How do I extract value of a JSON key using bash shell?

Question

I'm using bash shell. I would like to include something in my shell script that can extract the value of a certain key in a JSON string ...

davea$ json='{"id": "abc", "name": "dave"}'

I tried "grep", which failed

davea$ grep -Po '"id":.*?[^\\]",' $json
usage: grep [-abcDEFGHhIiJLlmnOoqRSsUVvwxZ] [-A num] [-B num] [-C[num]]
    [-e pattern] [-f file] [--binary-files=value] [--color=when]
    [--context[=num]] [--directories=action] [--label] [--line-buffered]
    [--null] [pattern] [file ...]

Then I found a solution involving Python, but this also failed ...

localhost:tmp davea$ echo $json | python -c 'import json,sys;obj=json.load(sys.stdin);print obj["id"]'
  File "<string>", line 1
    import json,sys;obj=json.load(sys.stdin);print obj["id"]

How can I extract the value for the "id" key without installing anything extra on my system?

Your python code works well for python2.x, and should work for python3 if you put brackets around the print argument. — pLumo
– pLumo, Commented Mar 5, 2020 at 15:45
@pLumo -- that was the issue, I had Python 3 installed but the code I was using was Python 2. — Dave
– Dave, Commented Mar 5, 2020 at 15:47
Your title says you want to use the bash shell, but your examples uses grep and python. Would it be ok to update the title? — Kusalananda
– Kusalananda ♦, Commented Mar 5, 2020 at 16:31

Kusalananda · Accepted Answer · 2020-03-05 16:26:15Z

4

Your python code works well. Be aware that you might need brackets around the argument to print if you use python3.

echo "$json" | python2 -c 'import json,sys;obj=json.load(sys.stdin);print obj["id"]'

echo "$json" | python3 -c 'import json,sys;obj=json.load(sys.stdin);print(obj["id"])'

Alternatively, use jq:

echo "$json" | jq -r .id

Output for all solutions above:

abc

edited Mar 5, 2020 at 16:26

Kusalananda♦

356k42 gold badges737 silver badges1.1k bronze badges

answered Mar 5, 2020 at 15:47

pLumo

23.2k2 gold badges43 silver badges70 bronze badges

Add a comment |

Stack Exchange Network

How do I extract value of a JSON key using bash shell?

1 Answer 1

You must log in to answer this question.

Hot Network Questions

How do I extract value of a JSON key using bash shell?

1 Answer 1

You must log in to answer this question.

Related

Hot Network Questions