CODEWITHSUNDEEP
pythonjsonbashcurl
NorTicUs
NorTicUs

Reputation: 752

JSON from curl as a function parameter

I'm trying to use an API with curl, returning a JSON:

response=$(curl -i --user api:$APIKey --data-binary @$target https://api.tinypng.com/shrink)

Next, I try to parse (briefly) the response with a function:

parseJson(){
    result="$1"
    result=($(echo $result | python -mjson.tool))
    result=${result%\"*}
    result=${result##*\"}
    return $result
}

and I'm calling it like this: message=$(parseJson "$response" message). FYI, the response is on multiple lines.

But weird thing happened: python gave me No JSON object could be decoded, but if I echoed $result there is a good JSON string. Weirder, if I echoed it before calling python, it looks like python is executed first anyway.

Is there some asynchronous trick ? Why can't I pass my variable string to python ?

Any help or better method will be greatly appreciated!

Upvotes: 1

Views: 667

Answers (2)

ezdazuzena
ezdazuzena

Reputation: 6770

You can try HttpConnection instead of calling curl and do everything directly in python:

conn = httplib.HTTPConnection('www.a_url.com')
conn.request("GET", /index.html')
response = conn.getresponse()
status = response.status
if status != 200:
    print 'ERROR'
    sys.exit(1)
reason = response.reason
answer = response.read()

in order to get the json just do:

received_json = None
try:
    json.loads(answer)
except:
    print 'ERROR'
    sys.exit(2)

Upvotes: 1

Evan Cordeiro
Evan Cordeiro

Reputation: 793

No JSON Object could be decoded and the response is on multiple lines are the keys here I think. That error is usually returned from mjson.tools on an empty string, whereas malformed JSON generally returns something more verbose.

The JSON parser will not look past the first newline (outside of a quote string value). It is probably receiving something like \r\n{"key":"value"} and failing. If the response is on multiple lines for some reason, then you should parse out the response body (JSON) without leading or trailing \r\n's

Upvotes: 2

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