IMPLEMENTATION OF SEQUENTIAL ACCESS FILE

AIM

            To write a C program to implement sequential access of file

ALGORITHM

Step-1: Start the program

Step-2: Open the student file in writing mode

Step-3: Get the user id, name and marks of the students

Step-4: Close the file and open the file in read mode

Step-5: For the search option, user id is given. If the record is found the details of the  

            Student of the student is displayed else failure will be displayed.

Step-6: The display option gives the entire details of the student

Step-7: End the program in the main function

PROGRAM

#include <stdio.h>

typedef struct

{

 int usn;

 char name[25];

 int m1,m2,m3;

}STD;

STD s;

void display(FILE *);

int search(FILE *,int);

void main()

{

 int i,n,usn_key,opn;

 FILE *fp;

 printf(" How many Records ? ");

 scanf("%d",&n);

 fp=fopen("stud.dat","w");

 for(i=0;i<n;i++)

 {

  printf("Read the Info for Student: %d (uid,name,m1,m2,m3) \n",i+1);

  scanf("%d%s%d%d%d",&s.usn,s.name,&s.m1,&s.m2,&s.m3);

  fwrite(&s,sizeof(s),1,fp);

 }

 fclose(fp);

 fp=fopen("stud.dat","r");

 do

 {

  printf("Press 1- Display\t 2- Search\t 3- Exit\t Your Option?");

  scanf("%d",&opn);

  switch(opn)

  {

  case 1: printf("\n Student Records in the File \n");

  display(fp);

  break;

  case 2: printf(" Read the uid of the student to be searched ?");

  scanf("%d",&usn_key);

  if(search(fp,usn_key))

  {

   printf("Success ! Record found in the file\n");

   printf("%d\t%s\t%d\t%d\t%d\n",s.usn,s.name,s.m1,s.m2,s.m3);

  }

  else

   printf(" Failure!! Record with USN %d not found\n",usn_key);

  break;

  case 3:  printf(" Exit!! Press a key . . .");

  getch();

  break;

  default:  printf(" Invalid Option!!! Try again !!!\n");

  break;

  }

 }while(opn != 3);

 fclose(fp);

}   /* End of main() */

void display(FILE *fp)

{

 rewind(fp);

 while(fread(&s,sizeof(s),1,fp))

  printf("%d\t%s\t%d\t%d\t%d\n",s.usn,s.name,s.m1,s.m2,s.m3);

}

int search(FILE *fp, int usn_key)

{

 rewind(fp);

 while(fread(&s,sizeof(s),1,fp))

  if( s.usn == usn_key) return 1;

 return 0;

}

OUTPUT

How many Records ?4

Read the Info for Student: 1 (uid,name,m1,m2,m3)

5

allen

68

59

40

Read the Info for Student: 2 (uid,name,m1,m2,m3)

2

briane

89

58

49

Read the Info for Student: 3 (uid,name,m1,m2,m3)

44

kernighan

44

69

58

Read the Info for Student: 4 (uid,name,m1,m2,m3)

8

weiss

95

48

69

Press 1- Display         2- Search       3- Exit         Your Option?1

 Student Records in the File

5       allen   68      59      40

2       briane  89      58      49

44      kernighan       44      69      58

8       weiss   95      48      69

Press 1- Display         2- Search       3- Exit         Your Option?2

 Read the uid of the student to be searched ?44

Success ! Record found in the file

44      kernighan       44      69      58

Press 1- Display         2- Search       3- Exit         Your Option?3

 Exit!! Press a key . . .

RESULT: Thus a c program for sequential access file is implemented successfully.