在Windows上获取实际文件名(带有适当的大小写)

Question

Windows文件系统不区分大小写.如果给定一个文件/文件夹名称(例如"somefile"),我得到该文件/文件夹的实际名称(例如,如果Explorer显示它,它应该返回"SomeFile")？

我知道的一些方法,所有这些看起来都很倒退:

1. 给定完整路径,搜索路径上的每个文件夹(通过FindFirstFile).这给出了每个文件夹的正确结果.在最后一步,搜索文件本身.
2. 从句柄获取文件名(如MSDN示例中所示).这需要打开文件,创建文件映射,获取它的名称,解析设备名称等.相当复杂.它不适用于文件夹或零大小的文件.

我错过了一些明显的WinAPI电话吗？最简单的一个,比如GetActualPathName()或GetFullPathName()使用传入的大小写返回名称(例如,如果传入,则返回"程序文件",即使它应该是"Program Files").

我正在寻找原生解决方案(不是.NET).

Answer 1

在此我根据cspirz的原始答案回答我自己的问题.

这是一个给定绝对路径,相对路径或网络路径的函数,它将返回大小写的路径,就像在Windows上显示的那样.如果路径的某个组件不存在,它将从该点返回传入的路径.

它非常复杂,因为它试图处理网络路径和其他边缘情况.它在宽字符串上运行,并使用std :: wstring.是的,理论上Unicode TCHAR可能与wchar_t不同; 这是读者的练习:)

std::wstring GetActualPathName( const wchar_t* path )
{
    // This is quite involved, but the meat is SHGetFileInfo

    const wchar_t kSeparator = L'\\';

    // copy input string because we'll be temporary modifying it in place
    size_t length = wcslen(path);
    wchar_t buffer[MAX_PATH];
    memcpy( buffer, path, (length+1) * sizeof(path[0]) );

    size_t i = 0;

    std::wstring result;

    // for network paths (\\server\share\RestOfPath), getting the display
    // name mangles it into unusable form (e.g. "\\server\share" turns
    // into "share on server (server)"). So detect this case and just skip
    // up to two path components
    if( length >= 2 && buffer[0] == kSeparator && buffer[1] == kSeparator )
    {
        int skippedCount = 0;
        i = 2; // start after '\\'
        while( i < length && skippedCount < 2 )
        {
            if( buffer[i] == kSeparator )
                ++skippedCount;
            ++i;
        }

        result.append( buffer, i );
    }
    // for drive names, just add it uppercased
    else if( length >= 2 && buffer[1] == L':' )
    {
        result += towupper(buffer[0]);
        result += L':';
        if( length >= 3 && buffer[2] == kSeparator )
        {
            result += kSeparator;
            i = 3; // start after drive, colon and separator
        }
        else
        {
            i = 2; // start after drive and colon
        }
    }

    size_t lastComponentStart = i;
    bool addSeparator = false;

    while( i < length )
    {
        // skip until path separator
        while( i < length && buffer[i] != kSeparator )
            ++i;

        if( addSeparator )
            result += kSeparator;

        // if we found path separator, get real filename of this
        // last path name component
        bool foundSeparator = (i < length);
        buffer[i] = 0;
        SHFILEINFOW info;

        // nuke the path separator so that we get real name of current path component
        info.szDisplayName[0] = 0;
        if( SHGetFileInfoW( buffer, 0, &info, sizeof(info), SHGFI_DISPLAYNAME ) )
        {
            result += info.szDisplayName;
        }
        else
        {
            // most likely file does not exist.
            // So just append original path name component.
            result.append( buffer + lastComponentStart, i - lastComponentStart );
        }

        // restore path separator that we might have nuked before
        if( foundSeparator )
            buffer[i] = kSeparator;

        ++i;
        lastComponentStart = i;
        addSeparator = true;
    }

    return result;
}

再次,感谢cspirz指向SHGetFileInfo.