My input file looks something like this:
{
"login": "dmaxfield",
"id": 7449977,
...
}
{
"login": "dmaxfield",
"id": 7449977,
...
}
I can get all the login names with this : cat members | jq '.[].login'
but I have not been able to crack the syntax to get both the login and id?
You can use jq '.[] | .login, .id' to obtain each login followed by its id.
This works for me:
> echo '{"a":1,"b":2,"c":3}{"a":1,"b":2,"c":3}' | jq '{a,b}'
{
"a": 1,
"b": 2
}
{
"a": 1,
"b": 2
}
Just provide one more example here (jq-1.6):
Walk through an array and select a field of an object element and a field of object in that object
echo '[{"id":1, "private_info": {"name": "Ivy", "age": 18}}, {"id":2, "private_info": {"name": "Tommy", "aga": 18}}]' | jq ".[] | {id: .id, name: .private_info.name}" -
{
"id": 1,
"name": "Ivy"
}
{
"id": 2,
"name": "Tommy"
}
Without the example data:
jq ".[] | {id, name: .private_info.name}" -
.[]: walk through an array
{id, name: .private_info.name}: take .id and .private_info.name and wrap it into an object with field name "id" and "name" respectively
In order to select values which are indented to different levels (i.e. both first and second level), you might use the following:
echo '[{"a":{"aa":1,"ab":2},"b":3,"c":4},{"a":{"aa":5,"ab":6},"b":7,"c":8}]' \
| jq '.[]|[.a.aa,.a.ab,.b]'
[
1,
2,
3
]
[
5,
6,
7
]
Related
In this example I only want isGreaterThanOne field to be shown if it's true. Here's what I started with (always shown)
echo '[{"a":5},{"a":1}]' | jq '[.[] | {value:.a, isGreaterThanOne:(.a>1)}]'
I inserted an if statement
echo '[{"a":5},{"a":1}]' | jq '[.[] | {value:.a, X:(if .a>1 then "Y" else "N" end) }]'
Then got stuck trying to move the field into the conditional. Also it seems like I must have an else with an if
echo '[{"a":5},{"a":1}]' | jq '[.[] | {value:.a, (if .a>1 then (K:"Y)" else (L:"N") end) }]'
I want the below as the result (doesn't need to be pretty printed)
[
{
"value": 5,
"X": "Y"
},
{
"value": 1,
}
]
Using if, make one branch provide an empty object {} which wouldn't contain the extra field:
map({value: .a} + if .a > 1 then {X: "Y"} else {} end)
Demo
Alternatively, equip only selected items with the extra field:
map({value: .a} | select(.value > 1).X = "Y")
Demo
Output:
[
{
"value": 5,
"X": "Y"
},
{
"value": 1
}
]
input json:
[
{
"user": "u1"
},
{
"user": "u2",
"groups": [
{
"id": "100001",
"name": "G1"
},
{
"id": "100002",
"name": "G2"
}
]
},
{
"user": "u3",
"groups": [
{
"id": "100001",
"name": "G1"
}
]
}
]
I want to find all users belonging to specific group (searching by group name or group id in the groups array)
$ jq -r '.[]|select(.groups[].name=="G1" | .user)' json
jq: error (at json:27): Cannot iterate over null (null)
Desired output format when searching of example group G1 would be:
u2
u3
Additional question:
Is it possible to produce comma-separated output u2,u3 without using external utilities like tr?
