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JQ JSON Transform Pipeline CLI

Transform JSON on the command line with jq filters, selecting fields, reshaping objects, and aggregating arrays in pipes.

BashCli Tooling

Code

snippet
#!/usr/bin/env bash
set -euo pipefail

# 输入：带元数据的部署状态 JSON
readonly SAMPLE='[
  {"service": "api", "replicas": 3, "healthy": 3, "region": "eu"},
  {"service": "billing", "replicas": 4, "healthy": 2, "region": "eu"},
  {"service": "search", "replicas": 2, "healthy": 2, "region": "na"}
]'

# 字段选择与对象重塑：输出紧凑的行式报告
echo "$SAMPLE" | jq -r '.[]
  | select(.healthy < .replicas)
  | "\(.service) degraded: \(.healthy)/\(.replicas) in \(.region)"'

# 聚合统计：全部副本与亚健康服务数
echo "$SAMPLE" | jq '{
  total_replicas: (map(.replicas) | add),
  degraded: (map(select(.healthy < .replicas)) | length),
  regions: (map(.region) | unique)
}'

# 按区域分组汇总
echo "$SAMPLE" | jq -r 'group_by(.region)[]
  | "\(.[0].region): \(length) 个服务, 共 \(map(.replicas) | add) 副本"'

# 管道组合：先过滤再排序再取字段
echo "$SAMPLE" | jq -r 'sort_by(-(.replicas)) | .[:2] | .[].service'

# 从文件批量提取并输出 CSV 行
echo "$SAMPLE" | jq -r '.[]
  | [.service, (.replicas|tostring), (.healthy|tostring)] | @csv' \
  > status.csv
echo "written: $(wc -l < status.csv) rows"

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