Use the `alias` and `anchor` operators to read and write yaml aliases and anchors. The `explode` operator normalises a yaml file (dereference (or expands) aliases and remove anchor names). `yq` supports merge aliases (like `<<: *blah`) however this is no longer in the standard yaml spec (1.2) and so `yq` will automatically add the `!!merge` tag to these nodes as it is effectively a custom tag. ## Merge one map see https://yaml.org/type/merge.html Given a sample.yml file of: ```yaml - &CENTER x: 1 y: 2 - &LEFT x: 0 y: 2 - &BIG r: 10 - &SMALL r: 1 - !!merge <<: *CENTER r: 10 ``` then ```bash yq eval '.[4] | explode(.)' sample.yml ``` will output ```yaml x: 1 y: 2 r: 10 ``` ## Merge multiple maps see https://yaml.org/type/merge.html Given a sample.yml file of: ```yaml - &CENTER x: 1 y: 2 - &LEFT x: 0 y: 2 - &BIG r: 10 - &SMALL r: 1 - !!merge <<: - *CENTER - *BIG ``` then ```bash yq eval '.[4] | explode(.)' sample.yml ``` will output ```yaml r: 10 x: 1 y: 2 ``` ## Override see https://yaml.org/type/merge.html Given a sample.yml file of: ```yaml - &CENTER x: 1 y: 2 - &LEFT x: 0 y: 2 - &BIG r: 10 - &SMALL r: 1 - !!merge <<: - *BIG - *LEFT - *SMALL x: 1 ``` then ```bash yq eval '.[4] | explode(.)' sample.yml ``` will output ```yaml r: 10 x: 1 y: 2 ``` ## Get anchor Given a sample.yml file of: ```yaml a: &billyBob cat ``` then ```bash yq eval '.a | anchor' sample.yml ``` will output ```yaml billyBob ``` ## Set anchor Given a sample.yml file of: ```yaml a: cat ``` then ```bash yq eval '.a anchor = "foobar"' sample.yml ``` will output ```yaml a: &foobar cat ``` ## Set anchor relatively using assign-update Given a sample.yml file of: ```yaml a: b: cat ``` then ```bash yq eval '.a anchor |= .b' sample.yml ``` will output ```yaml a: &cat b: cat ``` ## Get alias Given a sample.yml file of: ```yaml b: &billyBob meow a: *billyBob ``` then ```bash yq eval '.a | alias' sample.yml ``` will output ```yaml billyBob ``` ## Set alias Given a sample.yml file of: ```yaml b: &meow purr a: cat ``` then ```bash yq eval '.a alias = "meow"' sample.yml ``` will output ```yaml b: &meow purr a: *meow ``` ## Set alias relatively using assign-update Given a sample.yml file of: ```yaml b: &meow purr a: f: meow ``` then ```bash yq eval '.a alias |= .f' sample.yml ``` will output ```yaml b: &meow purr a: *meow ``` ## Explode alias and anchor Given a sample.yml file of: ```yaml f: a: &a cat b: *a ``` then ```bash yq eval 'explode(.f)' sample.yml ``` will output ```yaml f: a: cat b: cat ``` ## Explode with no aliases or anchors Given a sample.yml file of: ```yaml a: mike ``` then ```bash yq eval 'explode(.a)' sample.yml ``` will output ```yaml a: mike ``` ## Explode with alias keys Given a sample.yml file of: ```yaml f: a: &a cat *a: b ``` then ```bash yq eval 'explode(.f)' sample.yml ``` will output ```yaml f: a: cat cat: b ``` ## Explode with merge anchors Given a sample.yml file of: ```yaml foo: &foo a: foo_a thing: foo_thing c: foo_c bar: &bar b: bar_b thing: bar_thing c: bar_c foobarList: b: foobarList_b !!merge <<: - *foo - *bar c: foobarList_c foobar: c: foobar_c !!merge <<: *foo thing: foobar_thing ``` then ```bash yq eval 'explode(.)' sample.yml ``` will output ```yaml foo: a: foo_a thing: foo_thing c: foo_c bar: b: bar_b thing: bar_thing c: bar_c foobarList: b: bar_b thing: foo_thing c: foobarList_c a: foo_a foobar: c: foo_c a: foo_a thing: foobar_thing ```