This Commented CUE demonstrates how to use the cue command to combine multiple YAML files by making reference to the files’ metadata.

The TERMINAL section shows the use of:

• the --with-context parameter, which makes information about each input file available as metadata
• the filename metadata field combined with the -l parameter, which places each file’s contents at an individual and deterministic location in the evaluation space

a: 1
b: 2
c: 3

a: a string
b: true
c: 42

- a list element
- another element
- the last element

package example

// inputs is the location under which we place
// each data file's contents, so that their
// contents can be accessed by the CUE in this
// file. The cue CLI -l parameter places them
// here, under a secondary key determined by each
// file's name.
inputs: [string]: _

output: {
	for _name, _content in inputs {
		(_name): {
			filename: _name
			content:  _content
		}
	}
}

$ cue export --with-context -l 'inputs:' -l 'path.Base(filename)' -e output a.yaml b.yml c.yaml example.cue --out yaml
a.yaml:
  filename: a.yaml
  content:
    a: 1
    b: 2
    c: 3
b.yml:
  filename: b.yml
  content:
    a: a string
    b: true
    c: 42
c.yaml:
  filename: c.yaml
  content:
    - a list element
    - another element
    - the last element

Related content

• How-to Guide: Combining multiple JSON files by using file metadata
• Reference: cue flags documents the --with-context and -l flags