jq - 拾取后追加元素

Question

系统信息

jq：1.7

选择

• 以下命令按预期正常工作：

jq 'pick(.id,.title,.webpage_url,.channel,.duration_string,.upload_date)' *.info.json

{
  "id": "uO8Sn0Xch1s",
  "title": "A transformative new way of classifying foods 🍔🍕🍟 BBC",
  "webpage_url": "https://www.youtube.com/watch?v=uO8Sn0Xch1s",
  "channel": "BBC",
  "duration_string": "4:19",
  "upload_date": "20210701"
}

选择并追加

$ Date=$(date +%Y-%m-%d)
$ jq 'pick(.id,.title,.webpage_url,.channel,.duration_string,.upload_date)' *.info.json \
  | jq --arg Date="$Date" '. += {"date": $Date}'

{
  "id": "uO8Sn0Xch1s",
  "title": "A transformative new way of classifying foods 🍔🍕🍟 BBC",
  "webpage_url": "https://www.youtube.com/watch?v=uO8Sn0Xch1s",
  "channel": "BBC",
  "duration_string": "4:19",
  "upload_date": "20210701"
}

问题

1. “挑选”和“追加”产生与“挑选”相同的输出，但不追加日期。为什么以及如何纠正这个问题？
2. 还尝试了 + 而不是 +=，两者都不起作用（但应该按照参考文献 2 工作）

预期产出

{
  "id": "uO8Sn0Xch1s",
  "title": "A transformative new way of classifying foods 🍔🍕🍟 BBC",
  "webpage_url": "https://www.youtube.com/watch?v=uO8Sn0Xch1s",
  "channel": "BBC",
  "duration_string": "4:19",
  "upload_date": "20210701",
  "date": "2024-05-10"
}

参考

• 如何使用 jq 命令向 JSON 对象添加字段？ - 堆栈溢出
• 使用 jq 将新元素添加到现有 JSON 数组 - 代码日志

Answer 1

$ Date=$(date +%Y-%m-%d)
$ jq 'pick(.id,.title,.webpage_url,.channel,.duration_string,.upload_date)' *.info.json \
  | jq --arg Date="$Date" '. += {"date": $Date}'

基于上述建议，以下更简洁

jq --arg Date "$Date" 'pick(.id,.title,.webpage_url,.channel,.duration_string,.upload_date) + {"date": $Date}' *.info.json