Employee text file; sort into binary file

Steps.

1. Read n employees (name, id, salary) and store them in a text file employee.txt with fprintf().
2. Read the text file back into an array of structures with fscanf().
3. Sort the array in ascending order of salary (bubble sort, swapping whole structures).
4. Write the sorted array to a binary file sorted.dat using fwrite().
5. Read the binary file with fread(). The user gives an employee name; the program displays that employee's details and rank. Assumption: rank is the position in the sorted file, so rank 1 is the lowest salary (the question does not say whether the user gives a name or a rank; searching by name is used here).

#include <stdio.h>
#include <string.h>
#define MAX 100

struct employee {
    char name[30];
    int id;
    float salary;
};

int main(void)
{
    struct employee e[MAX], t;
    FILE *fp;
    int n, i, j, found = 0;
    char key[30];

    /* 1. store details in a text file */
    fp = fopen("employee.txt", "w");
    if (fp == NULL) { printf("Cannot open employee.txt\n"); return 1; }
    printf("How many employees? ");
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        printf("Employee %d (name id salary): ", i + 1);
        scanf("%29s %d %f", t.name, &t.id, &t.salary);
        fprintf(fp, "%s %d %f\n", t.name, t.id, t.salary);
    }
    fclose(fp);

    /* 2. read them back */
    fp = fopen("employee.txt", "r");
    if (fp == NULL) { printf("Cannot open employee.txt\n"); return 1; }
    for (i = 0; i < n; i++)
        fscanf(fp, "%29s %d %f", e[i].name, &e[i].id, &e[i].salary);
    fclose(fp);

    /* 3. sort by salary (ascending) */
    for (i = 0; i < n - 1; i++)
        for (j = 0; j < n - 1 - i; j++)
            if (e[j].salary > e[j + 1].salary) {
                t = e[j]; e[j] = e[j + 1]; e[j + 1] = t;
            }

    /* 4. store sorted records in a binary file */
    fp = fopen("sorted.dat", "wb");
    if (fp == NULL) { printf("Cannot open sorted.dat\n"); return 1; }
    fwrite(e, sizeof(struct employee), n, fp);
    fclose(fp);

    /* 5. read the binary file and show details and rank of a given employee */
    fp = fopen("sorted.dat", "rb");
    if (fp == NULL) { printf("Cannot open sorted.dat\n"); return 1; }
    printf("Enter name of employee: ");
    scanf("%29s", key);
    for (i = 1; fread(&t, sizeof t, 1, fp) == 1; i++)
        if (strcmp(t.name, key) == 0) {
            printf("Name: %s  ID: %d  Salary: %.2f  Rank: %d of %d\n",
                   t.name, t.id, t.salary, i, n);
            found = 1;
        }
    if (!found) printf("Employee not found\n");
    fclose(fp);
    return 0;
}

Sample run (Hari earns the highest salary of the four)

Input: 4 Ram 101 45000 Sita 102 32000 Hari 103 58000 Gita 104 39000 Hari

How many employees? Employee 1 (name id salary): Employee 2 (name id salary): Employee 3 (name id salary): Employee 4 (name id salary): Enter name of employee: Name: Hari  ID: 103  Salary: 58000.00  Rank: 4 of 4