


Linux is an open source operating system with multi-user and multi-tasking features. In the Linux system, each user has a unique user ID (User ID, UID for short) to identify himself. UID is a number used to identify a user. Users can access system resources and execution permissions through UID. This article will explore the functions and differences of different user IDs in Linux systems, and provide specific code examples to illustrate.
1. Super user (root user)
In the Linux system, the super user, the root user, has the highest authority and can access all resources in the system and perform all operations. The UID of the root user is 0, which is a special UID reserved for superusers in Linux systems. Normally, the root user can perform system management tasks, install software, modify configuration files, and other operations.
Sample code:
$ sudo su Password: (输入密码) $ id -u 0
2. Ordinary users
In addition to the root user, the Linux system also supports the creation of ordinary users. The UID of ordinary users is usually assigned starting from 1000, and each ordinary user has his own UID. The permissions of ordinary users are restricted by the system administrator, and they cannot perform sensitive operations on the system.
Sample code:
$ id -u testuser 1001
3. System user
In the Linux system, there is also a special type of user, namely the system user. System users are typically used to run system services or programs that do not require logging into the system. The system user's UID is usually less than 1000 and will not appear on the login screen.
Sample code:
$ id -u systemd-resolve 108
4. Switch users
In Linux systems, you can use the su command or sudo command to switch user identities. The su command is used to switch to the account of the specified user, and the sudo command is used to execute the specified command with the permissions of other users.
Sample code:
$ su testuser Password: (输入密码) $ id -u 1001
5. Modify user ID
In Linux systems, you can use the chown command to modify the owner of a file or directory, and you can also use the chgrp command. Modify the group to which a file or directory belongs. By modifying the user ID, you can change the owner of a file or directory.
Sample code:
$ chown testuser:testuser testfile.txt $ ls -l testfile.txt -rw-r--r-- 1 testuser testuser 0 Apr 21 12:00 testfile.txt
In the Linux system, different user IDs have different functions and differences. The root user has the highest authority and can perform any operation; ordinary users are restricted by authority and can only perform limited operations; system users are usually used to run system services; user permissions and access can be managed by switching users, modifying user IDs, etc. control. An in-depth understanding of the functions and differences of different user IDs is very important for the security and management of Linux systems.
The above is the detailed content of Explore the functions and differences of different user IDs in Linux systems. For more information, please follow other related articles on the PHP Chinese website!

有些用户们在使用电脑的时候会创建多个账户,不过也有一些用户们的账户没有权限,这就导致一些操作不能直接的进行操作?那Win11怎么设置用户权限?不清楚的用户们可以来本站看看相关的攻略吧。Win11设置用户权限的方法1、直接通过组合快捷键【win+R】打造运行功能,然后在搜索框中输入【netplwiz】点击确定。3、在打开的属性窗口中,点击上方菜单栏中的组成员。5、会出现一个窗口提示,直接点击【是】进行账户的注销重启即可完成设置。

如何实现PHP的用户登录和权限控制?在开发Web应用程序时,用户登录和权限控制是非常重要的功能之一。通过用户登录,我们可以对用户进行身份验证,并且基于用户的权限进行一系列的操作控制。本文将介绍如何使用PHP实现用户登录和权限控制功能。一、用户登录功能实现用户登录功能是用户验证的第一步,只有通过验证的用户才能进一步进行操作。下面是一个基本的用户登录实现过程:创

1、首先微信中并没有直接解除身份认证的功能,但可以通过注销微信支付将实名认证解除,且解除后还能正常聊天。2、打开微信app,点击右下角的【我】,选择【服务】选项。3、点击【钱包】,找到并点击【支付设置】选项,选择【注销微信支付】。4、当用户满足注销微信支付的条件后,即可根据系统提示进行注销即可。

标题:Node.js开发:用户权限管理功能实现及代码示例摘要:随着Web应用程序和系统的复杂性不断增加,用户权限管理成为一个不可忽视的重要功能。本文将介绍在Node.js开发中如何实现用户权限管理功能,并给出具体的代码示例。引言:Node.js作为一个高效且轻量级的开发平台,拥有广泛的应用场景。在众多Node.js应用开发中,用户权限管理往往是必不可少的功能

如何使用Hyperf框架进行身份认证在现代的Web应用程序中,用户身份认证是一个非常重要的功能。为了保护敏感信息和确保应用程序的安全性,身份认证可以确保只有经过验证的用户才能访问受限资源。Hyperf是一个基于Swoole的高性能PHP框架,提供了很多现代化和高效的功能和工具。在Hyperf框架中,我们可以使用多种方法来实现身份认证,下面将介绍其中两种常用的

如何使用PHP实现基于身份认证的鉴权控制概述:身份认证是保护应用程序数据及功能安全的重要一环。鉴权是验证用户是否有权限访问特定资源的过程。在PHP应用程序中,开发人员可以使用不同的方法来实现基于身份认证的鉴权控制。本文将介绍如何使用PHP实现基于身份认证的鉴权控制,并提供代码示例加以说明。用户认证用户认证是身份认证的基础,常见的用户认证方式有基本身份认证(B

如何使用PHP实现人脸识别和身份认证功能人脸识别技术作为一种生物特征识别技术,近年来得到了广泛应用。它可以通过摄像头拍摄到的人脸图像,进行特征提取和比对,以实现身份认证等功能。在本文中,我们将介绍如何使用PHP实现人脸识别和身份认证功能,并给出代码示例。1.准备工作首先,我们需要一个可以进行人脸识别的库。在PHP中,我们可以使用OpenCV扩

Linux操作系统是一个开源的操作系统,广泛应用于服务器和个人电脑等各种设备上。在使用Linux过程中,经常会遇到"PermissionDenied"(权限被拒绝)的异常。本文将探讨造成该异常的原因,并给出具体的代码示例。Linux中每个文件和目录都有相应的权限设置,用于控制用户对其的读、写和执行权限。权限分为三个等级:用户权限、组权限和其他用户权限。当用


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Dreamweaver Mac version
Visual web development tools

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

Zend Studio 13.0.1
Powerful PHP integrated development environment

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

SublimeText3 English version
Recommended: Win version, supports code prompts!
