C语言写出以下系统的代码:系统要求能实现以下基本功能：录入员工信息、更新员工信息、查询员工信 息，排烈员工信息，统计员工信息和输出员工信息等 1. 录入员工信息：从键盘录入表示员工信息的结构体数组各项数据，并将结构 体数组的内容写入表示员工信息的文件中。 2. 更新员工信息：可以实现多次向数据文件追加员工记录的功能，添加完毕后 返回主菜单；能够实现根据员工工号删除文件中员工信息的操作，且可多次删除 记录：可以实现根据员工工号修改员工信息的功能，其中员工信息包括：工号、 姓名、年龄、工作、性别、地址、电话、入职时间，并将最终数据存储到文件中。 3. 查询员工信息：可分别根据姓名、年龄、工作对员工信息进行查询。 4. 排列员工信息：可根据年龄从小到大的顺序对员工信息进行排序。 5. 统计员工信息：能够根据员工的年龄、工作和性别统计显示满足要求的所有 员工信息。 6. 输出员工信息：将员工信息文件中的数据输出到显示器上。 7.实现输入数字0则退出管理系统。

下面是 C 语言实现员工信息管理系统的代码：

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

#define MAX_EMPLOYEES 100

typedef struct {
    char id[20];
    char name[20];
    int age;
    char job[20];
    char gender[10];
    char address[50];
    char phone[20];
    char hire_date[20];
} Employee;

Employee employees[MAX_EMPLOYEES];
int num_employees = 0;

void add_employee() {
    Employee e;
    printf("Enter employee ID: ");
    scanf("%s", e.id);
    printf("Enter employee name: ");
    scanf("%s", e.name);
    printf("Enter employee age: ");
    scanf("%d", &e.age);
    printf("Enter employee job: ");
    scanf("%s", e.job);
    printf("Enter employee gender: ");
    scanf("%s", e.gender);
    printf("Enter employee address: ");
    scanf("%s", e.address);
    printf("Enter employee phone: ");
    scanf("%s", e.phone);
    printf("Enter employee hire date: ");
    scanf("%s", e.hire_date);
    
    employees[num_employees++] = e;
    FILE *fp = fopen("employees.dat", "ab");
    fwrite(&e, sizeof(Employee), 1, fp);
    fclose(fp);
}

void update_employee() {
    char id[20];
    printf("Enter employee ID: ");
    scanf("%s", id);
    
    FILE *fp = fopen("employees.dat", "rb+");
    Employee e;
    while (fread(&e, sizeof(Employee), 1, fp) == 1) {
        if (strcmp(e.id, id) == 0) {
            printf("Enter employee name: ");
            scanf("%s", e.name);
            printf("Enter employee age: ");
            scanf("%d", &e.age);
            printf("Enter employee job: ");
            scanf("%s", e.job);
            printf("Enter employee gender: ");
            scanf("%s", e.gender);
            printf("Enter employee address: ");
            scanf("%s", e.address);
            printf("Enter employee phone: ");
            scanf("%s", e.phone);
            printf("Enter employee hire date: ");
            scanf("%s", e.hire_date);
            
            fseek(fp, -sizeof(Employee), SEEK_CUR);
            fwrite(&e, sizeof(Employee), 1, fp);
            break;
        }
    }
    fclose(fp);
}

void delete_employee() {
    char id[20];
    printf("Enter employee ID: ");
    scanf("%s", id);
    
    FILE *fp = fopen("employees.dat", "rb+");
    Employee e;
    while (fread(&e, sizeof(Employee), 1, fp) == 1) {
        if (strcmp(e.id, id) == 0) {
            fseek(fp, -sizeof(Employee), SEEK_CUR);
            Employee empty = {"", "", 0, "", "", "", "", ""};
            fwrite(&empty, sizeof(Employee), 1, fp);
            break;
        }
    }
    fclose(fp);
}

void sort_employees() {
    int i, j;
    for (i = 0; i < num_employees - 1; i++) {
        for (j = 0; j < num_employees - i - 1; j++) {
            if (employees[j].age > employees[j+1].age) {
                Employee temp = employees[j];
                employees[j] = employees[j+1];
                employees[j+1] = temp;
            }
        }
    }
}

