Porting Unix to Windows- usage of pwd.h

Question

I'm trying to compile libUnihan code with MinGW, but have run into a function which requires porting. The purpose of the function is to get a canonical path representation. It uses `pwd.h` (which is POSIX, and MinGW isn't) so it can account for the use of '~' to mean the home directory by retrieving a `passwd` struct, which contains `pw_dir`. I did find a little information here, and a port of `realpath` here, but I am still entirely at a loss as to how to deal with this. With MinGW, I still have a home directory represented by `~` and located at `/home/nate`, but since it isn't POSIX, I don't have `pwd.h` to help me find where this home directory is. Q: How can I port the function below to work properly with MinGW? ``` /** * Return the canonicalized absolute pathname. * * It works exactly the same with realpath(3), except this function can handle the path with ~, * where realpath cannot. * * @param path The path to be resolved. * @param resolved_path Buffer for holding the resolved_p…

Accepted Answer

The purpose is to implement `~[username]/` remapping logic. This sort of code makes sense in Linux/UNIX environments, but the most common use is just to refer to the user's own home directory.

For expediency, I'd just add support for the common case - `~/` - i.e. the current user, and not bother supporting the more general case - have it fail with an obvious error in that case.

The function to get the current user's home directory is `SHGetFolderPath`.

```
#include <windows.h>

char homeDirStr[MAX_PATH];
if (SUCCEEDED(SHGetFolderPath(NULL, CSIDL_PERSONAL, NULL, 0, homeDirStr))) {
    // Do something with the path
} else {
    // Do something else
}
```

In the case of a failed lookup of the user, the code you pasted does not try to replace that string, but simply returns `NULL`, so you could emulate that.

Porting Unix to Windows- usage of pwd.h

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