How to get help for a command in Linux?
There are four ways to obtain command help in Linux: First, use --help to view basic usage, which is suitable for quickly understanding common options and parameters of commands; second, use man to view the complete man page, providing detailed command descriptions and examples; third, use info to view structured help, which is suitable for information navigation of complex commands such as gcc and make; fourth, refer to network resources and communities, such as Linux China, Stack Overflow and other platforms to obtain Chinese materials or solve specific problems. It is recommended for beginners to master it step by step from --help and man.
Getting command help in Linux is actually very simple, the key is to know several commonly used methods. In different scenarios, some commands may not have a graphical interface and are operated entirely by typing commands in the terminal. It is particularly important to quickly find help information.

Use --help
to view basic usage
Most Linux commands support the --help
parameter, which displays common usage and options for this command. For example, if you want to know how to use ls
, you can directly enter:
ls --help
You will see it lists various parameters, such as -l
is to display details, -a
is to display hidden files, etc. This method is suitable for quick viewing of basic functions and common options for commands, but the information is usually simple and does not provide much in-depth explanation.

Use man
to view the full manual page
If you need more detailed help, you can use the man
command to view the man page. for example:
man ls
This will open a paged document with a complete description of the commands, including parameters, usage examples, precautions, etc.
Operation skills:

- Press the arrow keys or spaces to turn the page
- Press
/
to search for keywords - Press
q
to exit the manual page
Some commands may not have the corresponding documents installed, and at this time, they may prompt No manual entry for xxx
, so you need to install the corresponding document package, such as man-db
or the corresponding documents of the command.
View structured help with info
(suitable for complex commands)
Some commands (such as gcc
and make
) have a lot of help information, and man
page may not be enough. You can use the info
command at this time:
info make
info
provides more structured help documents, which is a bit like early web navigation, where you can use the arrow keys and enter to jump to different chapters. Although it looks a bit old-school, the information is more systematic for complex commands.
Internet resources and communities are also good helpers
If the local help information is not clear enough, or if you prefer Chinese information, you can also search online. for example:
- Visit Linux Chinese communities (such as Linux China, SegmentFault)
- Search for
命令名linux tutorial
- Check out the discussions about Stack Overflow or Reddit
Sometimes official documentation and community experience can help you get around many pitfalls, especially when you encounter problems with specific distributions.
Basically, each of these methods has applicable scenarios. For beginners, it is recommended to start with --help
and man
. If you use it too much, you will naturally know when to use which one.
The above is the detailed content of How to get help for a command 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)

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

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.

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.

In Linux systems, 1. Use ipa or hostname-I command to view private IP; 2. Use curlifconfig.me or curlipinfo.io/ip to obtain public IP; 3. The desktop version can view private IP through system settings, and the browser can access specific websites to view public IP; 4. Common commands can be set as aliases for quick call. These methods are simple and practical, suitable for IP viewing needs in different scenarios.

Linuxcanrunonmodesthardwarewithspecificminimumrequirements.A1GHzprocessor(x86orx86_64)isneeded,withadual-coreCPUrecommended.RAMshouldbeatleast512MBforcommand-lineuseor2GBfordesktopenvironments.Diskspacerequiresaminimumof5–10GB,though25GBisbetterforad

As a pioneer in the digital world, Bitcoin’s unique code name and underlying technology have always been the focus of people’s attention. Its standard code is BTC, also known as XBT on certain platforms that meet international standards. From a technical point of view, Bitcoin is not a single code style, but a huge and sophisticated open source software project. Its core code is mainly written in C and incorporates cryptography, distributed systems and economics principles, so that anyone can view, review and contribute its code.

To enable PHP containers to support automatic construction, the core lies in configuring the continuous integration (CI) process. 1. Use Dockerfile to define the PHP environment, including basic image, extension installation, dependency management and permission settings; 2. Configure CI/CD tools such as GitLabCI, and define the build, test and deployment stages through the .gitlab-ci.yml file to achieve automatic construction, testing and deployment; 3. Integrate test frameworks such as PHPUnit to ensure that tests are automatically run after code changes; 4. Use automated deployment strategies such as Kubernetes to define deployment configuration through the deployment.yaml file; 5. Optimize Dockerfile and adopt multi-stage construction

The shutdown command of Linux/macOS can be shut down, restarted, and timed operations through parameters. 1. Turn off the machine immediately and use sudoshutdownnow or -h/-P parameters; 2. Use the time or specific time point for the shutdown, cancel the use of -c; 3. Use the -r parameters to restart, support timed restart; 4. Pay attention to the need for sudo permissions, be cautious in remote operation, and avoid data loss.