Better enter your serach data from parameters using --arg and use any to avoid duplicate outputs if both inputs match:
jq -r --arg id "" --arg name "G1" '
.[] | select(.groups | map(.id == $id or .name == $name) | any)? | .user
'
u2
u3
Demo
Using ? as the Optional Object Identifier-Index operator, you could do a select as below
map(select(.groups[].name == "G1")? | .user)
and un-wrap the results from the array by using [] at the end of the filter. To combine multiple selection conditions use the boolean operators with and/or inside the select statement
See demo on jqplay
Assuming the below input, how can I detect the presence of duplicates in the replicas list? (replicas":[5,5,6]")
{"version":1,
"partitions":
[{"topic":"mytopic1","partition":3,"replicas":[4,5],"log_dirs":["any","any"]},
{"topic":"mytopic1","partition":1,"replicas":[5,5,6],"log_dirs":["any","any"]},
{"topic":"mytopic2","partition":2,"replicas":[6,5],"log_dirs":["any","any"]}]
}
This one will give you an array of just the partitions with duplicates in the replicas field:
jq '[.partitions[] | select((.replicas | length) != (.replicas | unique | length))]' input.json
Pretty-printed example output:
[
{
"topic": "mytopic1",
"partition": 1,
"replicas": [
5,
5,
6
],
"log_dirs": [
"any",
"any"
]
}
]
So I have big json, where I need to take some subtree and copy it to other place, but with some properties updated (a lot of them). So for example:
{
"items": [
{ "id": 1, "other": "abc"},
{ "id": 2, "other": "def"},
{ "id": 3, "other": "ghi"}
]
}
and say, that i'd like to duplicate record having id == 2, and replace char e in other field with char x using regex. That could go (I'm sure there is a better way, but I'm beginner) something like:
jq '.items |= . + [.[]|select (.id == 2) as $orig | .id=4 | .other=($orig.other | sub("e";"x"))]'<sample.json
producing
{
"items": [
{
"id": 1,
"other": "abc"
},
{
"id": 2,
"other": "def"
},
{
"id": 3,
"other": "ghi"
},
{
"id": 4,
"other": "dxf"
}
]
}
Now that's great. But suppose, that there ins't just one other field. There are multitude of them, and over deep tree. Well I can issue multiple sub operations, but assuming, that replacement pattern is sufficiently selective, maybe we can turn the whole JSON subtree to string (trivial, tostring method) and replace all occurences using singe sub call. But how to turn that substituted string back to — is it call object? — to be able to add it back to items array?
Here's a program that might be a solution to the general problem you are describing, but if not at least illustrates how problems of this type can be solved. Note in particular that there is no explicit reference to a field named "other", and that (thanks to walk) the update function is applied to all candidate JSON objects in the input.
def update($n):
if .items | length > 0
then ((.items[0]|keys_unsorted) - ["id"]) as $keys
| if ($keys | length) == 1
then $keys[0] as $key
| (.items|map(.id) | max + 1) as $newid
| .items |= . + [.[] | select(.id == $n) as $orig | .id=$newid | .[$key]=($orig[$key] | sub("e";"x"))]
else .
end
else .
end;
walk(if type == "object" and has("items") then update(2) else . end)
I am trying to use jq to solve this problem.
Suppose I have the following object
{
"listA": [
{
"id": "12345",
"code": "001"
}
]
"listB": [
{
"id": "12345",
"prop": "AABBCC"
}
]
}
In reality my two lists are longer, but the id isn't repeated within each list.
How may I combine the two lists into a single list where each item is an object with the non-id properties for the given id are collected into a single object?
For example, from the object above, I'd like the following:
{
"listC" : [
{
"id": "12345",
"code": "001",
"prop": "AABBCC"
}
]
}
A simple way would be to concatenate the arrays, group the elements by id and map each group into a single object using add;
jq '.listA+.listB | group_by(.id) | map(add)' test.json
If there may be more than two arrays you need to merge in the file, you could instead use flatten to concatenate all of them.
Test case below
# cat test.json
{
"listA": [
{ "id": "12345", "code": "001" },
{ "id": "12346", "code": "002" }
],
"listB": [
{ "id": "12345", "prop": "AABBCC" }
]
}
# jq 'flatten | group_by(.id) | map(add)' test.json
# or
# jq '.listA+.listB | group_by(.id) | map(add)' test.json
[
{
"id": "12345",
"code": "001",
"prop": "AABBCC"
},
{
"id": "12346",
"code": "002"
}
]
Using group_by entails a sort, which is unnecessary, so if efficiency is a concern, then an alternative approach such as the following should be considered:
INDEX(.listA[]; .id) as $one
| INDEX(.listB[]; .id) as $two
| reduce ($one|keys_unsorted[]) as $k ($two; .[$k] += $one[$k])
| {listC: [.[]] }