function i = strmatch(str,strs,flag)

%STRMATCH Find possible matches for character arrays or strings.

%   STRMATCH is not recommended. Use STARTSWITH or VALIDATESTRING instead.

%

%   IDX = STRMATCH(STR, STRARRAY) looks through the rows of the character array,

%   string array, or cell array of character vectors STRARRAY to find a

%   character vector that begins with STR, and returns the matching row

%   indices. Any trailing space characters in STR or STRARRAY are ignored

%   when matching. STRMATCH is fastest when STRARRAY is a character array.

%

%   IDX = STRMATCH(STR, STRARRAY, 'exact') compares STR with each row of

%   STRARRAY, looking for an exact match of the entire text.

%   Any trailing space characters in STR or STRARRAY are ignored when

%   matching.

%

%   Examples

%     idx = strmatch('max',strvcat('max','minimax','maximum'))

%   returns idx = [1; 3] since rows 1 and 3 begin with 'max', and

%     idx = strmatch('max',strvcat('max','minimax','maximum'),'exact')

%   returns idx = 1, since only row 1 matches 'max' exactly.

%

%   See also startsWith, VALIDATESTRING, CONTAINS, STRFIND, STRCMP,

%   STRNCMP, REGEXP

%   Copyright 1984-2017 The MathWorks, Inc.

narginchk(2,3); 

missingStrs = []; 

if nargin > 2 

    flag = convertStringsToChars(flag);

end 

if isstring(strs) 

   missingStrs =  reshape(ismissing(strs), [], 1);

   strs(missingStrs) = "";

end 

if (isstring(str) && any(ismissing(str))) || ((isstring(strs) || iscell(strs)) && isempty(strs))  

    i = []; 

    return 

end 

if iscellstr(str) || isstring(str) 

    str = str(:);

    str = char(str); 

end 

if iscellstr(strs) || isstring(strs) 

    strs = strs(:); 

    strs = char(strs);  

end 

[m,n] = size(strs); 

len = numel(str); 

if (nargin==3) 

    exactMatch = true;

    if ~ischar(flag)

        warning(message('MATLAB:strmatch:InvalidFlagType'));

    elseif ~strcmpi(flag,'exact')

        warning(message('MATLAB:strmatch:InvalidFlag', flag, flag));

    end

else 

    exactMatch = false; 

end 

% Special treatment for empty STR or STRS to avoid

% warnings and error below

if len==0 

    str = reshape(str,1,len);

end  

if n==0 

    strs = reshape(strs,max(m,1),n);

    [m,n] = size(strs);

end 

if len > n 

    i = [];

else 

    if exactMatch && len < n % if 'exact' flag, pad str with blanks or nulls 

        [~,strn] = size(str);

        if strn ~= len

            error(message('MATLAB:strmatch:InvalidShape'));

        else

            % Use nulls if anything in the last column is a null.

            null = char(0); 

            space = ' ';

            if ~isempty(strs) && any(strs(:,end)==null) 

                str = [str null(ones(1,n-len))];

            else

                str = [str space(ones(1,n-len))];

            end

            len = n;

        end

    end 

    mask = true(m,1);  

    % walk from end of strs array and search for row starting with str.

    for outer = 1:m 

        for inner = 1:len 

            if (strs(outer,inner) ~= str(inner)) 

                mask(outer) = false; 

                break; % exit matching this row in strs with str. 

            end    

        end 

    end 

    mask(missingStrs) = 0; 

    i = find(mask);  

end