time   calls  line
                  1 function [token, remainder] = strtok(string, delimiters)
                  2 %STRTOK Find token in string.
                  3 %   TOKEN = STRTOK(STR) returns the first token in the string STR delimited
                  4 %   by white-space characters. STRTOK ignores any leading white space. 
                  5 %   If STR is a cell array of strings, TOKEN is a cell array of tokens.
                  6 %
                  7 %   TOKEN = STRTOK(STR,DELIM) returns the first token delimited by one of  
                  8 %   the characters in DELIM. STRTOK ignores any leading delimiters.
                  9 %   Do not use escape sequences as delimiters.  For example, use char(9)
                 10 %   rather than '\t' for tab.
                 11 %
                 12 %   [TOKEN,REMAIN] = STRTOK(...) returns the remainder of the original
                 13 %   string.
                 14 %
                 15 %   If the body of the input string does not contain any delimiter 
                 16 %   characters, STRTOK returns the entire string in TOKEN (excluding any
                 17 %   leading delimiter characters), and REMAIN contains an empty string.
                 18 %
                 19 %   Example:
                 20 %
                 21 %      s = '  This is a simple example.';
                 22 %      [token, remain] = strtok(s)
                 23 %
                 24 %   returns
                 25 %
                 26 %      token = 
                 27 %      This
                 28 %      remain = 
                 29 %       is a simple example.
                 30 %
                 31 %   See also ISSPACE, STRFIND, STRNCMP, STRCMP, TEXTSCAN.
                 32 
                 33 %   Copyright 1984-2009 The MathWorks, Inc.
                 34 %   $Revision: 5.14.4.8 $  $Date: 2010/08/23 23:13:29 $
                 35 
             4   36 if nargin<1  
                 37    error(message('MATLAB:strtok:NrInputArguments'));
                 38 end
                 39 
             4   40 token = ''; remainder = ''; 
                 41 
             4   42 len = length(string); 
             4   43 if len == 0 
                 44     return
                 45 end
                 46 
             4   47 if (nargin == 1) 
                 48     delimiters = [9:13 32]; % White space characters
                 49 end
                 50 
             4   51 i = 1; 
             4   52 while (any(string(i) == delimiters)) 
             4   53     i = i + 1; 
             4   54     if (i > len),  
                 55        return, 
                 56     end
             4   57 end 
                 58 
             4   59 start = i; 
             4   60 while (~any(string(i) == delimiters)) 
            12   61     i = i + 1; 
            12   62     if (i > len),  
             4   63        break,  
                 64     end
             8   65 end 
             4   66 finish = i - 1; 
                 67 
             4   68 token = string(start:finish); 
                 69 
             4   70 if (nargout == 2) 
                 71     remainder = string(finish + 1:length(string));
                 72 end