If the path passed corresponds to an executable, it tries to find its path using Sys.which(). Expansion of '~' in Windows follows the definition of fs::path_expand() rather than base::path.expand(). This function tries really hard to create canonical paths.
path_rel2abs(path, cwd = getwd())
Arguments
path: (character(1)) Character string representing a relative path.
cwd: (character(1)) Current working directory.
Returns
(character(1)) Character string representing the absolute path