A filename is a string.
-A pathname is a designator for a file-descriptor: the filename is
-computed using the same mechanism as the implementation would
-use to map pathnames to OS filenames internally.
+A pathname is a designator for a filename: the filename is computed
+using the same mechanism as the implementation would use to map
+pathnames to OS filenames internally.
In an implementation that supports pathnames to files on other hosts,
using mechanisms not available to the underlying OS (for example,
(read fd buffer &optional (length (length buffer))) => bytes-read
b) where C simulates "out" parameters using pointers (for instance, in
-pipe() or socketpair()) we may use multiple return values instead.
-This doesn't apply to data transfer functions that fill buffers.
+pipe() or socketpair()) these may be optional or omitted in the Lisp
+interface: if not provided, appropriate objects will be allocated and
+returned (using multiple return values if necessary).
c) some functions accept objects such as filenames or file
-descriptors. Wherver these are specified as such in the C bindings,
+descriptors. Wherever these are specified as such in the C bindings,
the Lisp interface accepts designators for them as specified in the
'Types' section above
We do not automatically translate the returned value into "Lispy"
objects - for example, SB-POSIX:OPEN returns a small integer, not a
-stream.
+stream. Exception: boolean-returning functions (or, more commonly,
+macros) do not return a C integer, but instead a lisp boolean [ or
+maybe "true"/"false" in CLtS parlance ]; the rationale behind this
+exception is that there is nothing that can be meaningfully done with
+the boolean except test for truth or falsity -- it cannot be passed
+meaningfully to other POSIX functions.
[ Rationale: This is an interface to POSIX, not a high-level interface
that uses POSIX, and many people using it will actually want to mess