如何使用C/C++创建linux用户？

#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
#include <stdio.h>

int main() {
    const char* username = "newuser";
    const char* password = "password";
    uid_t uid;
    gid_t gid;
    const char* homedir = "/home/newuser";
    const char* shell = "/bin/bash";

    // 创建用户
    if (getpwnam(username) != NULL) {
        printf("用户已存在\n");
        return 1;
    }

    uid = getuid();
    gid = getgid();

    if (setuid(0) != 0) {
        printf("无法获取root权限\n");
        return 1;
    }

    if (setgid(0) != 0) {
        printf("无法获取root权限\n");
        return 1;
    }

    if (setuid(uid) != 0) {
        printf("无法恢复用户权限\n");
        return 1;
    }

    if (setgid(gid) != 0) {
        printf("无法恢复用户权限\n");
        return 1;
    }

    if (system("useradd -m -d /home/newuser -s /bin/bash newuser") != 0) {
        printf("创建用户失败\n");
        return 1;
    }

    // 设置密码
    char command[100];
    sprintf(command, "echo newuser:password | chpasswd");
    if (system(command) != 0) {
        printf("设置密码失败\n");
        return 1;
    }

    // 设置用户目录权限
    sprintf(command, "chown -R newuser:newuser /home/newuser");
    if (system(command) != 0) {
        printf("设置用户目录权限失败\n");
        return 1;
    }

    // 设置shell
    sprintf(command, "usermod -s /bin/bash newuser");
    if (system(command) != 0) {
        printf("设置shell失败\n");
        return 1;
    }

    printf("用户创建成功\n");

    return 0;
}