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如何使用C在Windows中单独获取用户和系统环境变量

[英]How to separately get user and system environment variables in Windows with C

原文 2017-07-11 09:02:55 4 1 c/ windows/ winapi/ environment-variables

I would like to be able to separately query user and system environment variables. 我希望能够单独查询用户和系统环境变量。
Like they are shown in the Environment Variables dialog. 就像它们显示在Environment Variables对话框中一样。

By using the GetEnvironmentVariable and *getenv* functions I can only get values obtained after merging the two sets of variables, with the user-defined ones taking precedence. 通过使用GetEnvironmentVariable和*getenv*函数，我只能获得合并两组变量后获得的值，其中用户定义的变量优先。
Just like the set command shows on the command line. 就像在命令行上显示set命令一样。

This capability would be useful to avoid silently falling back on a system-defined variable when a user-defined one with the same name doesn't exist. 当用户定义的具有相同名称的变量不存在时，此功能可用于避免以静默方式回退到系统定义的变量。

Even an undocumented API would be fine. 即使是未记录的API也没关系。

1 个解决方案

ExpandEnvironmentStringsForUser ( CreateEnvironmentBlock ) will only use the system variables if you pass a NULL token handle but I don't think there is a function that only gives you the user variables so you have to manually read them from the registry. 如果传递NULL标记句柄， ExpandEnvironmentStringsForUser （ CreateEnvironmentBlock ）将仅使用系统变量，但我认为没有一个函数只提供用户变量，因此您必须从注册表中手动读取它们。

Remember that there are two user variable keys in the registry: Environment and Volatile Environment . 请记住，注册表中有两个用户变量键： Environment Volatile Environment 。 The volatile key even has sub keys on some versions of Windows. 易失性键甚至在某些版本的Windows上具有子键。