How can I get the full name of my folder when given a short name (8.3 name) in MATLAB R2019a on Windows?

I have a short name and I like to get the full name so I can display it in a nice format on my GUI. How can I expand folders like 'C:\PROGRA~2\MIE74D~1'; to its readable format?

Answer 1

[MathWorks Support Team]

MATLAB has no built-in functionality for that. However, there are several Windows APIs you can use from MATLAB to get the fullname. One way could be ActiveX like shown below. This should work as long you do not hit the MAX_PATH length limitation on Windows:

name = 'C:\PROGRA~2\MIE74D~1';
fso = actxserver('Scripting.FileSystemObject');
if fso.FileExists(name)
  f = fso.GetFile(name);
elseif fso.FolderExists(name)
  f = fso.GetFolder(name);
end

app = actxserver('Shell.Application');
fullname = get(invoke(app.NameSpace(f.ParentFolder.Path),'ParseName',f.Name),'Path')

fso.release
app.release

Alternatively , if you have access to PowerShell you can use

name = 'C:\PROGRA~2\MIE74D~1';
[a,b] = system(sprintf('powershell.exe -Command "(Get-Item ''%s'').FullName"',name))

Or the Windows API function GetLongPathNameW

https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getlongpathnamew

used through a MEX file (callled toFullPath.cpp)

#include "mex.h"
#include "windows.h"

#define MAX_SIZE 2000

void mexFunction(int nlhs, mxArray* plhs[], int nrhs, const mxArray* prhs[]) {
    wchar_t  lpszLongPath[MAX_SIZE];
    wchar_t *tmp;
    DWORD res;
    mwSize dim[] = {1,0};

      tmp = (wchar_t*) malloc(sizeof(wchar_t) * (mxGetNumberOfElements(prhs[0])+1) );
      if (tmp == NULL) {
          plhs[0] = mxCreateCharArray((mwSize)2,dim);
          return;
      }
      wcsncpy(tmp, (wchar_t*)mxGetData(prhs[0]), mxGetNumberOfElements(prhs[0]));
      tmp[mxGetNumberOfElements(prhs[0])] = L'\0';

      res = GetLongPathNameW(tmp, lpszLongPath, MAX_SIZE);
      free(tmp);

if ( res == 0){
        plhs[0] = mxCreateCharArray((mwSize)2,dim);
        return;
    }

      dim[1] = (mwSize)res;
      plhs[0] = mxCreateCharArray((mwSize)2,dim);    
      wcsncpy((wchar_t*)mxGetData(plhs[0]),&(lpszLongPath[0]),res);
  }

compiled with

mex toFullPath.cpp

and called through:

name = 'C:\PROGRA~2\MIE74D~1';
res = toFullPath(sprintf('\\\\?\\%s',name))

Note that a \\?\ was added in front of the path to indicate a long path for Windows to avoid the MAX_PATH length limitation as mentioned in the Microsoft documentation linked above. You would need to remove that prefix in the result afterwards.