Data Processing
data-processing
Process JSON with jq and YAML/TOML with yq. Filter, transform, query structured data efficiently. Triggers on: parse JSON, extract from YAML, query config, Docker Compose, K8s manifests, GitHub Actions workflows, package.json, filter data.
SKILL.md
Full skill instructions
Data Processing
Query, filter, and transform structured data (JSON, YAML, TOML) efficiently from the command line.
Tools
| Tool | Command | Use For |
|---|---|---|
| jq | jq '.key' file.json | JSON processing |
| yq | yq '.key' file.yaml | YAML/TOML processing |
jq Essentials
# Extract single field
jq '.name' package.json
# Extract nested field
jq '.scripts.build' package.json
# Extract from array
jq '.dependencies[0]' package.json
# Extract multiple fields
jq '{name, version}' package.json
# Navigate deeply nested
jq '.data.users[0].profile.email' response.json
# Filter by condition
jq '.users[] | select(.active == true)' data.json
# Transform each element
jq '.users | map({id, name})' data.json
# Count elements
jq '.users | length' data.json
# Raw string output
jq -r '.name' package.json
yq Essentials
# Extract field
yq '.name' config.yaml
# Extract nested
yq '.services.web.image' docker-compose.yml
# List all keys
yq 'keys' config.yaml
# List all service names (Docker Compose)
yq '.services | keys' docker-compose.yml
# Get container images (K8s)
yq '.spec.template.spec.containers[].image' deployment.yaml
# Update value (in-place)
yq -i '.version = "2.0.0"' config.yaml
# TOML to JSON
yq -p toml -o json '.' config.toml
Quick Reference
| Task | jq | yq |
|---|---|---|
| Get field | jq '.key' | yq '.key' |
| Array element | jq '.[0]' | yq '.[0]' |
| Filter array | jq '.[] | select(.x)' | yq '.[] | select(.x)' |
| Transform | jq 'map(.x)' | yq 'map(.x)' |
| Count | jq 'length' | yq 'length' |
| Keys | jq 'keys' | yq 'keys' |
| Pretty print | jq '.' | yq '.' |
| Compact | jq -c | yq -o json -I0 |
| Raw output | jq -r | yq -r |
| In-place edit | - | yq -i |
When to Use
- Reading package.json dependencies
- Parsing Docker Compose configurations
- Analyzing Kubernetes manifests
- Processing GitHub Actions workflows
- Extracting data from API responses
- Filtering large JSON datasets
- Config file manipulation
- Data format conversion
Additional Resources
For complete pattern libraries, load:
./references/jq-patterns.md- Arrays, filtering, transformation, aggregation, output formatting./references/yq-patterns.md- Docker Compose, K8s, GitHub Actions, TOML, YAML modification./references/config-files.md- package.json, tsconfig, eslint/prettier patterns