student.c

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

struct Student {
    int id;
    char name[50];
    int age;
    char grade[10];
};

void addStudent();
void displayStudents();
void searchStudent();
void deleteStudent();
void updateStudent();

int main() {
    int choice;
    while (1) {
        printf("\n===== Student Management System =====\n");
        printf("1. Add Student\n");
        printf("2. Display Students\n");
        printf("3. Search Student\n");
        printf("4. Update Student\n");
        printf("5. Delete Student\n");
        printf("6. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1: addStudent(); break;
            case 2: displayStudents(); break;
            case 3: searchStudent(); break;
            case 4: updateStudent(); break;
            case 5: deleteStudent(); break;
            case 6: exit(0);
            default: printf("Invalid choice! Try again.\n");
        }
    }
    return 0;
}

void addStudent() {
    FILE *fp = fopen("students.dat", "ab");
    struct Student s;
    printf("Enter ID: ");
    scanf("%d", &s.id);
    printf("Enter Name: ");
    getchar();  // clear buffer
    gets(s.name);
    printf("Enter Age: ");
    scanf("%d", &s.age);
    printf("Enter Grade: ");
    scanf("%s", s.grade);
    fwrite(&s, sizeof(s), 1, fp);
    fclose(fp);
    printf("Record added successfully!\n");
}

void displayStudents() {
    FILE *fp = fopen("students.dat", "rb");
    struct Student s;
    if (!fp) {
        printf("No records found!\n");
        return;
    }
    printf("\nID\tName\t\tAge\tGrade\n");
    printf("-------------------------------------\n");
    while (fread(&s, sizeof(s), 1, fp))
        printf("%d\t%-15s\t%d\t%s\n", s.id, s.name, s.age, s.grade);
    fclose(fp);
}

void searchStudent() {
    FILE *fp = fopen("students.dat", "rb");
    struct Student s;
    int id, found = 0;
    printf("Enter ID to search: ");
    scanf("%d", &id);
    while (fread(&s, sizeof(s), 1, fp)) {
        if (s.id == id) {
            printf("Record found!\n");
            printf("ID: %d\nName: %s\nAge: %d\nGrade: %s\n", s.id, s.name, s.age, s.grade);
            found = 1;
            break;
        }
    }
    if (!found) printf("Record not found!\n");
    fclose(fp);
}

void deleteStudent() {
    FILE *fp = fopen("students.dat", "rb");
    FILE *temp = fopen("temp.dat", "wb");
    struct Student s;
    int id, found = 0;
    printf("Enter ID to delete: ");
    scanf("%d", &id);
    while (fread(&s, sizeof(s), 1, fp)) {
        if (s.id != id)
            fwrite(&s, sizeof(s), 1, temp);
        else
            found = 1;
    }
    fclose(fp);
    fclose(temp);
    remove("students.dat");
    rename("temp.dat", "students.dat");
    if (found)
        printf("Record deleted successfully!\n");
    else
        printf("Record not found!\n");
}

void updateStudent() {
    FILE *fp = fopen("students.dat", "rb+");
    struct Student s;
    int id, found = 0;
    printf("Enter ID to update: ");
    scanf("%d", &id);
    while (fread(&s, sizeof(s), 1, fp)) {
        if (s.id == id) {
            printf("Enter new Name: ");
            getchar();
            gets(s.name);
            printf("Enter new Age: ");
            scanf("%d", &s.age);
            printf("Enter new Grade: ");
            scanf("%s", s.grade);
            fseek(fp, -sizeof(s), SEEK_CUR);
            fwrite(&s, sizeof(s), 1, fp);
            found = 1;
            printf("Record updated successfully!\n");
            break;
        }
    }
    if (!found)
        printf("Record not found!\n");
    fclose(fp);
}