Myujth

Is it possible to use jq to turn the following JSON data

[
 
 "a": null,
 "b": [
 
 "c": "cc",
 "d": "dd1"
 ,
 
 "c": "cc",
 "d": "dd1",
 "e": "ee",
 "f": "ff"
 
 ]
 ,
 
 "b": [
 
 "c": "cc",
 "d": "dd2",
 "e": "ee",
 "f": "ff"
 
 ]
 
]

into

[
 
 "a": null,
 "b": [
 [
 "cc", "d1"
 ],
 [
 "cc", "d1", "ff"
 ]
 ]
 ,
 
 "b": [
 [
 "cc", "d2", "ff"
 ]
 ]
 
]

?

Note that the purpose is to reduce the b list with certain elements of its items based on a condition. The condition assigns the string d1 if the value of d is dd1, otherwise d2 is assigned if dd2 is present.

The following unsuccessful attempt demonstrates the idea:

$ jq -r '..b = [..b.c, ?, ..b.f?]'

This is probably not the best way to do what you want, but it does get the desired output and it has the conditional you asked about.

jq '..b |= map(
 [ .c,
 (if .d == "dd1" then "d1" elif .d == "dd2" then "d2" else . end),
 .f // empty
 ] )'

Without changing the value of the d key, you would use this jq filter:

jq '..b|=(to_entries|map(.value))' file

That updates the b array into all values of the inner objects.

If you want to update the d, you could use this filter:

jq '..b |= (to_entries|
 map(
 if(.key=="d") then 
 .value|=sub("d+";"d") 
 else . 
 end
 |.value)
 )' file

that adds a check if the key is d the associated value is updated to remove the duplicated d character from the string. This requires jq to support for regex (to be able to use the sub function).