What does the sudo command mean in Linux?
Jun 29, 2025 am 12:22 AMSudo stands for "superuser execution" or "alternative user execution" in Linux, which allows authorized users to run programs with permissions of another user (usually root). The reasons for its existence include: 1. Improve security and prevent direct logging into the root account; 2. Reduce errors, because each use requires explicit calls; 3. Convenient logging and auditing; 4. Avoid maintaining the highest permissions for a long time. The usage method is to add sudo before the command that needs to be raised, such as sudo apt update. Common scenarios include installing software, editing system configuration files, restarting services, etc. Regarding permission management, only users who belong to a specific group (such as sudo or wheel) can use sudo. They can be configured through the /etc/sudoers file. It is recommended to use the visudo command to edit it. To give new users sudo permissions, add them to the sudo group and log in again. Notes include: 1. Be cautious to avoid accidentally deleting key files; 2. The sudo session is time-sensitive, usually 5-15 minutes; 3. GUI applications can also use sudo through sudo -i or gksu (outdated).
The sudo
command in Linux stands for "superuser do" or sometimes "substitute user do." It allows a permitted user to run programs with the security privileges of another user, typically the root (administrator) user. This is useful when you need to perform tasks that require elevated permissions but don't want to stay logged in as the root user all the time.

Why sudo Exists
Most modern Linux systems disable direct login to the root account by default for security reasons. Instead, they encourage using sudo
to temporarily gain root privileges. This way:

- Mistakes are less likely because you have to explicitly use
sudo
each time. - Actions taken with elevated rights can be logged and audited.
- You avoid the risk of accidentally running harmonious commands as root.
Using sudo
gives you just enough power to get things done without staying at full power all the time.
How to Use sudo
To use sudo
, simply place it before any command that needs elevated privileges:

sudo apt update
This tells the system to run the apt update
command as the root user.
Some common scenarios where you might need sudo
include:
- Installing or removing software (
apt install package-name
) - Editing system configuration files (
sudo nano /etc/hostname
) - Restarting services (
sudo systemctl restart apache2
)
You'll usually be prompted to enter your own password the first time you use sudo
in a session. After that, it remembers you for a short while (typically 5–15 minutes), so you won't have to keep typing it unless you wait too long between commands.
Who Can Use sudo?
Not everyone on the system can use sudo
—only users who are part of the correct group (usually sudo
or wheel
) can. The list of allowed users and groups is defined in the /etc/sudoers
file.
Editing this file directly is risky, so it's best to use the visudo
command instead:
sudo visudo
This ensures syntax errors won't break your system's ability to handle sudo permissions.
If you're setting up a new user and want to give them sudo access, you'd typically add them to the sudo
group like this:
sudo usermod -aG sudo username
After that, the user may need to log out and back in for the change to take effect.
A Few Things to Keep in Mind
Here are some practical tips about working with sudo
:
- Be careful : Running commands with
sudo
can make big changes to your system. Something likesudo rm -rf /
will destroy your system if typed by mistake. - It doesn't always last forever : As mentioned earlier, the sudo “session” times out after a few minutes. You'll be asked for your password again after that.
- GUI apps can also use sudo : If you're launching a graphic application that needs admin rights, use
sudo -i
to get a root shell first, then launch the app from there—or usegksu
if available (though it's deprecated on many systems now).
That's the basic idea behind sudo
. It's one of those tools you'll find yourself using often once you get comfortable with the terminal. Not complicated, but super important.
The above is the detailed content of What does the sudo command mean in Linux?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

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

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

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

The key to installing dual systems in Linux and Windows is partitioning and boot settings. 1. Preparation includes backing up data and compressing existing partitions to make space; 2. Use Ventoy or Rufus to make Linux boot USB disk, recommend Ubuntu; 3. Select "Coexist with other systems" or manually partition during installation (/at least 20GB, /home remaining space, swap optional); 4. Check the installation of third-party drivers to avoid hardware problems; 5. If you do not enter the Grub boot menu after installation, you can use boot-repair to repair the boot or adjust the BIOS startup sequence. As long as the steps are clear and the operation is done properly, the whole process is not complicated.

