Comment Operators
Use these comment operators to set or retrieve comments. Note that line comments on maps/arrays are actually set on the key node as opposed to the value (map/array). See below for examples.
Like the = and |= assign operators, the same syntax applies when updating comments:
plain form: =
=This will set the LHS nodes' comments equal to the expression on the RHS. The RHS is run against the matching nodes in the pipeline
relative form: |=
|=This is similar to the plain form, but it evaluates the RHS with each matching LHS node as context. This is useful if you want to set the comments as a relative expression of the node, for instance its value or path.
Set line comment
Set the comment on the key node for more reliability (see below).
Given a sample.yml file of:
a: catthen
yq '.a line_comment="single"' sample.ymlwill output
a: cat # singleSet line comment of a maps/arrays
For maps and arrays, you need to set the line comment on the key node. This will also work for scalars.
Given a sample.yml file of:
then
will output
Use update assign to perform relative updates
Given a sample.yml file of:
then
will output
Where is the comment - map key example
The underlying yaml parser can assign comments in a document to surprising nodes. Use an expression like this to find where you comment is. 'p' indicates the path, 'isKey' is if the node is a map key (as opposed to a map value). From this, you can see the 'hello-world-comment' is actually on the 'hello' key
Given a sample.yml file of:
then
will output
Retrieve comment - map key example
From the previous example, we know that the comment is on the 'hello' key as a lineComment
Given a sample.yml file of:
then
will output
Where is the comment - array example
The underlying yaml parser can assign comments in a document to surprising nodes. Use an expression like this to find where you comment is. 'p' indicates the path, 'isKey' is if the node is a map key (as opposed to a map value). From this, you can see the 'under-name-comment' is actually on the first child
Given a sample.yml file of:
then
will output
Retrieve comment - array example
From the previous example, we know that the comment is on the first child as a headComment
Given a sample.yml file of:
then
will output
Set head comment
Given a sample.yml file of:
then
will output
Set head comment of a map entry
Given a sample.yml file of:
then
will output
Set foot comment, using an expression
Given a sample.yml file of:
then
will output
Remove comment
Given a sample.yml file of:
then
will output
Remove (strip) all comments
Note the use of ... to ensure key nodes are included.
Given a sample.yml file of:
then
will output
Get line comment
Given a sample.yml file of:
then
will output
Get head comment
Given a sample.yml file of:
then
will output
Head comment with document split
Given a sample.yml file of:
then
will output
Get foot comment
Given a sample.yml file of:
then
will output
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