Module Management

bash

# Initialize module
go mod init github.com/user/project

# Add dependencies
go get github.com/pkg/errors
go get github.com/pkg/errors@v0.9.1    # Specific version
go get github.com/pkg/errors@latest    # Latest

# Tidy dependencies
go mod tidy

# Download dependencies
go mod download

# Vendor dependencies
go mod vendor

# Show dependency graph
go mod graph

# Why is dependency needed?
go mod why github.com/pkg/errors

Building

bash

# Build current package
go build

# Build specific package
go build ./cmd/myapp

# Build with output name
go build -o bin/myapp ./cmd/myapp

# Build for different OS/arch
GOOS=linux GOARCH=amd64 go build -o bin/myapp-linux

# Build with version info
go build -ldflags "-X main.version=1.0.0"

# Install binary
go install ./cmd/myapp

Testing

bash

# Run tests
go test ./...

# Verbose output
go test -v ./...

# Run specific test
go test -run TestName ./...

# With coverage
go test -cover ./...
go test -coverprofile=coverage.out ./...
go tool cover -html=coverage.out

# Race detection
go test -race ./...

# Benchmarks
go test -bench=. ./...
go test -bench=BenchmarkName -benchmem ./...

Code Quality

bash

# Format code
go fmt ./...
gofmt -s -w .              # Simplify

# Vet (static analysis)
go vet ./...

# Generate code
go generate ./...

Other Commands

bash

# Run directly
go run main.go
go run ./cmd/myapp

# List packages
go list ./...
go list -m all             # All modules

# Show documentation
go doc fmt.Println
go doc -all fmt

# Environment
go env
go env GOPATH
go env -w GOPROXY=https://proxy.golang.org,direct

Cross-Compilation Targets

GOOS	GOARCH
linux	amd64, arm64, arm
darwin	amd64, arm64
windows	amd64, arm64
freebsd	amd64