The key to enabling EPEL repository is to select the correct installation method according to the system version. First, confirm the system type and version, and use the command cat/etc/os-release to obtain information; second, enable EPEL through dnfinstallepel-release on CentOS/RockyLinux, and the 8 and 9 version commands are the same; third, you need to manually download the corresponding version of the .repo file and install it on RHEL; fourth, you can re-import the GPG key when encountering problems. Note that the old version may not be supported, and you can also consider enabling epel-next to obtain the test package. After completing the above steps, use dnfrepolist to verify that the EPEL repository is successfully added.

Newbie users should first clarify their usage requirements when choosing a Linux distribution. 1. Choose Ubuntu or LinuxMint for daily use; programming and development are suitable for Manjaro or Fedora; use Lubuntu and other lightweight systems for old devices; recommend CentOSStream or Debian to learn the underlying principles. 2. Stability is preferred for UbuntuLTS or Debian; you can choose Arch or Manjaro to pursue new features. 3. In terms of community support, Ubuntu and LinuxMint are rich in resources, and Arch documents are technically oriented. 4. In terms of installation difficulty, Ubuntu and LinuxMint are relatively simple, and Arch is suitable for those with basic needs. It is recommended to try it first and then decide.

The steps to add a new hard disk to the Linux system are as follows: 1. Confirm that the hard disk is recognized and use lsblk or fdisk-l to check; 2. Use fdisk or parted partitions, such as fdisk/dev/sdb and create and save; 3. Format the partition to a file system, such as mkfs.ext4/dev/sdb1; 4. Use the mount command for temporary mounts, such as mount/dev/sdb1/mnt/data; 5. Modify /etc/fstab to achieve automatic mount on the computer, and test the mount first to ensure correctness. Be sure to confirm data security before operation to avoid hardware connection problems.

Have problems uploading files in Google Chrome? This may be annoying, right? Whether you are attaching documents to emails, sharing images on social media, or submitting important files for work or school, a smooth file upload process is crucial. So, it can be frustrating if your file uploads continue to fail in Chrome on Windows PC. If you're not ready to give up your favorite browser, here are some tips for fixes that can't upload files on Windows Google Chrome 1. Start with Universal Repair Before we learn about any advanced troubleshooting tips, it's best to try some of the basic solutions mentioned below. Troubleshooting Internet connection issues: Internet connection

Logs in Linux systems are usually stored in the /var/log directory, which contains a variety of key log files, such as syslog or messages (record system logs), auth.log (record authentication events), kern.log (record kernel messages), dpkg.log or yum.log (record package operations), boot.log (record startup information); log content can be viewed through cat, tail-f or journalctl commands; application logs are often located in subdirectories under /var/log, such as Apache's apache2 or httpd directory, MySQL log files, etc.; at the same time, it is necessary to note that log permissions usually require s

sudo stands for "substituteuserdo" or "superuserdo", allowing users to run commands with permissions of other users (usually root). Its core uses include: 1. Perform system-level operations such as installing software or editing system files; 2. Accessing protected directories or logs; 3. Manage services such as restarting nginx; 4. Modify global settings such as /etc/hosts. When using it, the system will check the /etc/sudoers configuration and verify the user password, provide temporary permissions instead of continuously logging in as root, ensuring security. Best practices include: only when necessary, avoid blindly executing network commands, editing sudoers files with visudo, and considering continuous operations.

To manage Linux user groups, you need to master the operation of viewing, creating, deleting, modifying, and user attribute adjustment. To view user group information, you can use cat/etc/group or getentgroup, use groups [username] or id [username] to view the group to which the user belongs; use groupadd to create a group, and use groupdel to specify the GID; use groupdel to delete empty groups; use usermod-aG to add users to the group, and use usermod-g to modify the main group; use usermod-g to remove users from the group by editing /etc/group or using the vigr command; use groupmod-n (change name) or groupmod-g (change GID) to modify group properties, and remember to update the permissions of relevant files.
