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diff m-toolbox/html_help/highlight/highlight.m @ 0:f0afece42f48

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author Daniele Nicolodi <nicolodi@science.unitn.it>
date Wed, 23 Nov 2011 19:22:13 +0100
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/html_help/highlight/highlight.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,588 @@
+function highlight(mfile,options,outfile)
+%HIGHLIGHT - Syntax Highlighting of Matlab M-files in HTML, LaTeX, RTF and XML.
+%  HIGHLIGHT(MFILE) takes an M-file MFILE in input and writes on disk an HTML
+%  file with the same basename ('foo.m' => 'foo.html') adding colored syntax 
+%  highlighting on comment, string and Matlab keyword elements.
+%  HIGHLIGHT(MFILE,OPTIONS) with OPTIONS being string 'html', 'xhtml', 'tex', 
+%  'rtf' or 'xml', allows to choose the output format between HTML, XHTML, LaTeX
+%  RTF or XML. The same rule is used to determine the name of the output file.
+%  HIGHLIGHT(MFILE,OPTIONS) allows to specify some options in a structure:
+%     options.type - Output file type 
+%             [ {'html'} | 'tex' | 'rtf' | 'xml' | 'xhtml']
+%     options.tabs - Replace '\t' in source code by n white space
+%                           [ 0 ... {4}  ... n]
+%     options.linenb - Display line number in front of each line [ 0 | {1} ]
+%  HIGHLIGHT(MFILE,OPTIONS,OUTFILE) allows to specify the name of the output 
+%  file. OUTFILE can also be a file handle. In that case, no header will be 
+%  written, only the highlighted Matlab code will be sent to the OUTFILE stream.
+
+%  Output file can be customized (font style, font color, font size, ...):
+%     o HTML: use CSS (Cascading Style Sheets) to define 'comment', 'string', 
+%       'keyword', 'cont' and 'code' SPAN elements and 'mcode' PRE tag.
+%     o LaTeX: packages 'alltt' and 'color' are required, you can modify colors
+%       in defining colors 'string', 'comment' and 'keyword' using command
+%                      \definecolor{mycolor}{rgb}{a,b,c}
+%     o RTF: Colors are defined in the Color Table at the beginning of the
+%       document. See Rich Text Format Specifications for more details:
+%       <http://msdn.microsoft.com/library/en-us/dnrtfspec/html/rtfspec.asp>
+%     o XML: you will find the DTD of the resulting XML file in matlab.dtd
+%       You can then use XSL to transform your XML file in what you want.
+%       For example, mat2html.xsl transforms your XML file in HTML as it would
+%       be if you would have used highlight.m to to so.
+%       On Matlab 6.5, the command is:
+%               xslt highlight.xml mat2html.xsl highlight.html
+%       On Linux, using libxslt <http://xmlsoft.org/XSLT/>, the command is: 
+%               xsltproc -o highlight.html mat2html.xsl highlight.xml
+
+%  Copyright (C) 2003 Guillaume Flandin <Guillaume@artefact.tk>
+%  $Revision: 1.1 $Date: 2010/02/24 10:14:32 $
+
+%  This program is free software; you can redistribute it and/or
+%  modify it under the terms of the GNU General Public License
+%  as published by the Free Software Foundation; either version 2
+%  of the License, or any later version.
+% 
+%  This program is distributed in the hope that it will be useful,
+%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%  GNU General Public License for more details.
+% 
+%  You should have received a copy of the GNU General Public License
+%  along with this program; if not, write to the Free Software
+%  Foundation Inc, 59 Temple Pl. - Suite 330, Boston, MA 02111-1307, USA.
+
+% Suggestions for improvement and fixes are always welcome, although no
+% guarantee is made whether and when they will be implemented.
+% Send requests to Guillaume@artefact.tk
+
+% TODO % Improve distinction between 'end' keyword and array subscript
+% TODO % Smart indentation is *very* buggy (unusable => undocumented)
+% TODO % Handle wrap mode for long lines in LaTeX mode (and in HTML)
+% TODO % Improve the XSL transformer from XML to LaTeX
+
+%- Set up options
+error(nargchk(1,3,nargin));
+
+opt = struct('type',   'html', ...
+			 'tabs',   4, ...
+             'linenb', 1, ...
