xref: /freebsd/contrib/lutok/examples/hello.cpp (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 // Copyright 2012 Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 //   notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright
11 //   notice, this list of conditions and the following disclaimer in the
12 //   documentation and/or other materials provided with the distribution.
13 // * Neither the name of Google Inc. nor the names of its contributors
14 //   may be used to endorse or promote products derived from this software
15 //   without specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 
29 /// \file examples/hello.cpp
30 /// Minimal example using Lua code to print a traditional hello-world message.
31 
32 #include <cstdlib>
33 
34 #include <lutok/state.ipp>
35 
36 
37 /// Program's entry point.
38 ///
39 /// \return A system exit code.
40 int
41 main(void)
42 {
43     // Initializes a new Lua state.  Every Lua state is independent from each
44     // other.
45     lutok::state state;
46 
47     // Loads the standard library into the Lua state.  Among many other
48     // functions, this gives us access to print(), which is used below.
49     state.open_base();
50 
51     // Pushes the print() function into the Lua stack, then its only argument,
52     // and then proceeds to execute it within the Lua state.
53     state.get_global("print");
54     state.push_string("Hello, world!");
55     state.pcall(1, 0, 0);
56 
57     return EXIT_SUCCESS;
58 }
59