get_file: Downloads a file from a URL if it not already in the cache.
In dfalbel/keras: R Interface to 'Keras'

Passing the MD5 hash will verify the file after download as well as if it is already present in the cache.

get_file(
  fname,
  origin,
  file_hash = NULL,
  cache_subdir = "datasets",
  hash_algorithm = "auto",
  extract = FALSE,
  archive_format = "auto",
  cache_dir = NULL
)

`fname`	Name of the file. If an absolute path `/path/to/file.txt` is specified the file will be saved at that location.
`origin`	Original URL of the file.
`file_hash`	The expected hash string of the file after download. The sha256 and md5 hash algorithms are both supported.
`cache_subdir`	Subdirectory under the Keras cache dir where the file is saved. If an absolute path `/path/to/folder` is specified the file will be saved at that location.
`hash_algorithm`	Select the hash algorithm to verify the file. options are 'md5', 'sha256', and 'auto'. The default 'auto' detects the hash algorithm in use.
`extract`	True tries extracting the file as an Archive, like tar or zip.
`archive_format`	Archive format to try for extracting the file. Options are 'auto', 'tar', 'zip', and None. 'tar' includes tar, tar.gz, and tar.bz files. The default 'auto' is ('tar', 'zip'). None or an empty list will return no matches found.
`cache_dir`	Location to store cached files, when `NULL` it defaults to the Keras configuration directory.