If a SHA-1 hash is specified with the sha1 argument, then this function will check the SHA-1 hash of the downloaded file to make sure it matches the expected value, and throw an error if it does not match. If the SHA-1 hash is not specified, it will print a message displaying the hash of the downloaded file. The purpose of this is to improve security when running remotely-hosted code; if you have a hash of the file, you can be sure that it has not changed. For convenience, it is possible to use a truncated SHA1 hash, down to 6 characters, but keep in mind that a truncated hash won't be as secure as the full hash.

source_url(url, ..., sha1 = NULL)





other options passed to source()


The (prefix of the) SHA-1 hash of the file at the remote URL.

See also


if (FALSE) { source_url("https://gist.github.com/hadley/6872663/raw/hi.r") # With a hash, to make sure the remote file hasn't changed source_url("https://gist.github.com/hadley/6872663/raw/hi.r", sha1 = "54f1db27e60bb7e0486d785604909b49e8fef9f9") # With a truncated hash source_url("https://gist.github.com/hadley/6872663/raw/hi.r", sha1 = "54f1db27e60") }