yq/pkg/yqlib/doc/operators/encode-decode.md
2022-02-23 09:26:35 +11:00

6.4 KiB

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
XML from_xml to_xml(i)/@xml
Base64 @base64d @base64

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).

XML uses the --xml-attribute-prefix and xml-content-name flags to identify attributes and content fields.

Base64 assumes rfc4648 encoding. Encoding and decoding both assume that the content is a string.

{% hint style="warning" %} Note that versions prior to 4.18 require the 'eval/e' command to be specified.

yq e <exp> <file> {% endhint %}

Encode value as json string

Given a sample.yml file of:

a:
  cool: thing

then

yq '.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 '.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 '.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 '.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 '.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 '.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 '.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 '.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 '.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 '.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 '@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 '@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 '@tsv' sample.yml

will output

cat	thing1,thing2	true	3.40
dog	thing3	false	12

Encode value as xml string

Given a sample.yml file of:

a:
  cool:
    foo: bar
    +id: hi

then

yq '.a | to_xml' sample.yml

will output

<cool id="hi">
  <foo>bar</foo>
</cool>

Encode value as xml string on a single line

Given a sample.yml file of:

a:
  cool:
    foo: bar
    +id: hi

then

yq '.a | @xml' sample.yml

will output

<cool id="hi"><foo>bar</foo></cool>

Encode value as xml string with custom indentation

Given a sample.yml file of:

a:
  cool:
    foo: bar
    +id: hi

then

yq '{"cat": .a | to_xml(1)}' sample.yml

will output

cat: |
  <cool id="hi">
   <foo>bar</foo>
  </cool>  

Decode a xml encoded string

Given a sample.yml file of:

a: <foo>bar</foo>

then

yq '.b = (.a | from_xml)' sample.yml

will output

a: <foo>bar</foo>
b:
  foo: bar

Encode a string to base64

Given a sample.yml file of:

coolData: a special string

then

yq '.coolData | @base64' sample.yml

will output

YSBzcGVjaWFsIHN0cmluZw==

Encode a yaml document to base64

Pipe through @yaml first to convert to a string, then use @base64 to encode it.

Given a sample.yml file of:

a: apple

then

yq '@yaml | @base64' sample.yml

will output

YTogYXBwbGUK

Decode a base64 encoded string

Decoded data is assumed to be a string.

Given a sample.yml file of:

coolData: V29ya3Mgd2l0aCBVVEYtMTYg8J+Yig==

then

yq '.coolData | @base64d' sample.yml

will output

Works with UTF-16 😊

Decode a base64 encoded yaml document

Pipe through from_yaml to parse the decoded base64 string as a yaml document.

Given a sample.yml file of:

coolData: YTogYXBwbGUK

then

yq '.coolData |= (@base64d | from_yaml)' sample.yml

will output

coolData:
  a: apple