Introduction and examples of common configuration file formats INI/XML/YAML/JSON/Properties/TOML/HCL/YAML Front Matter/.env

1. Introduction to common configuration files INI XML YAML JSON Properties

Here is a comparison of common configuration file formats (INI, XML, YAML, JSON, Properties, TOML, HCL, YAML Front Matter, .env):

Configuration file format	Introduction	Grammar definition	advantage	shortcoming	Common usage scenarios	Common programming languages
THIS	Simple text file format	Sections and key-value pairs	Simple to understand, easy to edit and maintain	Limited support for complex data structures and nested hierarchies	Store simple configuration information	Python, Java, C#
XML	Markup language for storing and transmitting data	Tags and attributes	Self-describing and extensible, supporting complex data structures and namespaces	The syntax is verbose, the file size is large, and the parsing and processing speed is slow.	Cross-platform and cross-language data exchange	Java, C#, JavaScript
YAML	Human-readable data serialization format	Indentation and structured key-value pairs	Concise syntax and legibility, supports comments and citations	Relatively limited representation of some complex data structures	Configuration files and data serialization	Python, Ruby, JavaScript
JSON	Lightweight data exchange format	Curly brackets represent objects, square brackets represent arrays, and keys and string values ​​need to be enclosed in double quotes.	Concise syntax and extensive support for easy parsing and processing	Comments are not supported and may be a bit verbose compared to other formats	Front-end and back-end data transmission, API interaction	JavaScript, Python, Java
Properties	Simple key-value file format	Key-value pairs, separated by equal sign or colon	Simple to understand, easy to parse and process	Limited support for complex data structures and nested hierarchies	Store simple configuration information	Java
TOML	Profile-oriented language	Key-value pairs and tables (Table)	Concise and easy to read, supports comments and multiple data types	Relatively new, support may be slightly lower	Configuration files and data serialization	Rust, Go, Python
HCL	Configuration language developed by HashiCorp	Blocks and key-value pairs	Concise and easy to read, supports complex data structures and nesting	Relatively new, usage scenarios are relatively limited	Infrastructure automation and cloud environment management	Terraform
YAML Front Matter	YAML format metadata block embedded at the beginning of the file, commonly used in static website generators	YAML syntax	Flexible and easy to read, easy to manage website metadata	Only suitable for specific scenarios	static website generator	Jekyll, Hugo, Gatsby
.env	Simple text file used to store environment variable configuration	Key-value pairs, separated by equal sign or colon	Simple and easy to understand, easy to manage environment variables	Not suitable for complex configuration requirements	Environment variable configuration	Node.js, Python, Ruby, Go, Java

Each configuration file format has its specific advantages and applicable scenarios. You can choose the appropriate configuration file format and programming language based on your project needs and personal preferences. Please note that each configuration file format has its applicable scenarios and advantages and disadvantages. The final choice should be based on your specific needs, programming language and tool support, and file readability and ease of maintenance.

2. Specific examples of configuration file format:

1. INI file format:

; Sample INI configuration file

[Section1]
key1 = value1
key2 = value2

[Section2]
key3 = value3
key4 = value4

2. XML file format:

<!-- Sample XML configuration file -->

<config>
  <section1>
    <key1>value1</key1>
    <key2>value2</key2>
  </section1>
  <section2>
    <key3>value3</key3>
    <key4>value4</key4>
  </section2>
</config>

3. YAML file format:

# Sample YAML configuration file

section1:
  key1: value1
  key2: value2

section2:
  key3: value3
  key4: value4

4. JSON file format:

{
    
    
  "section1": {
    
    
    "key1": "value1",
    "key2": "value2"
  },
  "section2": {
    
    
    "key3": "value3",
    "key4": "value4"
  }
}

5. Properties file format:

# Sample properties configuration file

key1=value1
key2=value2
key3=value3
key4=value4

6. TOML file format:

# Sample TOML configuration file

[section1]
key1 = "value1"
key2 = "value2"

[section2]
key3 = "value3"
key4 = "value4"

7. HCL file format (HashiCorp Configuration Language):

# Sample HCL configuration file

section1 {
  key1 = "value1"
  key2 = "value2"
}

section2 {
  key3 = "value3"
  key4 = "value4"
}

8. YAML Front Matter file format (commonly used for configuration in static website generators):

---
title: "My Website"
author: "John Doe"
description: "This is a sample website"
---

# Content goes here...

9. .env file format (commonly used to store environment variable configuration):

# Sample .env configuration file

API_KEY=abc123
DATABASE_URL=postgres://user:password@localhost/mydb

These are specific examples of common configuration file formats. They are widely used in different application scenarios, and the specific choice depends on the requirements and the tool, framework or language used.