(is), 1,iptr))

{

if(ind.irno ==rno && ind. flag==1)

{

     fclose(iptr);

     return 1;

} /* if */

} /* while */

fclose(iptr); /* file close*/

return ‒1;

} /* SEARCH_RECORD() */

int DISPLAY ALL RECORD()

{

is ind;

ss stud;

iptr=fopen("std1.dat", "rb + ");

if(iptr== NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

ptr=fopen("std.dat", "rb+ ");

if(ptr== NULL)

{

     printf("file not opened");

     return ‒1;

} /* if */

while(fread(&ind, sizeof(is), 1,iptr)) /* file read */

{

if(ind.flag == 1)

{

     fseek(ptr, ind. offset, SEEK_SET);

     fread(&stud, sizeof(stud), 1, ptr); /* file read */

     printf("\n\n Rollno %d", stud.rno);

     printf("\n Name : %s", stud.name);

     printf("\n Age : %d", stud.age);

     printf("\n Marks: %d", stud.marks);

} /* if */

} /* while */

fclose(iptr); /* file close */

fclose(ptr); /* file close */

return 1;

} /* DISPLAY ALL RECORD() */

int SORT FILE()

{

int size;

int i,j,flag=0;

is ind, ind_temp;

ss stud;

iptr=fopen("stdl.dat", "rb + ");

if(iptr == NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

ptr=fopen("std.dat", "rb+ ");

if(ptr= = NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

size=0;

while(fread(&ind, sizeof(is),1,iptr))

size++;

fclose(iptr);

iptr=fopen("std.dat", "rb+");

if(iptr== NULL)

{

     printf("File not opened");

     return ‒1;

} /* if */

for(i=0;i< size;i++)

{

     flag = 0;

     for(j=0;j< size‒(i+1);j++)

     {

     fseek(iptr,j* sizeof(is), SEEK__set);

     fread(&ind, sizeof(is), 1,iptr);

     fread(&ind_temp, sizeof(is), 2, iptr);

          if(ind.irno > ind_temp. irno)

          {

               fseek(ptr,j*sizeof(is), SEEK_SET);

               fwrite(&ind_temp, sizeof(is),1,iptr);

               fseek(iptr, (j+1)*sizeof(is), SEEK_SET);

               fwrite(&ind, sizeof(is),1,iptr);

               flag=1;

          } /*  if  */

     if (flag === 0)

          break;

} /* for */

fclose(iptr);

return 1;

} /* for */

} /* SORT FILE() */

OUTPUT

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):1

Rollno:01

Name of the student: muni

Age:25

Marks:78

Record Successfully Added

Do You want to continue (Y/N): y

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):1

Rollno:02

Name of the student: venkat

Age:24

Marks:67

Record Successfully Added

Do You want to continue (Y/N): y

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):1

Rollno:03

Name of the student: shankar

Age:30

Marks:79

Record Successfully Added

Do You want to continue(Y/N): y

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):2

Enter the rollno of the record to delete 02

Record could not be deleted

Do you want to continue(Y/N): y

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):3

Enter rollno of the record to modify: 3

Enter Name: shankar

Age:30

Marks:89

Record modified successfully

Do You want to continue (Y/N): y

1. Add

2. Delete

3. Modify

4. Search

5. Display

6. Exit

Enter your option (1‒6):5

Rollno : 1

Name: muni

Age : 25

Marks : 78

Rollno: 2

Name: mahi

Age : 24

Marks : 67

Rollno: 3

Name: suma

Age : 30

Marks : 89

Do You want to continue (Y/N):6

EXPLANATION: The structure student and index are declared as global structure. The main function opens the file std.dat. If the file is NULL. Then prints file not found. Then open the file std1.dat if the file is NULL then prints file not found and close the both file pointer. The while loop reads the value of option ch and executes to switch case statement depends upon the user entered value. The ADD_RECORD() function opens the file std.dat and reads stud.no, stud.name, stud.age, stud.marks, and executes the body of the function. The function DELETE_RECORD() executes the body of function and while loop, if statements are executed in the body. This function is used for Delete the items. The MODIFY_RECORD() function executes the body and reads stud.name, stud.age, stud.marks, SEARCH_RECORD() function executes the body and close the file iptr. The DISPLAY_ALL_RECORD() function prints the stud.rno, stud.name, stud.age, stud.marks and closed the file pointer iptr. The SORT_FILE() function used the if statement and for loop structure reads and writes the file and finally used the file prints iptr and terminates the program.