---

winstl_environment_variable.h

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/* 
 * File:        winstl_environment_variable.h
 *
 * Purpose:     Simple class that provides access to an environment variable.
 *
 * Created:     20th December 2002
 * Updated:     11th September 2004
 *
 * Home:        http://stlsoft.org/
 *
 * Copyright (c) 2002-2004, 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.
 *
 * 



#ifndef WINSTL_INCL_H_WINSTL_ENVIRONMENT_VARIABLE
#define WINSTL_INCL_H_WINSTL_ENVIRONMENT_VARIABLE

#ifndef __STLSOFT_DOCUMENTATION_SKIP_SECTION
# define WINSTL_VER_H_WINSTL_ENVIRONMENT_VARIABLE_MAJOR     2
# define WINSTL_VER_H_WINSTL_ENVIRONMENT_VARIABLE_MINOR     0
# define WINSTL_VER_H_WINSTL_ENVIRONMENT_VARIABLE_REVISION  1
# define WINSTL_VER_H_WINSTL_ENVIRONMENT_VARIABLE_EDIT      29
#endif /* !__STLSOFT_DOCUMENTATION_SKIP_SECTION */

/* 
 * Compatibility
 */

/*
[Incompatibilies-start]
__STLSOFT_COMPILER_IS_MSVC: _MSC_VER<1200
[Incompatibilies-end]
 */

/* 
 * Includes
 */

#ifndef WINSTL_INCL_H_WINSTL
# include "winstl.h"                        // Include the WinSTL root header
#endif /* !WINSTL_INCL_H_WINSTL */

#if defined(__STLSOFT_COMPILER_IS_MSVC) && \
    _MSC_VER < 1200
# error winstl_environment_variable.h is not compatible with Visual C++ 5.0 or earlier
#endif /* _MSC_VER < 1200 */

#ifndef WINSTL_INCL_H_WINSTL_SYSTEM_VERSION
# include "winstl_filesystem_traits.h"      // Include the WinSTL get_environment_variable
#endif /* !WINSTL_INCL_H_WINSTL_SYSTEM_VERSION */
#ifndef STLSOFT_INCL_H_STLSOFT_STRING_ACCESS
# include "stlsoft_string_access.h"         // stlsoft::c_str_ptr
#endif /* !STLSOFT_INCL_H_STLSOFT_STRING_ACCESS */
#ifndef WINSTL_INCL_H_WINSTL_STRING_ACCESS
# include "winstl_string_access.h"          // winstl::c_str_ptr
#endif /* !WINSTL_INCL_H_WINSTL_STRING_ACCESS */
#ifndef STLSOFT_INCL_H_STLSOFT_AUTO_BUFFER
# include "stlsoft_auto_buffer.h"           // stlsoft::auto_buffer
#endif /* !STLSOFT_INCL_H_STLSOFT_AUTO_BUFFER */
#ifndef WINSTL_INCL_H_WINSTL_PROCESSHEAP_ALLOCATOR
# include "winstl_processheap_allocator.h"  // processheap_allocator
#endif /* WINSTL_INCL_H_WINSTL_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 */

#if !defined(__STLSOFT_COMPILER_IS_MWERKS)
stlsoft_ns_using(c_str_ptr)
#endif /* compiler */

/* 




/* 
 * basic_environment_variable
 *
 * This class converts a relative path to an absolute one, and effectively acts
 * as a C-string of its value.
 */

template<   ss_typename_param_k C
#ifdef __STLSOFT_CF_TEMPLATE_CLASS_DEFAULT_CLASS_ARGUMENT_SUPPORT
        ,   ss_typename_param_k T = filesystem_traits<C>
#else
        ,   ss_typename_param_k T /* = filesystem_traits<C> */
#endif /* __STLSOFT_CF_TEMPLATE_CLASS_DEFAULT_CLASS_ARGUMENT_SUPPORT */
        >
class basic_environment_variable
{
public:
    typedef C                                   char_type;
    typedef T                                   traits_type;
    typedef basic_environment_variable<C, T>    class_type;
    typedef ss_size_t                           size_type;

// Construction
public:
    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, m_buffer.size()) &&
            0 != m_buffer.size())
        {
            m_buffer[0] = 0;
        }
    }
#ifdef __STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT

    template<ss_typename_param_k S>
    ss_explicit_k basic_environment_variable(S const &name)
        : m_buffer(1 + traits_type::get_environment_variable(c_str_ptr(name), 0, 0))
    {
        if( 0 == traits_type::get_environment_variable(c_str_ptr(name), m_buffer, m_buffer.size()) &&
            0 != m_buffer.size())
        {
            m_buffer[0] = 0;
        }
    }
#endif /* __STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */

// Conversions
public:
    operator char_type const *() const
    {
        return m_buffer.data();
    }

// Attributes
public:
    size_type length() const
    {
        return m_buffer.size() - 1;
    }

// Members
private:
    typedef stlsoft_ns_qual(auto_buffer)<char_type, processheap_allocator<char_type> >  buffer_t;

    buffer_t    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
 */

typedef basic_environment_variable<ws_char_a_t, filesystem_traits<ws_char_a_t> >     environment_variable_a;
typedef basic_environment_variable<ws_char_w_t, filesystem_traits<ws_char_w_t> >     environment_variable_w;
typedef basic_environment_variable<TCHAR, filesystem_traits<TCHAR> >                 environment_variable;

// Unit-testing

#ifdef STLSOFT_UNITTEST

namespace unittest
{
    ss_bool_t test_winstl_environment_variable(unittest_reporter *r)
    {
        using stlsoft::unittest::unittest_initialiser;

        ss_bool_t               bSuccess    =   true;

        unittest_initialiser    init(r, "WinSTL", "environment_variable", __FILE__);

        typedef environment_variable_a  env_var_t;

        env_var_t   path("PATH");

        if(0 != strcmp(getenv("PATH"), path))
        {
            r->report("basic_environment_variable<char> failed ", __LINE__);
            bSuccess = false;
        }

        return bSuccess;
    }

    unittest_registrar    unittest_winstl_environment_variable(test_winstl_environment_variable);

} // namespace unittest

#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_H_WINSTL_ENVIRONMENT_VARIABLE */

/* 

STLSoft Libraries documentation © Synesis Software Pty Ltd, 2001-2004