yq/operators/encode-decode.md

Encoder / Decoder

Encode operators will take the piped in object structure and encode it as a string in the desired format. The decode operators do the opposite, they take a formatted string and decode it into the relevant object structure.

Note that you can optionally pass an indent value to the encode functions (see below).

These operators are useful to process yaml documents that have stringified embeded yaml/json/props in them.

Format	Decode (from string)	Encode (to string)
Yaml	from_yaml	to_yaml(i)/@yaml
JSON	from_json	to_json(i)/@json
Properties		to_props/@props
CSV		to_csv/@csv
TSV		to_tsv/@tsv

CSV and TSV format both accept either a single array or scalars (representing a single row), or an array of array of scalars (representing multiple rows).

Encode value as json string

Given a sample.yml file of:

a:
  cool: thing

then

yq eval '.b = (.a | to_json)' sample.yml

will output

a:
  cool: thing
b: |
  {
    "cool": "thing"
  }  

Encode value as json string, on one line

Pass in a 0 indent to print json on a single line.

Given a sample.yml file of:

a:
  cool: thing

then

yq eval '.b = (.a | to_json(0))' sample.yml

will output

a:
  cool: thing
b: '{"cool":"thing"}'

Encode value as json string, on one line shorthand

Pass in a 0 indent to print json on a single line.

Given a sample.yml file of:

a:
  cool: thing

then

yq eval '.b = (.a | @json)' sample.yml

will output

a:
  cool: thing
b: '{"cool":"thing"}'

Decode a json encoded string

Keep in mind JSON is a subset of YAML. If you want idiomatic yaml, pipe through the style operator to clear out the JSON styling.

Given a sample.yml file of:

a: '{"cool":"thing"}'

then

yq eval '.a | from_json | ... style=""' sample.yml

will output

cool: thing

Encode value as props string

Given a sample.yml file of:

a:
  cool: thing

then

yq eval '.b = (.a | @props)' sample.yml

will output

a:
  cool: thing
b: |
  cool = thing  

Encode value as yaml string

Indent defaults to 2

Given a sample.yml file of:

a:
  cool:
    bob: dylan

then

yq eval '.b = (.a | to_yaml)' sample.yml

will output

a:
  cool:
    bob: dylan
b: |
  cool:
    bob: dylan  

Encode value as yaml string, with custom indentation

You can specify the indentation level as the first parameter.

Given a sample.yml file of:

a:
  cool:
    bob: dylan

then

yq eval '.b = (.a | to_yaml(8))' sample.yml

will output

a:
  cool:
    bob: dylan
b: |
  cool:
          bob: dylan  

Decode a yaml encoded string

Given a sample.yml file of:

a: 'foo: bar'

then

yq eval '.b = (.a | from_yaml)' sample.yml

will output

a: 'foo: bar'
b:
  foo: bar

Update a multiline encoded yaml string

Given a sample.yml file of:

a: |
  foo: bar
  baz: dog  

then

yq eval '.a |= (from_yaml | .foo = "cat" | to_yaml)' sample.yml

will output

a: |
  foo: cat
  baz: dog  

Update a single line encoded yaml string

Given a sample.yml file of:

a: 'foo: bar'

then

yq eval '.a |= (from_yaml | .foo = "cat" | to_yaml)' sample.yml

will output

a: 'foo: cat'

Encode array of scalars as csv string

Scalars are strings, numbers and booleans.

Given a sample.yml file of:

- cat
- thing1,thing2
- true
- 3.40

then

yq eval '@csv' sample.yml

will output

cat,"thing1,thing2",true,3.40

Encode array of arrays as csv string

Given a sample.yml file of:

- - cat
  - thing1,thing2
  - true
  - 3.40
- - dog
  - thing3
  - false
  - 12

then

yq eval '@csv' sample.yml

will output

cat,"thing1,thing2",true,3.40
dog,thing3,false,12

Encode array of array scalars as tsv string

Scalars are strings, numbers and booleans.

Given a sample.yml file of:

- - cat
  - thing1,thing2
  - true
  - 3.40
- - dog
  - thing3
  - false
  - 12

then

yq eval '@tsv' sample.yml

will output

cat	thing1,thing2	true	3.40
dog	thing3	false	12