Validate a file path argument

saveRDS() and writeLines() take a connection as well as a path, so a value that is neither gets as far as the file system before anything complains. On the reading side readRDS() on a path that does not exist raises "cannot open the connection", and the file it could not open is named only in the accompanying warning.

Usage

check_path(path, arg = "path", must_exist = FALSE)

Arguments

path

The user's value.

arg

Name of the argument, as it appears in the user's call.

must_exist

Require the file to exist, for a path that is read.

Value

path, unchanged.