[ Linux Command Encyclopaedia](#)
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info is a powerful documentation reader in Linux systems, providing more detailed and structured help documents than the man command. info documents use hypertext links to organize content, making them especially suitable for browsing complex software documentation.
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## Differences Between info and man
| Feature | info Command | man Command |
| --- | --- | --- |
| Document Structure | Hypertext links, hierarchical | Linear text, single page display |
| Content Depth | More detailed, includes tutorials and examples | Concise, mainly reference manual |
| Navigation | Supports node jumping and search | Can only scroll up and down |
| Use Cases | Complex software (GCC, Emacs, etc.) documentation | Quick command usage lookup |
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## Basic Syntax
info [menu item...]
### Common Options
| Option | Description |
| --- | --- |
| `-a` | Use all matching documents |
| `-d` | Add directory to INFOPATH |
| `-f` | Specify the info file to access |
| `-n` | Specify the first node to access |
| `-o` | Output to specified file |
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## Using the info System
### Starting info
info
Running without parameters displays the top-level directory of the info system.
### Viewing Documentation for a Specific Command
info coreutils
This opens the GNU coreutils documentation.
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## Navigation Commands
After entering the info interface, you can use the following shortcuts for navigation:
### Basic Navigation
| Shortcut | Function |
| --- | --- |
| `h` | Display help |
| `?` | Display command summary |
| `q` | Exit info |
| `SPACE` | Page down |
| `DEL` | Page up |
### Node Navigation
| Shortcut | Function |
| --- | --- |
| `n` | Next node |
| `p` | Previous node |
| `u` | Go up one level |
| `m` | Select menu item |
| `l` | Return to previously viewed node |
### Search Functions
| Shortcut | Function |
| --- | --- |
| `s` | Search |
| `i` | Index search |
| `,` | Find next match |
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## Practical Examples
### Example 1: Viewing info Documentation for ls Command
info ls
This displays detailed documentation for the ls command, including:
* Command syntax
* All option descriptions
* Usage examples
* Related command links
### Example 2: Searching for Specific Content in Documentation
1. Open the info document
2. Press `s` key
3. Enter search term such as "permission"
4. Press Enter to start searching
5. Use `,` to find next match
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## Creating Custom info Documents
### 1. Write texinfo File
input texinfo
@setfilename mycommand.info
@settitle My Command Manual
@node Top
@top My Command
This is the top node of my command documentation.
@menu
* Introduction:: Introduction to my command.
* Usage:: How to use my command.
@end menu
@node Introduction
@chapter Introduction
This command does something useful.
@node Usage
@chapter Usage
Here's how to use it...
### 2. Compile to info Format
makeinfo mycommand.texi
### 3. Install info Document
install-info mycommand.info /usr/share/info/dir
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## Advanced Tips
### Viewing info in Emacs
Emacs has a built-in powerful info browser:
M-x info
### Printing info Document
info --subnodes -o output.txt bash
### Setting Default info Browser
export INFO_COMMAND="pinfo"
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## Frequently Asked Questions
### Q: Why do some commands not have info documentation?
A: Not all software provides info format documentation. Traditional Unix commands typically only have man pages.
### Q: How to update the info database?
A: Running `sudo update-info-dir` can update the info directory database.
### Q: Where are info documents stored?
A: They are usually stored in the `/usr/share/info/` directory, in `.info.gz` format.
* * Linux Command Encyclopaedia](#)
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