yq-4-53-2

name	yq-4-53-2
description	A skill for using yq v4.x, a lightweight and portable command-line YAML, JSON, XML, INI, Properties, CSV/TSV, HCL, TOML, Base64, and Lua processor with jq-like syntax. Use when reading, writing, transforming, or converting data between these formats from the terminal, scripts, CI/CD pipelines, or Docker containers without needing Python or Node.js dependencies.

yq v4.x

Overview

yq is a lightweight and portable command-line YAML processor written in Go. It uses jq-like syntax but works with YAML files as well as JSON, XML, INI, Properties, CSV/TSV, HCL, TOML, Base64, and Lua. It provides a dependency-free binary for any platform, making it ideal for shell scripts, CI/CD pipelines, and containerized environments.

Under the hood, yq uses go-yaml v3 as the YAML parser, which supports YAML spec 1.2. In YAML 1.2, yes/no are strings, not booleans.

When to Use

• Reading values from YAML, JSON, XML, INI, Properties, CSV, TSV, HCL, TOML, or Lua files
• Updating configuration files in place (-i)
• Converting between formats (YAML to JSON, XML to YAML, CSV to YAML, etc.)
• Merging multiple configuration files together
• Processing multi-document YAML files
• Working with front matter in markdown files (Jekyll, Hugo, etc.)
• Splitting documents into separate files
• Validating YAML files
• Comparing YAML files via normalized diff
• Using in CI/CD pipelines, GitHub Actions, or Docker containers

Quick Reference

# Read a value
yq '.a.b[0].c' file.yaml

# Pipe from STDIN
yq '.a.b[0].c' < file.yaml


yq -i  file.yaml


NAME=mike yq -i  file.yaml


yq -Poy sample.json


yq -n 


yq -n  > newfile.yaml


yq --exit-status  file.yaml > /dev/null