Free disk space

It is not obvious how to get the free space, in a directory. Here is working code from the CudaText project.

uses SysUtils;
    
    function AppDiskGetFreeSpace(const fn: string): Int64;
    begin
      {$ifdef linux}
      //this crashes on FreeBSD 12 x64
      exit(SysUtils.DiskFree(SysUtils.AddDisk(ExtractFileDir(fn))));
      {$endif}
    
      {$ifdef windows}
      exit(SysUtils.DiskFree(SysUtils.GetDriveIDFromLetter(ExtractFileDrive(fn))));
      {$endif}
    
      //cannot detect
      exit(-1);
    end;

The "fn" parameter should be any filename in the needed directory. E.g. if we need to get free space in the directory '/home/user/media', pass parameter fn as '/home/user/media/a'.

Note: code does not support Unixes other than Linux, because real tests show, that code for "$ifdef linux" part is crashing on FreeBSD 12 x64. Under FPC 3.2-fixes. Gitlab issue.

From the Free Pascal wiki, page "Disk free space", as the Internet Archive kept it on 2024-08-15, last changed on 2022-01-30. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.