Like the multiple operator in `jq`, depending on the operands, this multiply operator will do different things. Currently only objects are supported, which have the effect of merging the RHS into the LHS. Upcoming versions of `yq` will add support for other types of multiplication (numbers, strings). Note that when merging objects, this operator returns the merged object (not the parent). This will be clearer in the examples below. ## Merging files Note the use of eval-all to ensure all documents are loaded into memory. ```bash yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' file1.yaml file2.yaml ``` ## Merge objects together, returning merged result only Given a sample.yml file of: ```yaml a: field: me fieldA: cat b: field: g: wizz fieldB: dog ``` then ```bash yq eval '.a * .b' sample.yml ``` will output ```yaml field: g: wizz fieldA: cat fieldB: dog ``` ## Merge objects together, returning parent object Given a sample.yml file of: ```yaml a: field: me fieldA: cat b: field: g: wizz fieldB: dog ``` then ```bash yq eval '. * {"a":.b}' sample.yml ``` will output ```yaml a: field: g: wizz fieldA: cat fieldB: dog b: field: g: wizz fieldB: dog ``` ## Merge keeps style of LHS Given a sample.yml file of: ```yaml a: {things: great} b: also: "me" ``` then ```bash yq eval '. * {"a":.b}' sample.yml ``` will output ```yaml a: {things: great, also: "me"} b: also: "me" ``` ## Merge arrays Given a sample.yml file of: ```yaml a: - 1 - 2 - 3 b: - 3 - 4 - 5 ``` then ```bash yq eval '. * {"a":.b}' sample.yml ``` will output ```yaml a: - 3 - 4 - 5 b: - 3 - 4 - 5 ``` ## Merge to prefix an element Given a sample.yml file of: ```yaml a: cat b: dog ``` then ```bash yq eval '. * {"a": {"c": .a}}' sample.yml ``` will output ```yaml a: c: cat b: dog ``` ## Merge with simple aliases Given a sample.yml file of: ```yaml a: &cat c: frog b: f: *cat c: g: thongs ``` then ```bash yq eval '.c * .b' sample.yml ``` will output ```yaml g: thongs f: *cat ``` ## Merge does not copy anchor names Given a sample.yml file of: ```yaml a: c: &cat frog b: f: *cat c: g: thongs ``` then ```bash yq eval '.c * .a' sample.yml ``` will output ```yaml g: thongs c: frog ``` ## Merge 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 '.foobar * .foobarList' sample.yml ``` will output ```yaml c: foobarList_c <<: - *foo - *bar thing: foobar_thing b: foobarList_b ```