2.2 KiB
This operator is used to update node values. It can be used in either the:
plain form: =
Which will assign the LHS node values to the RHS node values. The RHS expression is run against the matching nodes in the pipeline.
relative form: |=
This will do a similar thing to the plain form, however, the RHS expression is run against the LHS nodes. This is useful for updating values based on old values, e.g. increment.
Examples
Update parent to be the child value
Given a sample.yml file of:
a:
b:
g: foof
then
yq eval '.a |= .b' sample.yml
will output
a:
g: foof
Update to be the sibling value
Given a sample.yml file of:
a:
b: child
b: sibling
then
yq eval '.a = .b' sample.yml
will output
a: sibling
b: sibling
Updated multiple paths
Given a sample.yml file of:
a: fieldA
b: fieldB
c: fieldC
then
yq eval '(.a, .c) |= "potatoe"' sample.yml
will output
a: potatoe
b: fieldB
c: potatoe
Update string value
Given a sample.yml file of:
a:
b: apple
then
yq eval '.a.b = "frog"' sample.yml
will output
a:
b: frog
Update string value via |=
Note there is no difference between = and |= when the RHS is a scalar
Given a sample.yml file of:
a:
b: apple
then
yq eval '.a.b |= "frog"' sample.yml
will output
a:
b: frog
Update selected results
Given a sample.yml file of:
a:
b: apple
c: cactus
then
yq eval '.a[] | select(. == "apple") |= "frog"' sample.yml
will output
a:
b: frog
c: cactus
Update array values
Given a sample.yml file of:
- candy
- apple
- sandy
then
yq eval '.[] | select(. == "*andy") |= "bogs"' sample.yml
will output
- bogs
- apple
- bogs
Update empty object
Given a sample.yml file of:
'': null
then
yq eval '.a.b |= "bogs"' sample.yml
will output
'': null
a:
b: bogs
Update empty object and array
Given a sample.yml file of:
'': null
then
yq eval '.a.b[0] |= "bogs"' sample.yml
will output
'': null
a:
b:
- bogs