2.4 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.
Create yaml file
Running
yq eval --null-input '.a.b = "cat" | .x = "frog"'
will output
a:
b: cat
x: frog
Update node to be the child value
Given a sample.yml file of:
a: {b: {g: foof}}
'': null
then
yq eval '.a |= .b' sample.yml
will output
a: {g: foof}
'': null
Update node to be the sibling value
Given a sample.yml file of:
a: {b: child}
b: sibling
'': null
then
yq eval '.a = .b' sample.yml
will output
a: sibling
b: sibling
'': null
Updated multiple paths
Given a sample.yml file of:
a: fieldA
b: fieldB
c: fieldC
'': null
then
yq eval '(.a, .c) |= "potatoe"' sample.yml
will output
a: potatoe
b: fieldB
c: potatoe
'': null
Update string value
Given a sample.yml file of:
a: {b: apple}
'': null
then
yq eval '.a.b = "frog"' sample.yml
will output
a: {b: frog}
'': null
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}
'': null
then
yq eval '.a.b |= "frog"' sample.yml
will output
a: {b: frog}
'': null
Update selected results
Given a sample.yml file of:
a: {b: apple, c: cactus}
'': null
then
yq eval '(.a[] | select(. == "apple")) = "frog"' sample.yml
will output
a: {b: frog, c: cactus}
'': null
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:
{}
then
yq eval '.a.b |= "bogs"' sample.yml
will output
{a: {b: bogs}}
Update empty object and array
Given a sample.yml file of:
{}
then
yq eval '.a.b.[0] |= "bogs"' sample.yml
will output
{a: {b: [bogs]}}