Added embryonic description of fcntl.lockf(). Added pointer to that

in posixfile (which is obsolescent).

Doc/lib/libfcntl.tex

@@ -42,6 +42,11 @@ See the Unix manual for details.  (On some systems, this function is
 emulated using \code{fcntl}.)
 \end{funcdesc}
 
+\begin{funcdesc}{lockf}{fd\, code\, \optional{len\, \optional{start\, \optional{whence}}}}
+This is a wrapper around the \code{F_SETLK} and \code{F_SETLKW}
+\code{fcntl()} calls.  See the Unix manual for details.
+\end{funcdesc}
+
 If the library modules \code{FCNTL} or \code{IOCTL} are missing, you
 can find the opcodes in the C include files \code{sys/fcntl} and
 \code{sys/ioctl}. You can create the modules yourself with the h2py

Doc/lib/libposixfile.tex

@@ -3,6 +3,10 @@
 \bimodindex{posixfile}
 \indexii{posix}{file object}
 
+\emph{Note:} This module will become obsolete in a future release.
+The locking operation that it provides is done better and more
+portably by the \code{fcntl.lockf()} call.
+
 This module implements some additional functionality over the built-in
 file objects.  In particular, it implements file locking, control over
 the file flags, and an easy interface to duplicate the file object.

Doc/libfcntl.tex

@@ -42,6 +42,11 @@ See the Unix manual for details.  (On some systems, this function is
 emulated using \code{fcntl}.)
 \end{funcdesc}
 
+\begin{funcdesc}{lockf}{fd\, code\, \optional{len\, \optional{start\, \optional{whence}}}}
+This is a wrapper around the \code{F_SETLK} and \code{F_SETLKW}
+\code{fcntl()} calls.  See the Unix manual for details.
+\end{funcdesc}
+
 If the library modules \code{FCNTL} or \code{IOCTL} are missing, you
 can find the opcodes in the C include files \code{sys/fcntl} and
 \code{sys/ioctl}. You can create the modules yourself with the h2py

Doc/libposixfile.tex

@@ -3,6 +3,10 @@
 \bimodindex{posixfile}
 \indexii{posix}{file object}
 
+\emph{Note:} This module will become obsolete in a future release.
+The locking operation that it provides is done better and more
+portably by the \code{fcntl.lockf()} call.
+
 This module implements some additional functionality over the built-in
 file objects.  In particular, it implements file locking, control over
 the file flags, and an easy interface to duplicate the file object.