$ cue help flags
Non-CUE files are merged at their roots by default.
The can be combined differently or treated as different files
by using a combination of the following flags.


Individual files

To treat non-cue files as individual files, use --no-merge flag.
This is the default for vet. This flag only applies to data files
when used in combination with the --schema/-d flag.


Assigning values to a CUE path

The --path/-l flag can be used to specify a CUE path at which to
place a value. Each -l flag specifies either a CUE expression or
a CUE field (without the value following the colon), both of
which are evaluated within the value. Together, the -l flags
specify the path at increasingly deeper nesting. An expression
may refer to builtin packages as long as the name can be uniquely
identified.

The --with-context flag can be used to evaluate the label
expression within a struct of contextual data, instead of
within the value itself. This struct has the following fields:

{
	// data holds the original source data
	// (perhaps one of several records in a file).
	data: _
	// filename holds the full path to the file.
	filename: string
	// index holds the 0-based index element of the
	// record within the file. For files containing only
	// one record, this will be 0.
	index: uint & <recordCount
	// recordCount holds the total number of records
	// within the file.
	recordCount: int & >=1
}


Handling multiple documents or streams

To handle multi-document files, such as JSON Lines or YAML
files with document separators (---), the user must specify
the --path, --list, or --files flag.
The --path flag merges each element into a single package as
if each element was defined in a separate file. The --list flag
concatenates each entry in a file into a list.
Using --list flag in combination with the --path flag
concatenates entries with the same path into a list, instead of
unifying them.
Finally, the --files option causes each entry to be written to
a different file. The -files flag may only be used in
combination with the import command.


Choosing the language version

The --language-version flag selects a fallback language version
for CUE that belongs to no module, such as files outside any
module, standard input, and the --expression and --schema flags,
and the target version of CUE that commands generate from it. It
accepts a canonical semantic version, such as v0.17.0.

The flag is only a fallback. The files of a module that declares a
language version keep that version, and a file's @version attribute
takes precedence. It is not an error if the flag applies to no
input, so the same command can be repeated while files move into
modules or gain @version attributes.

A file outside any module may declare its own version with a
@version(v0.17.0) file attribute. It must be the file's first
attribute, before the package clause and any @experiment attribute.
In a file of a module that declares a language version, it is an
error.


Examples:

# Put a value at a path based on its "kind" and "name" fields.
$ cue eval -l 'strings.ToLower(kind)' -l name foo.yaml

# Include a schema under the "myschema" field using the path notation.
$ cue eval -l myschema: schema: foo.json

# Base the path values on its kind and file name.
$ cue eval --with-context -l 'path.Base(filename)' -l data.kind foo.yaml

# Evaluate a file outside any module as written for v0.17.0.
$ cue eval --language-version v0.17.0 report.cue