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/* /////////////////////////////////////////////////////////////////////////
* File: winstl/system/environment_variable.hpp
*
* Purpose: Simple class that provides access to an environment variable.
*
* Created: 20th December 2002
* Updated: 11th August 2010
*
* Thanks to: Pablo Aguilar for requesting size() and empty().
*
* Home: http://stlsoft.org/
*
* Copyright (c) 2002-2010, Matthew Wilson and Synesis Software
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name(s) of Matthew Wilson and Synesis Software nor the names of
* any contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ////////////////////////////////////////////////////////////////////// */
/** \file winstl/system/environment_variable.hpp
*
* \brief [C++ only] Definition of the winstl::basic_environment_variable
* class template
* (\ref group__library__system "System" Library).
*/
#ifndef WINSTL_INCL_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE
#define WINSTL_INCL_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define WINSTL_VER_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE_MAJOR 4
# define WINSTL_VER_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE_MINOR 3
# define WINSTL_VER_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE_REVISION 1
# define WINSTL_VER_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE_EDIT 65
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/* /////////////////////////////////////////////////////////////////////////
* Compatibility
*/
/*
[Incompatibilies-start]
STLSOFT_COMPILER_IS_MSVC: _MSC_VER<1200
[Incompatibilies-end]
*/
/* /////////////////////////////////////////////////////////////////////////
* Includes
*/
#ifndef WINSTL_INCL_WINSTL_H_WINSTL
# include <winstl/winstl.h>
#endif /* !WINSTL_INCL_WINSTL_H_WINSTL */
#ifndef WINSTL_INCL_WINSTL_SYSTEM_HPP_SYSTEM_TRAITS
# include <winstl/system/system_traits.hpp> // for get_environment_variable()
#endif /* !WINSTL_INCL_WINSTL_SYSTEM_HPP_SYSTEM_TRAITS */
#ifndef STLSOFT_INCL_STLSOFT_SHIMS_ACCESS_HPP_STRING
# include <stlsoft/shims/access/string.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_SHIMS_ACCESS_HPP_STRING */
#ifndef WINSTL_INCL_WINSTL_SHIMS_ACCESS_HPP_STRING
# include <winstl/shims/access/string.hpp>
#endif /* !WINSTL_INCL_WINSTL_SHIMS_ACCESS_HPP_STRING */
#ifndef STLSOFT_INCL_STLSOFT_MEMORY_HPP_AUTO_BUFFER
# include <stlsoft/memory/auto_buffer.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_MEMORY_HPP_AUTO_BUFFER */
#ifndef WINSTL_INCL_WINSTL_MEMORY_HPP_PROCESSHEAP_ALLOCATOR
# include <winstl/memory/processheap_allocator.hpp>
#endif /* !WINSTL_INCL_WINSTL_MEMORY_HPP_PROCESSHEAP_ALLOCATOR */
/* /////////////////////////////////////////////////////////////////////////
* Namespace
*/
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
/* There is no stlsoft namespace, so must define ::winstl */
namespace winstl
{
# else
/* Define stlsoft::winstl_project */
namespace stlsoft
{
namespace winstl_project
{
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* basic_environment_variable
*
* This class converts a relative path to an absolute one, and effectively acts
* as a C-string of its value.
