Update and search records in files

[Zhafri As-said]

this is a coding for department system. the requirements are to add, update, search and view all records from a file. so far i've finished with add and view functions. there's a slight problem with the search function. whenever i try to search for the last record in the file..it will appear twice. anyone know how to solve the problem? and if u can kindly help me with the update functions.

#include <stdio.h>
#include <string.h>


void load_menu(void);
void add(void);
void update(void);
void search(void);
void view(void);
struct emp e;
FILE *fp ;
struct emp
{
char id[5];
char name[100];
} ;




int main(int argc, char** argv)


{
    load_menu();
    return 0;
}


void load_menu(void)
    {
    int choice;


    do
    {
        printf("\n*****DEPARTMENT SYSTEM*****\n\n");
        printf("1. Add Records\n");
        printf("2. Update Records\n");
        printf("3. Search Records\n");
        printf("4. View Records\n");
        printf("5. Exit\n\n");
        printf("Choose one:\n");
        scanf("%d",&choice);


        switch(choice)
        {
            case 1: add();
                break;
            case 2: update();
                break;
            case 3: search();
                break;
                case 4: view();
                break;
            case 5: printf("Quitting program!\n");
                system("close");
                break;
            default: printf("Invalid choice!\n");
        }


        } while (choice != 5);
        system("cls");
        }


void add(void)
        {


        system("cls");


        fp = fopen ( "Department System.txt", "a" );
        if( fp == NULL )
        {
                printf("Cannot open file.\n");
                printf("Program stopped.\n");
                system("close");
         }
                printf("\n*****ADD RECORDS*****\n");
                printf("\nEnter Department ID : ");
                scanf("%s",e.id);
                printf("\nEnter Department Name: ");
                scanf("%s",e.name);
                fscanf(fp,"%s %s\n\n",e.id, e.name);
                fprintf(fp,"%s %s\n\n",e.id, e.name);
                fclose(fp);
        return;
        }


void update(void)
{


}


void search(void)
{
    char sid[5];
        system("cls");
        printf("\n*****SEARCH RECORDS*****\n");
        fp = fopen ("Department System.txt", "r");
        printf("\nEnter Department ID : ");
        scanf("%s",sid);


        printf("\nID        Name");
        while(!feof(fp)){
        fscanf(fp,"%s %s",&e.id,&e.name);
        if(strcmp(e.id,sid)==0)
        {
                printf("\n%s      %s ",e.id,e.name);
        }
}
        printf("\n\n");
        fclose(fp);
}






void view (void)
        {


        system("cls");
        printf("\n*****VIEW RECORDS*****\n");
        fp = fopen ( "Department System.txt", "r" ) ;
        if( fp == NULL )
        {
                printf("Cannot open file.\n");
                printf("Program stopped.\n");
                system("close");
         }
        printf("\nID        Name");
        while ( fscanf ( fp, "%s %s ", e.id, &e.name) != EOF )
        printf ( "\n%s      %s", e.id, e.name);
        printf("\n\n");
        fclose ( fp ) ;
        return;
}

[rpet]

while(!feof(fp)) {
        fscanf(fp,"%s %s",&e.id,&e.name);
...

The EOF-flag is not set when the last element was read successfully; it is set when the first read operation has failed. That's why there is an extra call to fscanf() in your program.

You may test the return value of fscanf() to control the loop. The return value is the number of items read. ("%s %s" -> 2 items)

while (fscanf(fp, "%s %s", e.id, e.name) == 2) {

However, you will get a lot of more problems because you have no idea how fscanf() works:

fscanf(fp,"%s %s\n\n",e.id, e.name);
fscanf ( fp, "%s %s ", e.id, &e.name)
fscanf(fp,"%s %s",&e.id,&e.name);

There is only one correct way to call fscanf() here, so two statements are guaranteed to be wrong.

[Zhafri As-said]

yeah you're right....it works. thanks. now i just need to do the function for update. do you have any idea how to do that? i've been trying for a few hours.

[Zhafri As-said]

here is where i got to but i know it is wrong....i just read from online about it and try it out.

void update(void)
{


    char sid[5];
    char ch;
    int nofrec =0;
        system("cls");
        printf("\n*****SEARCH RECORDS*****\n");
        fp = fopen ("Department System.txt", "r");
        printf("\nEnter Department ID : ");
        scanf("%s",sid);


        printf("\nID        Name");
        while (fscanf(fp, "%s %s", e.id, e.name) == 2) {nofrec++;
        if(strcmp(e.id,sid)==0)
        {
                printf("\n%s      %s ",e.id,e.name);
        }


        printf("\nDo you want to update this record? Y or N");
                scanf("%c",&ch);
                fseek(fp, ((nofrec-1)*sizeof(e)), 0);
if(ch=='Y'|| ch=='y')
{
printf("Enter the Department ID : ");
scanf("%s", e.id);
printf("Enter the Department name: ");
scanf("%s", e.name);
fprintf(fp, "id is %s\n", e.id);
fprintf(fp, "name is %s\n", e.name);
printf("Record Modified");
}
}
        printf("\n\n");
        fclose(fp);
}

[Zhafri As-said]

anyone can help me with the coding....i need to get it done by today. please help me kindly.