jq从json中选择动态项目

时间:2017-03-02 09:08:43

标签: json bash jq

我有这样的JSON:

{
  "photo_807": "Ih2RnaBTg2o.jpg",
  "photo_604": "zodCm9fQgX8.jpg",
  "photo_130": "4Dx-SUNKBw4.jpg",
  "photo_75": "7COWb8ou1qA.jpg",
  "user_id": 100,
  "owner_id": -2435432542783750,
  "access_key": "fc5275423676514042234324265cc3df7607c",
  "post_id": 380435645368865101,
  "date": 14858616848616779856424245814,
  "text": "",
  "height": 417,
  "width": 740,
  "id": 45624575446886886564368555,
  "album_id": -36
}

我想从输出中得到唯一的Photo值,我想得到这个:

"photo_807": "Ih2RnaBTg2o.jpg"
"photo_604": "zodCm9fQgX8.jpg"
"photo_130": "4Dx-SUNKBw4.jpg"

现在关于我的问题,从下一个JSON文件我将获得具有如下新名称的照片项目:

  "photo_181": "Ih2RnaBTg2o.jpg",
  "photo_583": "zodCm9fQgX8.jpg",
  "photo_975": "4Dx-SUNKBw4.jpg",
  "photo_32": "7COWb8ou1qA.jpg",

如何从动态项目中获取此值photo_ *?

我尝试这样的事情:

  cat  ./json3.txt | jq  '.response.items[].attachments[].photo | select(.photo | startswith("photo"))'

但它不起作用。

当我跑步时:

cat  ./json3.txt | jq  '.response.items[].attachments[].photo'  

我得到了所有项目的输出:

{
  "photo_807": "Ih2RnaBTg2o.jpg",
  "photo_604": "zodCm9fQgX8.jpg",
  "photo_130": "4Dx-SUNKBw4.jpg",
  "photo_75": "7COWb8ou1qA.jpg",
  "user_id": 100,
  "owner_id": -2435432542783750,
  "access_key": "fc5275423676514042234324265cc3df7607c",
  "post_id": 380435645368865101,
  "date": 14858616848616779856424245814,
  "text": "",
  "height": 417,
  "width": 740,
  "id": 45624575446886886564368555,
  "album_id": -36
}

有人可以帮助我吗?

提前致谢!

1 个答案:

答案 0 :(得分:2)

您可以在jq-play上使用jq过滤器,如下所示!

jq '. | to_entries[] | select(.key | startswith("photo")) | "\(.key) :\(.value)"' json
"photo_807 :Ih2RnaBTg2o.jpg"
"photo_604 :zodCm9fQgX8.jpg"
"photo_130 :4Dx-SUNKBw4.jpg"
"photo_75 :7COWb8ou1qA.jpg"

我们的想法是使用内置的to_entries[],它会将您的输入转换为键值对,如下所示。请参阅下面仅使用to_entries[]

的输出
jq '. | to_entries[]' json
{
  "key": "photo_807",
  "value": "Ih2RnaBTg2o.jpg"
}
{
  "key": "photo_604",
  "value": "zodCm9fQgX8.jpg"
}
{
  "key": "photo_130",
  "value": "4Dx-SUNKBw4.jpg"
}
{
  "key": "photo_75",
  "value": "7COWb8ou1qA.jpg"
}
{
  "key": "user_id",
  "value": 100
}
{
  "key": "owner_id",
  "value": -2435432542783750
}
{
  "key": "access_key",
  "value": "fc5275423676514042234324265cc3df7607c"
}
{
  "key": "post_id",
  "value": 380435645368865100
}
{
  "key": "date",
  "value": 14858616848616779000000000000
}
{
  "key": "text",
  "value": ""
}
{
  "key": "height",
  "value": 417
}
{
  "key": "width",
  "value": 740
}
{
  "key": "id",
  "value": 45624575446886885000000000
}
{
  "key": "album_id",
  "value": -36
}

在此输出中,我们使用内置startswith()过滤.key值,该值以字符串photo开头,并打印.key匹配对象的{1}}和.value对。