glazed

glazed - A framework for building powerful CLI applications

Add the icing to your structured data!

Glazed is a comprehensive Go framework for building command-line applications that handle structured data elegantly. It provides a rich command system, flexible parameter management, multiple output formats, and an integrated help system.

The framework implements ideas from 14 great tips to make amazing command line applications and focuses on making CLI development both powerful and developer-friendly.

Core Features

Rich Output Formats

Output structured data in multiple formats with automatic field flattening, filtering, and transformation:

Tables: Human-readable ASCII tables and Markdown format

❯ glaze json misc/test-data/*.json
+-----+-----+------------+-----+-----+
| a   | b   | c          | d.e | d.f |
+-----+-----+------------+-----+-----+
| 1   | 2   | [3 4 5]    | 6   | 7   |
| 10  | 20  | [30 40 50] | 60  | 70  |
| 100 | 200 | [300]      |     |     |
+-----+-----+------------+-----+-----+

JSON/YAML: Structured data with optional flattening

❯ glaze json misc/test-data/2.json --output json
[
  {
    "a": 10,
    "b": 20,
    "c": [30, 40, 50],
    "d": {
      "e": 60,
      "f": 70
    }
  }
]

CSV/TSV: Spreadsheet-compatible output

❯ glaze json misc/test-data/*.json --output csv
a,b,c,d.e,d.f
1,2,[3 4 5],6,7
10,20,[30 40 50],60,70
100,200,[300],,

Templates: Go template support for custom formatting

❯ glaze json misc/test-data/*.json --template '{{.a}}-{{.b}}: {{.d.f}}'
+---------------------+
| _0                  |
+---------------------+
| 1-2: 7              |
| 10-20: 70           |
| 100-200: <no value> |
+---------------------+

Flexible Command System

Build CLI applications with multiple command types and output modes:

• BareCommand: Simple commands with custom output handling
• WriterCommand: Commands that write to any io.Writer
• GlazeCommand: Commands producing structured data
• Dual Commands: Support both classic and structured output modes

Parameter Layer System

Organize command parameters into reusable, composable layers:

• Logical grouping (database, logging, output, etc.)
• Multiple configuration sources (CLI, files, environment)
• Type-safe parameter extraction
• Built-in validation and help generation

Integrated Help System

Rich, searchable documentation system with Markdown support:

• Topic-based organization
• Interactive help browsing
• Embedded documentation
• Context-sensitive help

Building Commands

Glazed provides three main command interfaces for different use cases:

BareCommand

Simple commands that handle their own output:

type MyCommand struct {
    *cmds.CommandDescription
}

func (c *MyCommand) Run(ctx context.Context, parsedLayers *layers.ParsedLayers) error {
    fmt.Println("Hello, World!")
    return nil
}

GlazeCommand

Commands that produce structured data output:

func (c *MyCommand) RunIntoGlazeProcessor(
    ctx context.Context,
    parsedLayers *layers.ParsedLayers,
    gp middlewares.Processor,
) error {
    row := types.NewRow(
        types.MRP("name", "John"),
        types.MRP("age", 30),
    )
    return gp.AddRow(ctx, row)
}

Dual Commands

Commands supporting both classic and structured output modes:

// Use the dual command builder for Cobra integration
cobraCmd, err := cli.BuildCobraCommandDualMode(
    myDualCommand,
    cli.WithGlazeToggleFlag("with-glaze-output"),
)

Parameter Layers

Organize command parameters into logical, reusable groups:

// Define layers for different concerns
func NewDatabaseLayer() *layers.ParameterLayer {
    return layers.NewParameterLayer("database", "Database configuration",
        parameters.NewParameterDefinition("host", parameters.ParameterTypeString,
            parameters.WithDefault("localhost")),
        parameters.NewParameterDefinition("port", parameters.ParameterTypeInteger,
            parameters.WithDefault(5432)),
    )
}

// Use layers in command definitions
cmd := cmds.NewCommandDescription("mycommand",
    cmds.WithLayersList(
        databaseLayer,
        loggingLayer, 
        glazedLayer,
    ),
)

Benefits:

• Reuse common parameter sets across commands
• Avoid parameter naming conflicts with prefixes
• Type-safe parameter extraction with structs
• Built-in validation and help generation

Help System

Create rich, searchable documentation with Markdown files:

// Embed documentation
//go:embed doc/*
var docFS embed.FS

func AddDocToHelpSystem(helpSystem *help.HelpSystem) error {
    return helpSystem.LoadSectionsFromFS(docFS, "doc")
}

Markdown structure:

---
Title: Command Usage Guide
Slug: command-usage
Short: Learn how to use commands effectively
Topics: [commands, usage]
SectionType: Tutorial
---

# Command Usage Content
Your documentation content here...

Installation

Installing the Framework

To use Glazed as a library in your Go project:

go get github.com/go-go-golems/glazed

Installing the glaze CLI Tool

Using Homebrew:

brew tap go-go-golems/go-go-go
brew install go-go-golems/go-go-go/glazed

Using apt-get:

echo "deb [trusted=yes] https://apt.fury.io/go-go-golems/ /" >> /etc/apt/sources.list.d/fury.list
apt-get update
apt-get install glazed

Using yum:

echo "
[fury]
name=Gemfury Private Repo
baseurl=https://yum.fury.io/go-go-golems/
enabled=1
gpgcheck=0
" >> /etc/yum.repos.d/fury.repo
yum install glazed

Using go install:

go install github.com/go-go-golems/glazed/cmd/glaze@latest

Download binaries from GitHub Releases

Or run from source:

go run ./cmd/glaze

Quick Start

1. Create a command:

cmd, err := NewMyGlazeCommand()
cobraCmd, err := cli.BuildCobraCommandFromGlazeCommand(cmd)

1. Add to your CLI:

rootCmd.AddCommand(cobraCmd)

1. Run with multiple output formats:

myapp command --output json
myapp command --output table --fields name,status
myapp command --output csv > data.csv

Documentation

For comprehensive guides and API references, see:

• Commands Reference - Complete command system guide
• Parameter Layers Guide - Layer system with examples
• Writing Help Entries - Help system documentation

Examples

See the cmd/examples directory for working examples including:

• Basic command types
• Dual command implementations
• Parameter layer usage
• Help system integration