Calculates file offsets and other metadata for content stored in an
(optionally gzip compressed) tar archive. Once added, the tar archive
with metadata can be mounted as an Emscripten filesystem image, making the
contents of the archive available to the WebAssembly R process.
Details
The virtual filesystem metadata is appended to the end of the tar archive,
with the output replacing the original file. The resulting archive should be
hosted online so that its URL can be provided to webR for mounting on the
virtual filesystem.
If strip is greater than 0 the virtual filesystem metadata is generated
such that when mounted by webR the specified number of leading path elements
are removed. Useful for R package binaries where data files are stored in the
original .tgz file under a subdirectory. Files with fewer path name
elements than the specified amount are skipped.