Environment PATH Directories Iteration - c++

Question

I cant find any code (neither C nor C++ Boost.Filsystem) on how to iterate (parse) the directories present in the PATH environment variable in preferrably in a platform-independent way. It is not so hard to write but I want to reuse standard modules if they are available. Links or suggestions anyone?

Answer 1

This is what I used before:
const vector<string>& get_environment_PATH()
{
static vector<string> result;
if( !result.empty() )
return result;
#if _WIN32
const std::string PATH = convert_to_utf8( _wgetenv(L"PATH") ); // Handle Unicode, just remove if you don't want/need this. convert_to_utf8 uses WideCharToMultiByte in the Win32 API
const char delimiter = ';';
#else
const std::string PATH = getenv( "PATH" );
const char delimiter = ':';
#endif
if( PATH.empty() )
throw runtime_error( "PATH should not be empty" );
size_t previous = 0;
size_t index = PATH.find( delimiter );
while( index != string::npos )
{
result.push_back( PATH.substr(previous, index-previous));
previous=index+1;
index = PATH.find( delimiter, previous );
}
result.push_back( PATH.substr(previous) );
return result;
}
This only "calculates" the thing once per program run. It's not really thread-safe either, but heck, nothing environment-related is.

Answer 2

Here is my own code snippet without advanced boost libraries:
if( exe.GetLength() )
{
wchar_t* pathEnvVariable = _wgetenv(L"PATH");
for( wchar_t* pPath = wcstok( pathEnvVariable, L";" ) ; pPath ; pPath = wcstok( nullptr, L";" ) )
{
CStringW exePath = pPath;
exePath += L"\\";
exePath += exe;
if( PathFileExists(exePath) )
{
exe = exePath;
break;
}
} //for
} //if