# HG changeset patch
# User jwe
# Date 831957830 0
# Node ID f44d96f6ca9ff5de0e66fab3d9512048898cc3b4
# Parent  4a0218a3ee908f9c77bdd37613f1e71c95d9bc88
[project @ 1996-05-13 03:23:50 by jwe]
Initial revision

diff -r 4a0218a3ee90 -r f44d96f6ca9f examples/hello.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/hello.cc	Mon May 13 03:23:50 1996 +0000
@@ -0,0 +1,94 @@
+// hello.cc -- example of a dynamically linked function for Octave.
+
+// To use this file, your version of Octave must support dynamic
+// linking.  To find out if your version of Octave supports dynamic
+// linking, type the command
+//
+//   octave_config_info
+//
+// at the Octave prompt.  Support for dynamic linking is included if
+// the output contains either of the lines
+//
+//   Dynamic Linking (dlopen/dlsym):          yes
+//   Dynamic Linking (shl_load/shl_findsym):  yes
+
+// To compile this file, type the command
+//
+//   mkoctfile hello
+//
+// at the shell prompt.  The script mkoctfile should have been
+// installed along with Octave.  Running it will create a file called
+// hello.oct that can be loaded by Octave.  To test the hello.oct
+// file, start Octave and type the command
+//
+//   hello ("easy as", 1, 2, 3)
+//
+// at the Octave prompt.  Octave should respond by printing
+//
+//   Hello, world!
+//   easy as
+//   1
+//   2
+//   3
+//   ans = 3
+
+// Additional examples are available in the files in the src directory
+// of the Octave distribution that use the macro DEFUN_DLD_BUILTIN.
+// Currently, this includes the files
+//
+//   balance.cc  fft.cc      hess.cc     lu.cc       schur.cc
+//   chol.cc	 fft2.cc     ifft.cc     minmax.cc   sort.cc
+//   colloc.cc   filter.cc   ifft2.cc    pinv.cc     svd.cc
+//   dassl.cc    find.cc     inv.cc      qr.cc       syl.cc
+//   det.cc	 fsolve.cc   log.cc      quad.cc
+//   eig.cc	 fsqp.cc     lsode.cc    qzval.cc
+//   expm.cc	 givens.cc   lu.cc       rand.cc
+//
+// The difference between DEFUN_DLD and DEFUN_DLD_BUILTIN is that
+// DEFUN_DLD_BUILTIN can define a built-in function that is not
+// dynamically loaded if the operating system does not support dynamic
+// linking.  To define your own dynamically linked functions you
+// should use DEFUN_DLD.
+
+#include <octave/config.h>
+
+#include <iostream.h>
+
+#include <octave/defun-dld.h>
+#include <octave/error.h>
+#include <octave/oct-obj.h>
+#include <octave/pager.h>
+#include <octave/symtab.h>
+#include <octave/variables.h>
+
+// Note, nargout is not used, so it is omitted from the argument list
+// to avoid the warning from gcc about an unused function parameter.
+
+DEFUN_DLD (hello, args, ,
+  "[...] = hello (...)\n\
+\n\
+Print greeting followed by the values of all the arguments passed.\n\
+Returns all arguments in reverse order.")
+{
+  // The list of values to return.  See the declaration in oct-obj.h
+
+  octave_value_list retval;
+
+  // This stream is normally connected to the pager.
+
+  octave_stdout << "Hello, world!\n";
+
+  // The arguments to this function are available in args.
+
+  int nargin = args.length ();
+
+  // The octave_value_list class is a zero-based array of octave_value
+  // objects.  The declaration for the octave_value class is in the
+  // file pt-const.h.  The print() method will send its output to
+  // octave_stdout, so it will also end up going through the pager.
+
+  for (int i = 0; i < nargin; i++)
+    retval (nargin-i-1) = args(i).print ();
+
+  return retval;
+}