void search_employees() {
    int option;
    printf("Search employees by:\n");
    printf("1. Name\n");
    printf("2. Age\n");
    printf("3. Job\n");
    printf("Enter option: ");
    scanf("%d", &option);
    
    switch (option) {
        case 1: {
            char name[20];
            printf("Enter employee name: ");
            scanf("%s", name);
            int i;
            for (i = 0; i < num_employees; i++) {
                if (strcmp(employees[i].name, name) == 0) {
                    printf("%s\t%s\t%d\t%s\t%s\t%s\t%s\t%s\n",
                           employees[i].id, employees[i].name, employees[i].age,
                           employees[i].job, employees[i].gender, employees[i].address,
                           employees[i].phone, employees[i].hire_date);
                }
            }
            break;
        }
        case 2: {
            int age;
            printf("Enter employee age: ");
            scanf("%d", &age);
            int i;
            for (i = 0; i < num_employees; i++) {
                if (employees[i].age == age) {
                    printf("%s\t%s\t%d\t%s\t%s\t%s\t%s\t%s\n",
                           employees[i].id, employees[i].name, employees[i].age,
                           employees[i].job, employees[i].gender, employees[i].address,
                           employees[i].phone, employees[i].hire_date);
                }
            }
            break;
        }
        case 3: {
            char job[20];
            printf("Enter employee job: ");
            scanf("%s", job);
            int i;
            for (i = 0; i < num_employees; i++) {
                if (strcmp(employees[i].job, job) == 0) {
                    printf("%s\t%s\t%d\t%s\t%s\t%s\t%s\t%s\n",
                           employees[i].id, employees[i].name, employees[i].age,
                           employees[i].job, employees[i].gender, employees[i].address,
                           employees[i].phone, employees[i].hire_date);
                }
            }
            break;
        }
        default:
            break;
    }
}

void count_employees() {
    char age[10], job[20], gender[10];
    printf("Enter age: ");
    scanf("%s", age);
    printf("Enter job: ");
    scanf("%s", job);
    printf("Enter gender: ");
    scanf("%s", gender);
    
    int i, count = 0;
    for (i = 0; i < num_employees; i++) {
        if (strcmp(employees[i].age, age) == 0 &&
            strcmp(employees[i].job, job) == 0 &&
            strcmp(employees[i].gender, gender) == 0) {
            count++;
        }
    }
    printf("Number of employees: %d\n", count);
}

void display_employees() {
    FILE *fp = fopen("employees.dat", "rb");
    Employee e;
    printf("ID\tName\tAge\tJob\tGender\tAddress\tPhone\tHire Date\n");
    while (fread(&e, sizeof(Employee), 1, fp) == 1) {
        if (strlen(e.id) > 0) {
            printf("%s\t%s\t%d\t%s\t%s\t%s\t%s\t%s\n",
                   e.id, e.name, e.age, e.job, e.gender, e.address, e.phone, e.hire_date);
        }
    }
    fclose(fp);
}

void menu() {
    printf("Employee Management System\n");
    printf("1. Add employee\n");
    printf("2. Update employee\n");
    printf("3. Delete employee\n");
    printf("4. Search employee\n");
    printf("5. Sort employees\n");
    printf("6. Count employees\n");
    printf("7. Display employees\n");
    printf("0. Exit\n");
}

int main() {
    int option;
    FILE *fp = fopen("employees.dat", "rb");
    if (fp == NULL) {
        fp = fopen("employees.dat", "wb");
        fclose(fp);
    } else {
        Employee e;
        while (fread(&e, sizeof(Employee), 1, fp) == 1) {
            if (strlen(e.id) > 0) {
                employees[num_employees++] = e;
            }
        }
        fclose(fp);
    }
    
    do {
        menu();
        printf("Enter option: ");
        scanf("%d", &option);
        switch (option) {
            case 1:
                add_employee();
                break;
            case 2:
                update_employee();
                break;
            case 3:
                delete_employee();
                break;
            case 4:
                search_employees();
                break;
            case 5:
                sort_employees();
                break;
            case 6:
                count_employees();
                break;
            case 7:
                display_employees();
                break;
            default:
                break;
        }
    } while (option != 0);
    
    return 0;
}