function [ibegu,iendu,jbegu,jendu,kbegu,kendu,...
          ibegv,iendv,jbegv,jendv,kbegv,kendv,...
          ibegw,iendw,jbegw,jendw,kbegw,kendw,...
          ibegp,iendp,jbegp,jendp,kbegp,kendp,...
          ibegs,iends,jbegs,jends,kbegs,kends] = read_procgrid_ucf(file,varargin)
    % [ibegu,iendu,jbegu,jendu,kbegu,kendu,...
    %  ibegv,iendv,jbegv,jendv,kbegv,kendv,...
    %  ibegw,iendw,jbegw,jendw,kbegw,kendw,...
    %  ibegp,iendp,jbegp,jendp,kbegp,kendp,...
    %  ibegs,iends,jbegs,jends,kbegs,kends] = read_procgrid_ucf(file,varargin)
    % Reads processor grids.
    % Input
    %   file              file name (if tar-mode: ustar handle)
    % ? verbosity         verbose output? (default: 0)
    % ? tarmode           read from tar-file? (default: 0)
    % Output
    %  ibegu,iendu,jbegu,jendu,kbegu,kendu    processor grid u
    %  ibegv,iendv,jbegv,jendv,kbegv,kendv    processor grid v
    %  ibegw,iendw,jbegw,jendw,kbegw,kendw    processor grid w
    %  ibegp,iendp,jbegp,jendp,kbegp,kendp    processor grid p
    %  ibegs,iends,jbegs,jends,kbegs,kends    processor grid s  
    
    % Parse optional input arguments
    par = inputParser;
    addParamValue(par,'verbosity',0,@isnumeric);
    addParamValue(par,'debug',0,@isnumeric);
    addParamValue(par,'tarmode',0,@isnumeric);
    parse(par,varargin{:});
    
    % Open file
    obj = ucf('verbosity',par.Results.verbosity,'debug',par.Results.debug);
    switch class(file)
    case 'char'
      obj.open(file);
    case {'ustar','ucfmulti'}
      ptr = file.pointer('proc.bin');
      obj.opentar(ptr);
    otherwise
      error('Input file type not supported: %s',class(file));
    end
    
    % Define sets to be read
    isDualMesh=(obj.UCFVersion>=2) && (obj.NumDataset>4);
    if isDualMesh
      sets = {'u','v','w','p','s'};
    else
      sets = {'u','v','w','p'};
    end
    nset = numel(sets);
    
    % Read raw data
    ibeg = cell(1,nset);
    iend = cell(1,nset);
    jbeg = cell(1,nset);
    jend = cell(1,nset);
    kbeg = cell(1,nset);
    kend = cell(1,nset);
    for iset=1:nset
      [data,params] = obj.readSet(1,iset);
      params = cast(params,'double');
      nxprocs = params(1);
      nyprocs = params(2);
      nzprocs = params(3);
      ibeg{iset} = data(1:nxprocs);
      iend{iset} = data(nxprocs+1:2*nxprocs);
      jbeg{iset} = data(2*nxprocs+1:2*nxprocs+nyprocs);
      jend{iset} = data(2*nxprocs+nyprocs+1:2*nxprocs+2*nyprocs);
      kbeg{iset} = data(2*nxprocs+2*nyprocs+1:2*nxprocs+2*nyprocs+nzprocs);
      kend{iset} = data(2*nxprocs+2*nyprocs+nzprocs+1:2*nxprocs+2*nyprocs+2*nzprocs);
    end
    
    % Close UCF file
    obj.close();
    
    % Reassign content from loop
    iset = find(strcmp(sets,'u'));
    ibegu = cast(ibeg{iset},'double');
    iendu = cast(iend{iset},'double');
    jbegu = cast(jbeg{iset},'double');
    jendu = cast(jend{iset},'double');
    kbegu = cast(kbeg{iset},'double');
    kendu = cast(kend{iset},'double');
    
    iset = find(strcmp(sets,'v'));
    ibegv = cast(ibeg{iset},'double');
    iendv = cast(iend{iset},'double');
    jbegv = cast(jbeg{iset},'double');
    jendv = cast(jend{iset},'double');
    kbegv = cast(kbeg{iset},'double');
    kendv = cast(kend{iset},'double');
    
    iset = find(strcmp(sets,'w'));
    ibegw = cast(ibeg{iset},'double');
    iendw = cast(iend{iset},'double');
    jbegw = cast(jbeg{iset},'double');
    jendw = cast(jend{iset},'double');
    kbegw = cast(kbeg{iset},'double');
    kendw = cast(kend{iset},'double');
    
    iset = find(strcmp(sets,'p'));
    ibegp = cast(ibeg{iset},'double');
    iendp = cast(iend{iset},'double');
    jbegp = cast(jbeg{iset},'double');
    jendp = cast(jend{iset},'double');
    kbegp = cast(kbeg{iset},'double');
    kendp = cast(kend{iset},'double');
    
    if isDualMesh
      iset = find(strcmp(sets,'s'));
      ibegs = cast(ibeg{iset},'double');
      iends = cast(iend{iset},'double');
      jbegs = cast(jbeg{iset},'double');
      jends = cast(jend{iset},'double');
      kbegs = cast(kbeg{iset},'double');
      kends = cast(kend{iset},'double');
    else
      ibegs = ibegp;
      iends = iendp;
      jbegs = jbegp;
      jends = jendp;
      kbegs = kbegp;
      kends = kendp;
    end
end