describe #

Print a human-readable description of a VI: its signature, inputs and outputs, constants, control flow, and the operations on its block diagram — without opening LabVIEW. describe never requires primitive or vi.lib mappings, so it works on any VI out of the box.

Synopsis #

lvkit describe <input_path> [options]

Arguments #

Options #

Example #

lvkit describe "Convert File Extension (String).vi" --search-path libraries/extracted

# Convert File Extension (String)__ogtk.vi
 
  convert_file_extension_(string)__ogtk(file name: str, new ending (none): str) -> new filename: str, prev ending: str
 
## Inputs
  file name: str (unknown)
  new ending (none): str (unknown)
 
## Outputs
  new filename: str
  prev ending: str
 
## Constants
  (unnamed): str = '\\.[~\\.]*$'
 
## Control Flow
  Case structure (2 frames, gated on new ending (none))
 
## Operations
Match Pattern [prim 1535]
Case Structure (2 frames)
  Frame "Default" (default):
    Match Pattern [prim 1535]
    Less Than 0? [prim 1118]
    Select [prim 1516]
    Format String
    (unnamed): str = '^\\.'
    (unnamed): str = '.%s'
    (unnamed): str = '%s'
  Frame "":
    (pass-through)

Notes #

• The generated Python-style signature (convert_file_extension_(string)__ogtk(...)) is a preview of the name and parameters generate would use — it does not require code generation to succeed.
• The (unknown) after an input (e.g. file name: str (unknown)) is the terminal's connection requirement, not its type — the type is the str before it. The connector-pane rule prints as required, recommended, or optional; unknown means the VI doesn't record one for that terminal.
• [prim N] after an operation (e.g. Match Pattern [prim 1535]) is the primitive's primResID, LabVIEW's internal ID for that built-in node.
• An unresolved SubVI is not an error. If a call's target isn't found on --search-path, describe still lists it under ## Dependencies — just without a signature or description, since those come from the target VI.

Errors #

If input_path doesn't exist, describe prints Error: Path not found and exits non-zero. If input_path isn't a .vi (a .lvlib, .lvclass, or directory), it prints Error: Expected .vi or *_BDHb.xml file: <path> and exits non-zero — use structure for those instead.

See also #

• generate — the Python code this VI's signature previews, once you're ready to convert it.
• render — a faithful, interactive block-diagram SVG instead of text.
• structure — for .lvlib/.lvclass members rather than a single VI.