busmux(outputbus,inputbuslist)

function busmux(outputbus,inputbuslist)
%BUSMUX Merges datastructures from multiple SIMULINK busses.
%
%Reads listed input bus files and outputs a third file which is a
%combination of the input files.

%William York, 12/95.
%Copyright (c) 1995 by The MathWorks, Inc.

%$Revision: 1.1 $ $Date: 1997/02/11 20:50:04 $

% disp('Entering busmux')

YES=1;
NO=0;

% Get the number of bus names in inputbuslist
[BusNames, Remainder] = strtok(inputbuslist, '|');
while ~isempty(Remainder)
  [Name, Remainder] = strtok(Remainder, '|');
  BusNames=str2mat(BusNames,Name);
end
NumBusNames=size(BusNames,1);

for (Ind=1:NumBusNames)
  eval(['[str_bus' num2str(Ind) ',siz_bus' num2str(Ind) ',str]=busread(deblank(BusNames(Ind,:)));']);
  if (isempty(eval(['siz_bus' num2str(Ind) ])))
    errstr=str2mat(['Error loading input ' num2str(Ind) ' bus file:'],['- ' str]);
    errordlg(errstr,[gcb ' Error']);
    return;
  end
end  

[str_outputbus,siz_outputbus,str]=busread(outputbus);
if (isempty(str_outputbus))
  if (exist(outputbus))
    errstr=str2mat('Error loading output bus file:',['- ' str]);
    errordlg(errstr,[gcb ' Error']);
    return;
  else
    OutputbusExisted=NO;
  end
else
  OutputbusExisted=YES;
end  

desired_str_outputbus=str2mat(str_bus1,str_bus2);
for (Ind=3:NumBusNames)
  eval(['desired_str_outputbus=str2mat(desired_str_outputbus,str_bus' num2str(Ind) ');']);
end  
desired_siz_outputbus=[siz_bus1; siz_bus2];
for (Ind=3:NumBusNames)
  eval(['desired_siz_outputbus=[desired_siz_outputbus;siz_bus' num2str(Ind) '];']);
end  

% Test or Create the outputbus file
if (OutputbusExisted==YES)
  % Check if the file is a valid combination of bus1 and bus2 - this is what the autogeneration
  % function would write out.
  if (~strcmp(desired_str_outputbus,str_outputbus) | ~isequal(desired_siz_outputbus,siz_outputbus))
    % Either the strings have been reordered or the bus file is not a valid combination of bus1 and bus2
    % Recreate the file
    disp(['Recreating file ' outputbus '.txt'])
    delete([outputbus '.txt'])
    RecreateOutputBus=YES;
  else
    RecreateOutputBus=NO;
  end
end  

if (OutputbusExisted==NO | RecreateOutputBus==YES)
  % Build a new outputbus file
  if (OutputbusExisted==NO)
    % The file did not exist, so tell the user that a new one will be created
    QuestString=str2mat(['WARNING: File ' outputbus '.txt does not exist on the MATLAB path.'], ...
      '  Click Create to create the file in the current directory automatically.', ...
      '  Click Cancel to abort and create the file by hand.');
    Response=questdlg(QuestString,'Create','Cancel');
    if (strcmp(Response,'Cancel'))
      return
    end
  end
  % Create a new file
  fid_outputbus=fopen([outputbus '.txt'],'wt');
  if (fid_outputbus < 0)
    error(['Can''t open file ' outputbus '.txt'])
  end
  % The bus file either did not exist or was not valid so create the bus file
  fprintf(fid_outputbus,'%%This file is a plain text definition for DataBus %s.\n',outputbus);
  fprintf(fid_outputbus,'%%\n');
  fprintf(fid_outputbus,'%%Type "help simbus" for more information.\n');
  fprintf(fid_outputbus,'\n');
  [NumSignals,MaxStringWidth]=size(desired_str_outputbus);
  fprintf(fid_outputbus,['%%%-' num2str(MaxStringWidth) 's%s\n'],'Name','Size');
  for (Ind=1:NumSignals)
    fprintf(fid_outputbus,['%-' num2str(MaxStringWidth) 's %d\n'],deblank(desired_str_outputbus(Ind,:)),desired_siz_outputbus(Ind));
  end  
  % Close the output file
  if (fclose(fid_outputbus) < 0)
    error(['Can''t close file ' outputbus '.txt'])
  end  
end

% disp('Leaving busmux')

% EOF busmux.m