multiple yaml docs to a json array

[coderplay]

I got a single yaml file with multple doc

a: 1
---
b: 2

How can I output a json like this

[
  {
    "a": 1
  },
  {
    "b": 2
  }
]

When I use yq e sample.yaml -j , it generates a invalid json

{
  "a": 1
}
{
  "b": 2
}

[mikefarah]

The command you've got up there creates a json doc for each yaml doc - which is why you are seeing that output.

What you'll need to do is:

yq ea '[.]' sample.yaml -j

• ea (or eval-all) to read all the documents at once (default is to read one doc at a time)
• [.] to put all the documents in an array

[coderplay]

@mikefarah Thanks for your quick reply. This command can't read the yaml from stdout

% cat /tmp/sample | yq ea -j
{
  "a": 1
}
{
  "b": 2
}

if I add '[.]'

 % cat /tmp/sample | yq ea '[.]' -j
Error: open [.]: no such file or directory

[mikefarah]

You just need to give it a - so it knows to read from STDIN:

cat file.yaml | yq e '.a.b[0].c' -