grep command to find the value of key from json

Question

Please explain how to use grep command to extract some specified text from the following json -

{"result":"Customer information saved successfully with Customer id :59 and version :1","status":{"responseCode":200,"result":null,"responseMessage":"Success","responseType":"info"}}

After some googling, it looks like it is possible by using grep with a regular expression. But it is not working. Can you please point out the mistake

cat response.txt | grep -Po '(?<="Customer id ":)[0-9]+'

Assumption: response.txt contains the above json.

If yes please explain.

Hackaholic · Accepted Answer · 2014-12-27T18:29:30.617

6

you missed K:

cat response.txt | grep -Po 'Customer id :\K[0-9]+'
59

screenshot, its working: enter image description here

edited Dec 27 '14 at 18:29

answered Dec 27 '14 at 18:20

Hackaholic

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grep can read files on it's own, so `grep ... file` (useless use of cat). And the `\K` is a shorthand for what the OP use already, positive look-behind – Gilles Quénot Dec 27 '14 at 18:22
it is working....i had missed some text...Can u please explain it in details ..or can u give a link where can i find the detail documentation regarding it . – user1483747 Dec 27 '14 at 18:33
Can you explain what K does here? – shajin Apr 23 '18 at 11:53

score 0 · Answer 2 · answered Dec 27 '14 at 18:16

0

Try doing this :

$ jq -r '.result' json_file | grep -oP '(?<=Customer id :)\d+'
59

Check http://stedolan.github.io/jq/manual/

answered Dec 27 '14 at 18:16

Gilles Quénot

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I am aware of jq tool , but our server does not have jq tool installed . I have no other option than to use grep command . Is it possible ? – user1483747 Dec 27 '14 at 18:20
jq can be downloaded as user and executed directly without any dependencies – Gilles Quénot Dec 27 '14 at 18:20

grep command to find the value of key from json

2 Answers2