c program with binary file

[jhansi]

create a binary file and insert the records and query on those inserted record..
queries are: query based on search by name,search by age and search by designation.


the problem is i have created a binary file but it is not storing records permanently. i am using binary file for the first time. plz help me to know how to store records permanently . sending my code

#include<stdio. h>
#include<conio. h>
#include<string .h>
struct record
{
char name[50];
int age;
char designation[50];
}record ;

void main()
{
char name1[50], ch;
// char name[50];
char designation[50];
int age1,a,age2;
struct record r[1];
FILE *f;
int i,n,j;
clrscr();
f=fopen("c:\\in put.dat","wb");
if(!f)
{
printf("unable to open binary file for reading \n");
return;
}
// fread(&r,sizeof (r),1,f);
fwrite(&r[a],sizeof(r[a]),1,f);
printf("Enter the option:\n 1.data entry:\n 2.query:\n");
scanf("%d",&i);

switch(i)
{
case 1:
{
printf("Enter number of records\n");
scanf("%d",&n);
// printf("enter the name\n");
// fgets(name,50,s tdin);
for(a=1;a <=n; a++)
{

printf("Enter name\n");
scanf("%s",r[a].name);
// fgetc(r[a].name);
//gets(r[a].name,50,f);
printf("Enter age\n");
scanf("%d",&r[a].age);
//fgets(r[a].age,1,stdin)
printf("Enter designation\n") ;
scanf("%s",r[a].designation);
// gets(r[a].designation,50 ,f);
// fprintf(f,"%s %d %s\n", r[a].name,r[a].age,r[a].designation);
}
// fwrite(&r[a],sizeof(r[a]),1,f);
// break;
}
case 2:
{
printf("Enter the option:\n a.search by name:\n b.search by age:\n c.search by designation:\n" );
scanf("%s",&ch) ;
switch(ch)
{
case 'a':
{
printf("\n Enter name\n");
scanf("%s",name 1);
printf("Name\t\ t Age\t\t Designation\t\t \n");
printf("--------------------------------------------\n");
for(i=0;i<=n;i+ +)
{
// if(strcmp(name1 ,r[i].name)==0)
// {
// for(j=0;j<=n;j+ +)
// {

if(strncmp(r[i].name,name1,str len(name1))==0)
{

printf("%s\t\t %d\t\t %s\n", r[i].name,r[i].age,r[i].designation);
}
}

printf("--------------------------------------------\n");

break;
}
case 'b':
{
printf("\n Enter age1\n");
scanf("%d",&age 1);
printf("Enter age2\n");
scanf(" %d",&age2);
printf("Name\t\ t Age\t\t Designation\t\t \n");
printf("--------------------------------------------\n");

for(a=0;a<=n;a+ +)
{
if(r[a].age>=age1 && r[a].age<=age2)
{
printf("%s\t\t% d\t\t%s\n",r[a].name,r[a].age,r[a].designation);
}
// else
// printf("The name is not in the list of records\n");
}
printf("--------------------------------------------\n");
break;
}
case 'c':
{
printf("\n Enter designation\n") ;
scanf("%s",desi gnation);

printf("Name\t\ t Age\t\t Designation\t\t \n");
printf("--------------------------------------------\n");
for(i=0;i<=n;i+ +)
{
if(strncmp(r[i].designation,de signation,strle n(designation)) ==0)
{
printf("%s\t\t %d\t\t%s\n",r[i].name,r[i].age,r[i].designation);
}
}
printf("--------------------------------------------\n");
break;
}
}
// default: printf("invalid choice\n");
// break;
}
}
getch();
}

[weaknessforcats]

You can't read from a file rhat is write-only. I see the "wb" but I don't see where you re-open the file as readable.

[Simonius]

You need to do a fclose so that the file's saved and a new fopen for rb or wb+.