Export Formats¶

quellog supports four export formats: JSON, YAML, Markdown, and HTML. All formats support section filtering and --full for comprehensive output.

quellog /var/log/postgresql/*.log --json                # JSON to stdout
quellog /var/log/postgresql/*.log --yaml -o report.yaml # YAML to file
quellog /var/log/postgresql/*.log --md -o report.md     # Markdown to file
quellog /var/log/postgresql/*.log --html                # HTML (auto-named)

Multi-format export¶

Combine flags to produce several files in a single pass — parsing and analysis run only once.

quellog demo.json --html --md            # quellog-demo.html, quellog-demo.md
quellog demo.json --html --md --json     # quellog-demo.html, quellog-demo.md, quellog-demo.json
quellog logs/*.log --html --json         # quellog.html, quellog.json (multi-input)

Default filenames:

Single input: quellog-<stem>.<ext> (stem = basename with the last extension stripped).
Multiple inputs or stdin: quellog.<ext>.

Files are written in the current working directory. -o/--output is rejected when more than one format flag is set — every format goes to its default name. Multi-format is supported only for the full report, not for --sql-detail, --event-detail, --sql-performance, or --sql-overview.

JSON¶

Structured output for automation, scripting, and integration with tools like jq.

quellog /var/log/postgresql/*.log --json
quellog /var/log/postgresql/*.log --json-compact  # Minified
quellog /var/log/postgresql/*.log --json --full    # All sections

Section filtering¶

quellog logs/ --sql-performance --json  # SQL data only
quellog logs/ --summary --events --json # Multiple sections

Section flags control which data is included in all formats, including JSON.

Using with jq¶

# Top 5 slowest queries
quellog logs/ --json | jq '.sql_performance.queries | sort_by(-.max_time_ms) | .[0:5] | .[] | {id, type, max_time_ms}'

# Error count
quellog logs/ --json | jq '.events[] | select(.type == "ERROR") | .count'

# Database list with counts
quellog logs/ --json | jq '.databases | sort_by(-.count) | .[] | "\(.name): \(.count)"'

For complete JSON structure reference, see the output of quellog --json --full.

YAML¶

Same data structure as JSON, serialized as YAML. Ideal for template engines like gomplate.

quellog /var/log/postgresql/*.log --yaml
quellog /var/log/postgresql/*.log --yaml --full

gomplate integration¶

quellog logs/ --yaml --full > data.yaml
gomplate -d report=data.yaml -f template.tmpl -o report.txt

Example template:

PostgreSQL Log Report
=====================
Period: {{ (ds "report").summary.start_date }} to {{ (ds "report").summary.end_date }}
Total entries: {{ (ds "report").summary.total_logs }}

{{- if (ds "report").checkpoints }}
Checkpoints: {{ (ds "report").checkpoints.total_checkpoints }}
{{- end }}

Markdown¶

Documentation-ready reports for wikis, Git repos, or ticketing systems.

quellog /var/log/postgresql/*.log --md
quellog /var/log/postgresql/*.log --md -o report.md
quellog /var/log/postgresql/*.log --md --full

Section filtering¶

quellog logs/ --md --sql-summary      # SQL summary only
quellog logs/ --md --maintenance      # Vacuum/analyze only
quellog logs/ --md --checkpoints      # Checkpoint data only

HTML¶

Standalone, self-contained, interactive reports — charts, drill-down modals, client-side filters, the cost map, and period splitting. These have their own page: HTML Report.

quellog /var/log/postgresql/*.log --html