+			 'indent', 0);
+if nargin >= 2
+	if isstruct(options)
+		names = fieldnames(options);
+		for i=1:length(names)
+			opt = setfield(opt,names{i},getfield(options,names{i}));
+		end
+	elseif ischar(options)
+		opt.type = options;
+	else
+		error('Bad input argument.');
+	end
+end
+if strcmp(lower(opt.type),'latex'), opt.type = 'tex'; end
+if strcmp(lower(opt.type),'xml'), opt.linenb = 1; end
+
+%- If no output filename is provided, one is chosen according to mfile
+if nargin < 3
+	[pathstr, name, ext] = fileparts(mfile);
+	outfile = fullfile(pathstr, [name, '.' lower(opt.type)]);
+end
+
+%- If an output filename is provided, a standard header is created
+if ischar(outfile)
+	outfid = fopen(outfile,'wt');
+	if outfid == -1
+		error(sprintf('Cannot open ',outfile));
+	end
+	feval([lower(opt.type) '_file_start'],outfid,mfile);
+%- Otherwise a file handle is provided
+else
+	outfid = outfile;
+end
+
+%- Open the Matlab mfile to be highlighted
+mfid = fopen(mfile,'rt');
+if mfid == -1
+	error(sprintf('Cannot open ',mfile));
+end
+
+%- Write the syntax highlighted mfile code in the output file
+write_highlighted_code(mfid,outfid,opt)
+
+%- Close the Matlab mfile and potentially the output file
+fclose(mfid);
+if ischar(outfile), 
+	feval([lower(opt.type) '_file_end'],outfid);
+	fclose(outfid); 
+end
+
+%===============================================================================
+function write_highlighted_code(mfid,outfid,opt)
+	matlabKeywords = getMatlabKeywords;
+	mKeySort       = getMatlabKeywordsSorted;
+	out_format     = feval([lower(opt.type) '_format']);
+	strtok_delim   = sprintf(' \t\n\r(){}[]<>+-*~!|\\@&/.,:;="''%');
+	
+	fprintf(outfid,out_format.pre_start);
+	nbline = 1;
+	nbblanks = 0;
+	flagnextline = 0;
+	while 1
+		tline = fgetl(mfid);
+		if ~ischar(tline), break, end
+		tline = feval([lower(opt.type) '_special_char'],horztab(tline,opt.tabs));
+		%- Display the line number at each line
+		if opt.linenb
+			fprintf(outfid,out_format.nb_line,nbline);
+			nbline = nbline + 1;
+		end
+		%- Remove blanks at the beginning of the line
+		if opt.indent
+			tline = fliplr(deblank(fliplr(tline)));
+		end
+		nbblanks = nbblanks + flagnextline;
+		flagnextline = 0;
+		%- Split code into meaningful chunks
+		splitc = splitcode(tline);
+		newline = '';
+		for i=1:length(splitc)
+			if isempty(splitc{i})
+			elseif splitc{i}(1) == ''''
+				newline = [newline sprintf(out_format.string,splitc{i})];
+			elseif splitc{i}(1) == '%'
+				newline = [newline sprintf(out_format.comment,splitc{i})];
+			elseif ~isempty(strmatch('...',splitc{i}))
+				newline = [newline sprintf(out_format.cont,'...')];
+				if ~isempty(splitc{i}(4:end))
+					newline = [newline sprintf(out_format.comment,splitc{i}(4:end))];
+				end
+			else
+				%- Look for Matlab keywords
+				r = splitc{i};
+				stringcode = '';
+				while 1
+					[t,r,q] = strtok(r,strtok_delim);
+					stringcode = [stringcode q];
+					if isempty(t), break, end;
+					isNextIncr  = any(strcmp(t,mKeySort.nextincr));
+					isNextIncr2 = any(strcmp(t,mKeySort.nextincr2));
+					isCurrDecr  = any(strcmp(t,mKeySort.currdecr));
+					isNextDecr  = any(strcmp(t,mKeySort.nextdecr));
+					isOther     = any(strcmp(t,mKeySort.other));
+					if isNextDecr % if strcmp(t,'end')
+						% 'end' is keyword or array subscript ?
+						rr = fliplr(deblank(fliplr(r)));
+						icomma = strmatch(',',rr);
+						isemicolon = strmatch(';',rr);
+						if ~(isempty(rr) | ~isempty([icomma isemicolon]))
+							isNextDecr = 0;
+						else
+							nbblanks = nbblanks - 1;
+							flagnextline = flagnextline + 1;
+						end
+						% TODO % false detection of a([end,1])
+					end
+					if isNextIncr, flagnextline = flagnextline + 1; end
+					if isNextIncr2, flagnextline = flagnextline + 2; end
+					if isNextDecr, flagnextline = flagnextline - 1; end
+					if isCurrDecr, nbblanks = nbblanks - 1; end
+					% if any(strcmp(t,matlabKeywords))
+					if isNextIncr | isNextIncr2 |isCurrDecr | isNextDecr | isOther
+						if ~isempty(stringcode)
+							newline = [newline sprintf(out_format.code,stringcode)];
+							stringcode = '';
+						end
+						newline = [newline sprintf(out_format.keyword,t)];
+					else
+						stringcode = [stringcode t];
+					end
+				end
+				if ~isempty(stringcode)
+					newline = [newline sprintf(out_format.code,stringcode)];
+				end
+			end
+		end
+		if ~opt.indent, nbblanks = 0; end
+		%- Print the syntax highlighted line
+		fprintf(outfid,out_format.line,[blanks(nbblanks*opt.tabs) newline]);
+	end
+	fprintf(outfid,out_format.pre_end);
+
+%===============================================================================
+%                                  HTML FORMAT                                 %
+%===============================================================================
+function html_file_start(fid,mfile)
+	fprintf(fid,[ ...
