Let's say I have the below json object:
{
"d": {
"e": {
"bar": 2
}
},
"a": {
"b": {
"c": {
"foo": 1
}
}
}
}
I want to get the value foo without typing '.a.b.c.foo'
I realize I can do...
echo '{ "a":{"b":{"c":{ "foo":1}}},"d":{"e":{"bar":2}}}' | jq '.[][][].foo' but is there a recursive wild in jq? like **? I know for sure jq doesn't support *, is there a way to have jq support jsonpath?
Or maybe even just another cli tool that does support json path?
In jq 1.4 you could do this:
$ jq '..|.foo?' file.json
If you're stuck with 1.3 you could use
$ jq 'recurse(if type == "array" or type == "object" then .[] else empty end) | if type == "object" then . else empty end | .foo' file.json
which is a bit of a mouthful... That's why 1.4 has .., which recurses down through all iterables in ., and the ? operator, which doesn't bother indexing that which can't be.
Related
My question is similar to Unix jq parsing wildcards but want to merge to the original JSON.
Say, input JSON:
{
"a": {
"1": {
"c": "text1"
},
"999": {
"c": "text99"
}
}
}
I want to manipulate the inner "c": "text1" and modify it to "c": "newtext". But, also need to merge with the original JSON. IOW, it is not about extracting, but about manipulating.
Expected output:
{
"a": {
"1": {
"c": "newtext"
},
"999": {
"c": "text99"
}
}
}
I tried:
.. | .c? |= (sub("^text1$";"newtext"))
But, it throws null (null) cannot be matched, as it is not a string
jqplay: https://jqplay.org/s/2nFAus6Umz
Just walk the path with the expression to select an object type when .c equals to your desired value
jq 'walk(if type == "object" and .c == "text1" then .c |= "newtext" else . end)'
jqplay demo
Along the lines of your attempt:
(.. | objects | select(has("c")) | .c) |= (sub("^text1$";"newtext"))
or in order of increasing brevity:
(.. | select(try has("c")) | .c) |= (sub("^text1$";"newtext"))
(.. | select(has("c")?) | .c) |= (sub("^text1$";"newtext"))
I'm trying to extract the value of an JSON object using jq --stream, because the real data can the size of multiple GigaBytes.
This is the JSON I'm using for my tests, where I want to extract the value of item:
{
"other": "content here",
"item": {
"A": {
"B": "C"
}
},
"test": "test"
}
The jq options I'm using:
jq --stream --null-input 'fromstream(inputs | select(.[0][0] == "item"))[]' example.json
However, I don't get any output with this command.
A strange thing I found is that when removing the object after the item the above command seems to work:
{
"other": "content here",
"item": {
"A": {
"B": "C"
}
}
}
The result looks as expected:
❯ jq --stream --null-input 'fromstream(inputs | select(.[0][0] == "item"))[]' example.json
{
"A": {
"B": "C"
}
}
But as I cannot control the input JSON this is not the solution.
I'm using jq version 1.6 on MacOS.
You didn't truncate the stream, therefore after filtering it to only include the parts below .item, fromstream is missing the final back-tracking item [["item"]]. Either add it manually at the end (not recommended, this would also include the top-level object in the result), or, much simpler, use 1 | truncate_stream to strip the first level altogether:
jq --stream --null-input '
fromstream(1 | truncate_stream(inputs | select(.[0][0] == "item")))
' example.json
{
"A": {
"B": "C"
}
}
Alternatively, you can use reduce and setpath to build up the result object yourself:
jq --stream --null-input '
reduce inputs as $in (null;
if $in | .[0][0] == "item" and has(1) then setpath($in[0];$in[1]) else . end
)
' example.json
{
"item": {
"A": {
"B": "C"
}
}
}
To remove the top level object, either filter for .item at the end, or, similarly to truncate_stream, remove the path's first item using [1:] to strip the first level:
jq --stream --null-input '
reduce inputs as $in (null;
if $in | .[0][0] == "item" and has(1) then setpath($in[0][1:];$in[1]) else . end
)
' example.json
{
"A": {
"B": "C"
}
}
i try to remove some entries from a dict in a json. It works by using == but with contains it doesn't work.
