claw  1.9.0
dynamic_library_traits_unix.hpp
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1 /*
2  CLAW - a C++ Library Absolutely Wonderful
3 
4  CLAW is a free library without any particular aim but being useful to
5  anyone.
6 
7  Copyright (C) 2005-2011 Julien Jorge
8 
9  This library is free software; you can redistribute it and/or
10  modify it under the terms of the GNU Lesser General Public
11  License as published by the Free Software Foundation; either
12  version 2.1 of the License, or (at your option) any later version.
13 
14  This library is distributed in the hope that it will be useful,
15  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  Lesser General Public License for more details.
18 
19  You should have received a copy of the GNU Lesser General Public
20  License along with this library; if not, write to the Free Software
21  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 
23  contact: julien.jorge@stuff-o-matic.com
24 */
30 #ifndef __CLAW_DYNAMIC_LIBRARY_TRAITS_UNIX_HPP__
31 #define __CLAW_DYNAMIC_LIBRARY_TRAITS_UNIX_HPP__
32 
33 #include <claw/exception.hpp>
34 #include <dlfcn.h>
35 #include <string>
36 
37 namespace claw
38 {
44  {
45  public:
47  typedef void* handle;
48 
49  public:
55  static handle open(const std::string& name)
56  {
57  handle h = dlopen(name.c_str(), RTLD_LAZY);
58 
59  if(!valid_handle(h))
60  throw claw::exception(dlerror());
61 
62  return h;
63  }
64 
70  static handle auto_open(const std::string& name)
71  {
72  handle h = dlopen(NULL, RTLD_LAZY);
73 
74  if(!valid_handle(h))
75  throw claw::exception(dlerror());
76 
77  return h;
78  }
79 
84  static void close(handle h)
85  {
86  dlclose(h);
87  }
88 
94  template <class T>
95  static T get_symbol(handle h, const std::string& name)
96  {
97  /* HACK : ISO standard doesn't allow to cast from a pointer to an object
98  to a pointer to a function. */
99  T result;
100  *(void**)(&result) = dlsym(h, name.c_str());
101 
102  return result;
103  }
104 
110  static bool have_symbol(handle h, const std::string& name)
111  {
112  return dlsym(h, name.c_str()) != NULL;
113  }
114 
119  static bool valid_handle(handle h)
120  {
121  return h != NULL;
122  }
123 
124  }; // class dynamic_library_traits_unix
125 
128 
129 }
130 
131 #endif // __CLAW_DYNAMIC_LIBRARY_TRAITS_UNIX_HPP__
static bool valid_handle(handle h)
Tell if an handle is a valid library handle.
static handle auto_open(const std::string &name)
Open the current program.
dynamic_library_traits_unix dynamic_library_traits
The traits to access the dynamic libraries in Unix system.
static void close(handle h)
Close a library.
A simple class to use as exception with string message.
Definition: exception.hpp:42
void * handle
Type of the system handle to the library.
A simple class to use as exception with string message.
static bool have_symbol(handle h, const std::string &name)
Tell if a symbol is in the library.
static T get_symbol(handle h, const std::string &name)
Get a symbol from a library.
This is the main namespace.
Definition: application.hpp:49
Unix interface for using dynamic libraries.
static handle open(const std::string &name)
Open a library.