Bash脚本使用jq遍历多行JSON对象

Question

I have to curl to a site (statuscake.com) that sends multiple items back in a JSON, each line of which contains multiple items. I want to extract from each line two of them, WebsiteName and TestID, so I can check if WebsiteName matches the one I'm interested in, get the TestID out and pass this to a second curl statement to delete the test.

Although it's more complex, the JSON that comes back is essentially of the form

[{"TestID": 123, "WebsiteName": "SomeSite1"}, {"TestID": 1234, "WebsiteName": "SomeSite2"}]

I can't seem to find a magic jq command to do it all in one - if there is one, I'd be really happy to see it.

I've got

cat $data | jq '[.[] | .WebsiteName]' 

to get an array of the website names (and a very similar one for the TestIDs, but I think I've done something daft. data is the information coming back from the curl to get the JSON and that's populated OK.

I want to be able to assign these to two arrays, names and ids, then search names for the index of the relevant name, grab the id from ids and pass that to the curl. Unless there's a better way.

Any advice please?

Answer 1

My Xidel can do it all at once by selecting the JSON with a XPath-like query:

Eg return all ids where the WebsiteName contains "site2" from an array of objects:

xidel /tmp/x.json -e '$json()[contains((.).WebsiteName, "site2")]/TestID'

Or eg to download the original JSON and then make the HTTP request with the ids:

xidel http://statuscake.com/your-url... -f '$json()[contains((.).WebsiteName, "site2")]/TestID!x"/your-delete-url{.}..."'

Answer 2

If I'm getting your question right, it sounds like what you want is to, for each element, select those where .WebsiteName == "needle" , and then get .TestID from it. You can do just that:

.[] | select(.WebsiteName == "needle") | .TestID

If you want an array as the result, you can wrap the above script in square brackets.

The jq filters startswith and endswith may be of interest to you. If you're going to pass the result back to cURL, you may also be interested in the @sh formatting filter and the -r command-line flag.

Answer 3

Assuming you have a bash 4+ and assuming the json is valid (does not contain newlines in strings, etc.) this works:

$ echo "$data"
[{"TestID": 123, "WebsiteName": "SomeSite1"}, {"TestID": 1234, "WebsiteName":
"SomeSite2"}, {"TestID": 555, "WebsiteName": "foo*ba@r blah[54]quux{4,5,6}"}]
$ declare -A arr
$ while IFS= read -r line; do
    eval "$line"
done < <(jq -M -r '.[] | @sh "arr[\(.WebsiteName)]+=\(.TestID)"' <<<"$data")
$ declare -p arr
declare -A arr='(["foo*ba@r blah[54]quux{4,5,6}"]="555" [SomeSite2]="1234" [SomeSite1]="123" )'

Answer 4

Here is a solution using only jq primitives.

  .[]
| if .WebsiteName == "SomeSite1" then .TestID else empty end

This is essentially the same as Santiago 's answer but if you are new to jq it may be informative because select/1 is defined as

 def select(f): if f then . else empty end;