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Read

yq r <yaml_file|json_file> <path>

This command can take a json file as input too, and will output yaml unless specified to export as json (-j)

Basic

Given a sample.yaml file of:

b:
  c: 2

then

yq r sample.yaml b.c

will output the value of '2'.

From Stdin

Given a sample.yaml file of:

cat sample.yaml | yq r - b.c

will output the value of '2'.

Splat

Given a sample.yaml file of:

---
bob:
  item1:
    cats: bananas
  item2:
    cats: apples

then

yq r sample.yaml bob.*.cats

will output

- bananas
- apples

Arrays

You can give an index to access a specific element: e.g.: given a sample file of

b:
  e:
    - name: fred
      value: 3
    - name: sam
      value: 4

then

yq r sample.yaml 'b.e[1].name'

will output 'sam'

Note that the path is in quotes to avoid the square brackets being interpreted by your shell.

Array Splat

e.g.: given a sample file of

b:
  e:
    - name: fred
      value: 3
    - name: sam
      value: 4

then

yq r sample.yaml 'b.e[*].name'

will output:

- fred
- sam

Note that the path is in quotes to avoid the square brackets being interpreted by your shell.

Keys with dots

When specifying a key that has a dot use key lookup indicator.

b:
  foo.bar: 7

yaml r sample.yaml 'b[foo.bar]'

yaml w sample.yaml 'b[foo.bar]' 9

Any valid yaml key can be specified as part of a key lookup.

Note that the path is in quotes to avoid the square brackets being interpreted by your shell.