Jq call working:
jq 'del(.entries[] | select(.var == "foo"))' input.json
Jq call not working:
jq 'del(.entries[] | select(.var | contains("foo")))' input.json
input.json:
{
"entries": [
{
"name": "test1",
"var": "foo"
},
{
"name": "test2",
"var": "bar"
}
]
}
Output:
{
"entries": [
{
"name": "test2",
"var": "bar"
}
]
}
The result of jq '.entries[] | select(.var == "foo")' input.json and jq '.entries[] | select(.var | contains("foo"))' input.json is the same, so I think the two del-calls should also work.
Is this a bug in jq or did I something wrong?
This must be a bug as it seems to work perfectly on jq 1.6 (try it here).
If you're unable to update to jq 1.6 you should be able to use the following command instead, which I've successfully tested on jq 1.5 :
jq '.entries |= map(select(.var | contains("foo") | not))' file.json
Using Bash and jq, if I have a Bash variable filter F of the form .<key1>.<key2>...<keyN> and I want to slice a Bash variable JSON object O so that the result is just that slice of the object including all keys in F, how can this be done with jq?
For example, suppose:
O='
{
"a":
{
"b":
{
"c": { "p":1 },
"x": 1
},
"x": 2
},
"x": 3
}'
Then, doing:
F='.a.b.c'; jq -r "$F" <<<"$O"
results in:
{
"p": 1
}
But, I want the slice to include parent key hierarchy.
Inelegant Solution
I have come up with a solution, but it involves 2 calls to jq:
F='.a.b.c'; S="$(jq -r "$F" <<<"$O"); jq --null-input -r "$F |= $S"
that results in:
{
"a": {
"b": {
"c": {
"p": 1
}
}
}
}
The solution must work for any valid O and F Bash variable where O stores a JSON object and F is a simple filter of key names only as described above. For example:
F='.a.b'; S="$(jq -r "$F" <<<"$O")"; jq --null-input -r "$F |= $S"
results in:
{
"a": {
"b": {
"c": {
"p": 1
},
"x": 1
}
}
}
Can slicing an object with a key-hierarchy filter be done more simply in jq?
Provided $F is a valid jq path expression (i.e., so that jq -n "$F" works):
jq "$F as \$v | null | $F |= \$v" <<< "$O"
(I included the |= from your solution to show the similarity, but here you could drop the |.)
I have the given JSON and want to change the id value of all elements, which starts with test in the name element:
{
"other-value": "some-id",
"values": [
{
"name": "test-2017-12-01",
"id": "1"
},
{
"name": "othert",
"id": "2"
}
]
}
The following jq commands works jqplay
jq (.values[] | select(.name == "test-afs").id) |= "NEWID"
But when I try it with startswith it stops working, what am I missing? jqplay
(.values[] | select(.name | startswith("test")).id) |= "NEWID"
jq: error (at :14): Invalid path expression near attempt to access element "id" of {"name":"test-afs","id":"id"}
exit status 5
You can also use map, like this:
jq '(.values)|=(map((if .name|startswith("test") then .id="NEWID" else . end)))' file
Output:
{
"other-value": "some-id",
"values": [
{
"name": "test-2017-12-01",
"id": "NEWID"
},
{
"name": "othert",
"id": "2"
}
]
}
Please note that since the release of jq 1.5, jq has been enhanced to support the query that previously failed. For example, using the current 'master' version:
jq -c '(.values[] | select(.name | startswith("test")).id) |= "NEWID"'
{"other-value":"some-id","values":[{"name":"test-2017-12-01","id":"NEWID"},{"name":"othert","id":"2"}]}
Using earlier versions of jq, if/then/else/end can be used in this type of situation as follows:
.values[] |= if .name | startswith("test") then .id = "NEWID" else . end
If using map, a minimalist expression would be:
.values |= map(if .name|startswith("test") then .id = "NEWID" else . end)