fails:File.open opens the file when passed mode, num and permissions
fails:File.open opens the file when passed mode, num, permissions and block
fails:File.open opens the existing file, does not change permissions even when they are specified
fails:File.open raises an Errorno::EEXIST if the file exists when open with File::CREAT|File::EXCL
fails:File.open raises an Errno::EACCES when opening non-permitted file
fails:File.open raises an Errno::EACCES when opening read-only file
fails:File.open opens a file for binary read-write starting at the beginning of the file
fails:File.open raises a SystemCallError if passed an invalid Integer type
fails:File.open with a block does not raise error when file is closed inside the block
fails:File.open with a block does not propagate StandardErrors produced by close
fails:File.open on a FIFO opens it as a normal file
fails:File.open when passed a file descriptor opens a file
fails:File.open when passed a file descriptor opens a file when passed a block
fails:File.open opens directories
fails:File.open opens a file with a file descriptor d and a block
fails:File.open with a block propagates StandardErrors produced by close