*/
/** Represents an environment variable
*
* \ingroup group__library__system
*
* \param C The character type
* \param T The traits type. On translators that support default template arguments, this defaults to system_traits<C>
*/
template< ss_typename_param_k C
#ifdef STLSOFT_CF_TEMPLATE_CLASS_DEFAULT_CLASS_ARGUMENT_SUPPORT
, ss_typename_param_k T = system_traits<C>
#else /* ? STLSOFT_CF_TEMPLATE_CLASS_DEFAULT_CLASS_ARGUMENT_SUPPORT */
, ss_typename_param_k T /* = system_traits<C> */
#endif /* STLSOFT_CF_TEMPLATE_CLASS_DEFAULT_CLASS_ARGUMENT_SUPPORT */
>
class basic_environment_variable
{
public:
/// The char type
typedef C char_type;
/// The traits type
typedef T traits_type;
/// The allocator type
typedef processheap_allocator<C> allocator_type;
/// The current parameterisation of the type
typedef basic_environment_variable<C, T> class_type;
/// The size type
typedef ws_size_t size_type;
/// The difference type
typedef ws_ptrdiff_t difference_type;
/// The Boolean type
typedef ws_bool_t bool_type;
// Construction
public:
/// Create an instance representing the given environment variable
ss_explicit_k basic_environment_variable(char_type const* name)
: m_buffer(1 + traits_type::get_environment_variable(name, 0, 0))
{
if( 0 == traits_type::get_environment_variable(name, &m_buffer[0], m_buffer.size()) &&
0 != m_buffer.size())
{
m_buffer[0] = 0;
}
else
{
// This is necessary because GetEnvironmentVariable() does not do what
// it's documented to do
m_buffer.resize(1 + traits_type::str_len(m_buffer.data()));
}
}
#ifdef STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT
/// Create an instance representing the given environment variable
template<ss_typename_param_k S>
ss_explicit_k basic_environment_variable(S const& name)
: m_buffer(1 + traits_type::get_environment_variable(stlsoft_ns_qual(c_str_ptr)(name), 0, 0))
{
if( 0 == traits_type::get_environment_variable(stlsoft_ns_qual(c_str_ptr)(name), &m_buffer[0], m_buffer.size()) &&
0 != m_buffer.size())
{
m_buffer[0] = 0;
}
else
{
// This is necessary because GetEnvironmentVariable() does not do what
// it's documented to do
m_buffer.resize(1 + traits_type::str_len(m_buffer.data()));
}
}
#endif /* STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
// Conversions
public:
/// Implicit conversion to a non-mutable (const) pointer to the variable
operator char_type const* () const
{
return m_buffer.data();
}
/// Returns a pointer to a nul-terminated string
char_type const* c_str() const
{
return m_buffer.data();
}
// Attributes
public:
/// Returns the length of the variable
size_type length() const
{
return size();
}
/// Returns the length of the variable
size_type size() const
{
return m_buffer.size() - 1;
}
bool_type empty() const
{
return 0u == size();
}
// Members
private:
typedef stlsoft_ns_qual(auto_buffer_old)< char_type
, allocator_type
> buffer_type_;
buffer_type_ m_buffer;
// Not to be implemented
private:
basic_environment_variable(basic_environment_variable const&);
basic_environment_variable& operator =(basic_environment_variable const&);
};
/* /////////////////////////////////////////////////////////////////////////
* Typedefs for commonly encountered types
*/
/** Specialisation of the basic_environment_variable template for the ANSI character type \c char
*
* \ingroup group__library__system
*/
typedef basic_environment_variable<ws_char_a_t, system_traits<ws_char_a_t> > environment_variable_a;
/** Specialisation of the basic_environment_variable template for the Unicode character type \c wchar_t
*
* \ingroup group__library__system
*/
typedef basic_environment_variable<ws_char_w_t, system_traits<ws_char_w_t> > environment_variable_w;
/** Specialisation of the basic_environment_variable template for the Win32 character type \c TCHAR
*
* \ingroup group__library__system
*/
typedef basic_environment_variable<TCHAR, system_traits<TCHAR> > environment_variable;
/* /////////////////////////////////////////////////////////////////////////
* Helper functions
*/
#if !defined(STLSOFT_COMPILER_IS_MSVC) || \
_MSC_VER >= 1100
/** This helper function makes an environment variable without needing to
* qualify the template parameter.
*
* \ingroup group__library__system
*/
template<ss_typename_param_k C>
inline basic_environment_variable<C> make_environment_variable(C const* path)
{
return basic_environment_variable<C>(path);
}
#endif /* compiler */
////////////////////////////////////////////////////////////////////////////
// Unit-testing
#ifdef STLSOFT_UNITTEST
# include "./unittest/environment_variable_unittest_.h"
#endif /* STLSOFT_UNITTEST */
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
} // namespace winstl
# else
} // namespace winstl_project
} // namespace stlsoft
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* WINSTL_INCL_WINSTL_SYSTEM_HPP_ENVIRONMENT_VARIABLE */
/* ///////////////////////////// end of file //////////////////////////// */