Path Methods

CXL provides 5 built-in methods for extracting components from file path strings. All path methods take a string receiver and return a string. They return null when the receiver is null or when the requested component does not exist.

file_name() -> String

Returns the full filename (with extension) from the path.

$ cxl eval -e 'emit result = "/data/reports/sales.csv".file_name()'

{
  "result": "sales.csv"
}

file_stem() -> String

Returns the filename without the extension.

$ cxl eval -e 'emit result = "/data/reports/sales.csv".file_stem()'

{
  "result": "sales"
}

extension() -> String

Returns the file extension (without the leading dot).

$ cxl eval -e 'emit result = "/data/reports/sales.csv".extension()'

{
  "result": "csv"
}

Returns null when no extension is present:

$ cxl eval -e 'emit result = "/data/reports/README".extension()'

{
  "result": null
}

parent() -> String

Returns the parent directory path.

$ cxl eval -e 'emit result = "/data/reports/sales.csv".parent()'

{
  "result": "/data/reports"
}

parent_name() -> String

Returns just the name of the parent directory (not the full path).

$ cxl eval -e 'emit result = "/data/reports/sales.csv".parent_name()'

{
  "result": "reports"
}

Practical examples

Organize output by source directory:

emit source_dir = $pipeline.source_file.parent_name()
emit source_type = $pipeline.source_file.extension()

Extract file identifiers:

emit file_id = $pipeline.source_file.file_stem()
emit is_csv = $pipeline.source_file.extension() == "csv"

Route by file type:

let ext = input_path.extension()
emit format = match ext {
  "csv"  => "delimited",
  "json" => "structured",
  "xml"  => "markup",
  _      => "unknown"
}