在shell脚本中读取JSON数据

Question

I have a JSON file containing data about some images:

{
    "imageHeight": 1536,
    "sessionID": "4340cc80cb532ecf106a7077fc2a166cb84e2c21",
    "bottomHeight": 1536,
    "imageID": 1,
    "crops": 0,
    "viewPortHeight": 1296,
    "imageWidth": 2048,
    "topHeight": 194,
    "totalHeight": 4234
}

I wish to process these values in a simple manner in a shell script. I searched online but was not able to find any simple material to understand.

EDIT : What I wish to do with the values ?

I'm using convert (Imagemagick) to process the images. So, the whole workflow is something like. Read the an entry say crop from a line in the json file and then use the value in cropping the image :

convert -crop [image width from json]x[image height from json]+0+[crop value from json] [session_id from json]-[imageID from json].png [sessionID]-[ImageID]-cropped.png

Answer 1

I would recommend using jq . For example, to get the imageHeight , you can use:

jq ".imageHeight" data.json

Output:

1536

---

If you want to store the value in a shell variable use:

variable_name=$(jq ".imageHeight" data.json)

Answer 2

Python-solution

import json
from pprint import pprint
json_data=open('json_file')
data = json.load(json_data)
pprint(data)
data['bottomHeight']

output:

In [28]: pprint(data)
{u'bottomHeight': 1536,
 u'crops': 0,
 u'imageHeight': 1536,
 u'imageID': 1,
 u'imageWidth': 2048,
 u'sessionID': u'4340cc80cb532ecf106a7077fc2a166cb84e2c21',
 u'topHeight': 194,
 u'totalHeight': 4234,
 u'viewPortHeight': 1296}

In [29]: data['bottomHeight']
Out[29]: 1536