function directory=FindFolder(name)
% directory=FindFolder(name)
% Searches the Matlab 'path' for the path to the named folder.
% There may be no matches, one match, or multiple matches.
% Each unique match appears as a row in "directory".
% If there are no matches then "directory" will be an empty matrix.
% Matching ignores case.
% You should DEBLANK a row of "directory" before using it.
%
% Also see Matlab's MKDIR, TEMPDIR, ISDIR, LOOKFOR, WHAT.
% Try HELP PsychFiles.

% 7/26/96  dgp Wrote it.
% 12/10/01 awi Set ignoreCase to 1 always.
% 4/13/02  dgp Updated to use Matlab's predefined separator symbols.
% 6/05/21  dhb Order of arguments to strfind was backwards. I don't see how
%              this ever worked.

% Matlab predefines these:
% PATHSEP = path separator character
% FILESEP = directory separator character

ignoreCase=1;
paths=[path pathsep];
if ignoreCase
    n=lower(name);
    p=lower(paths);
else
    n=name;
    p=paths;
end
pathIndex=[1 1+strfind(p,pathsep)];
nameIndex=[strfind(p,[filesep n filesep]) strfind(p,[filesep n pathsep])];
clear n p
if isempty(nameIndex)
    directory=[];
else
    nIndex=nameIndex(1);
    pIndex=pathIndex(max(find(pathIndex<=nIndex)));
    directory=[paths(pIndex:nIndex+length(name)) filesep];
    for i=2:length(nameIndex)
        nIndex=nameIndex(i);
        pIndex=pathIndex(max(find(pathIndex<=nIndex)));
        new=[paths(pIndex:nIndex+length(name)) filesep];
        unique=1;
        for j=1:size(directory,1)
            if streq(deblank(directory(j,:)),new)
                unique=0;
                break
            end
        end
        if unique
            directory=char(directory,new);
        end
    end
end

% FindFolder always succeeds. "directory" will have zero to many rows,
% each row containing a unique match.

% What follows is optional code that you may want to add to your program, after
% it calls FindFolder, to give an error unless there was exactly one match.
if 0
    if isempty(directory)
        error(['Can''t find any ''' name ''' folder in the Matlab path.']);
    end
    if size(directory,1)>1
        for i=1:size(directory,1)
            disp(['DUPLICATE: ''' deblank(directory(i,:)) '''']);
        end
        error(['Found more than one ''' name ''' folder in the Matlab path.']);
    end
end