_open is a version of open designed
to operate only on HFS files. _open runs faster and calls
fewer other library routines than open. Refer to open
for a full description. _open is used exactly like the standard
open function. The first argument to _open is
interpreted as an HFS filename, even if it appears to begin with a
style prefix or a leading // or both.
Copyright (c) 1998 SAS Institute Inc. Cary, NC, USA. All rights reserved.