1. go
  2. /standard library

Go Standard Library Overview

The Go standard library is one of the language's greatest strengths, providing a rich set of packages that enable developers to build robust applications without external dependencies. This guide covers the most important packages and their practical applications.

What You'll Learn

  • How to perform IO operations efficiently
  • Working with files and directories
  • Managing time and dates
  • Processing JSON data
  • Using regular expressions
  • Making HTTP requests
  • Building HTTP servers
  • Working with templates

Core Packages Overview

IO Package (io)

The io package provides basic interfaces to I/O primitives:

  • io.Reader and io.Writer interfaces
  • Utility functions for I/O operations
  • Combining readers and writers

File Operations (os)

The os package provides a platform-independent interface to operating system functionality:

  • File creation and manipulation
  • Directory operations
  • Environment variables
  • Process management

Time and Date (time)

The time package provides functionality for measuring and displaying time:

  • Time formatting and parsing
  • Duration calculations
  • Timers and tickers
  • Time zones

JSON Processing (encoding/json)

The encoding/json package implements encoding and decoding of JSON:

  • Marshaling and unmarshaling
  • Custom JSON encoders/decoders
  • Working with streams

Regular Expressions (regexp)

The regexp package implements regular expression search:

  • Pattern matching
  • String replacement
  • Regular expression compilation

HTTP Client (net/http)

The HTTP client functionality:

  • Making HTTP requests
  • Managing cookies
  • Handling redirects
  • Custom transport

HTTP Server (net/http)

Building HTTP servers:

  • Router implementation
  • Handler interface
  • Middleware
  • Static file serving

Templates (text/template & html/template)

Template processing engines:

  • Dynamic content generation
  • HTML escaping
  • Custom functions
  • Nested templates

Best Practices

  1. Error Handling

    • Always check for errors when performing I/O operations
    • Use appropriate error wrapping
    • Implement proper cleanup in defer statements

  2. Resource Management

    • Close files and network connections
    • Use buffered I/O when appropriate
    • Implement proper timeouts

  3. Security

    • Use html/template for HTML content
    • Validate file paths
    • Implement proper input sanitization

Next Steps