+	'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"\n' ...
+    '\t"http://www.w3.org/TR/REC-html40/loose.dtd">\n' ...
+	'<html>\n<head>\n<title>%s</title>\n' ...
+	'<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">\n' ...
+	'<meta name="generator" content="highlight.m &copy; 2003 Guillaume Flandin">\n' ...
+	'<style type="text/css">\n' ...
+	'  .comment {color: #228B22;}\n' ...
+	'  .string {color: #B20000;}\n' ...
+	'  .keyword, .cont {color: #0000FF;}\n' ...
+	'  .cont {text-decoration: underline;}\n' ...
+	'  .code {color: #000000;}\n' ...
+	'</style>\n' ...
+	'</head>\n<body>\n'],mfile);
+
+%-------------------------------------------------------------------------------
+function html_file_end(fid)
+	fprintf(fid,'\n</body>\n</html>');
+
+%-------------------------------------------------------------------------------
+function format = html_format
+	format.string    = '<span class="string">%s</span>';
+	format.comment   = '<span class="comment">%s</span>';
+	format.code      = '%s'; %'<span class="code">%s</span>';
+	format.keyword   = '<span class="keyword">%s</span>';
+	format.cont      = '<span class="cont">%s</span>';
+	format.pre_start = '<pre class="mcode">';
+	format.pre_end   = '</pre>\n';
+	format.nb_line   = '%04d ';
+	format.line      = '%s\n';
+
+%-------------------------------------------------------------------------------
+function str = html_special_char(str)
+	%- See http://www.w3.org/TR/html4/charset.html#h-5.3.2
+	str = strrep(str,'&','&amp;');
+	str = strrep(str,'<','&lt;');
+	str = strrep(str,'>','&gt;');
+	str = strrep(str,'"','&quot;');
+
+%===============================================================================
+%                                  XHTML FORMAT                                %
+%===============================================================================
+function xhtml_file_start(fid,mfile)
+	fprintf(fid,[ ...
+	'<?xml version="1.0"?>\n' ...
+	'<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" ' ...
+	'"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">\n' ...
+	'<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">\n' ...
+	'<head>\n<title>%s</title>\n' ...
+	'<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />\n' ...
+	'<meta name="generator" content="highlight.m &copy; 2003 Guillaume Flandin" />\n' ...
+	'<style type="text/css">\n' ...
+	'  .comment {color: #228B22;}\n' ...
+	'  .string {color: #B20000;}\n' ...
+	'  .keyword, .cont {color: #0000FF;}\n' ...
+	'  .cont {text-decoration: underline;}\n' ...
+	'  .code {color: #000000;}\n' ...
+	'</style>\n' ...
+	'</head>\n<body>\n'],mfile);
+
+%-------------------------------------------------------------------------------
+function xhtml_file_end(fid)
+	fprintf(fid,'\n</body>\n</html>');
+
+%-------------------------------------------------------------------------------
+function format = xhtml_format
+	format.string    = '<span class="string">%s</span>';
+	format.comment   = '<span class="comment">%s</span>';
+	format.code      = '%s'; %'<span class="code">%s</span>';
+	format.keyword   = '<span class="keyword">%s</span>';
+	format.cont      = '<span class="cont">%s</span>';
+	format.pre_start = '<pre class="mcode">';
+	format.pre_end   = '</pre>\n';
+	format.nb_line   = '%04d ';
+	format.line      = '%s\n';
+
+%-------------------------------------------------------------------------------
+function str = xhtml_special_char(str)
+	%- See http://www.w3.org/TR/html4/charset.html#h-5.3.2
+	str = strrep(str,'&','&amp;');
+	str = strrep(str,'<','&lt;');
+	str = strrep(str,'>','&gt;');
+	str = strrep(str,'"','&quot;');
+
+
+%===============================================================================
+%                                   XML FORMAT                                 %
+%===============================================================================
+function xml_file_start(fid,mfile)
+	fprintf(fid,[ ...
+	'<?xml version="1.0" encoding="iso-8859-1" ?>\n' ...
+	'<!DOCTYPE mfile SYSTEM "matlab.dtd">\n' ...
+	'<mfile name="%s">\n'],mfile);
+
+%-------------------------------------------------------------------------------
+function xml_file_end(fid)
+	fprintf(fid,'</mfile>');
+
+%-------------------------------------------------------------------------------
+function format = xml_format
+	format.string    = '<string>%s</string>';
+	format.comment   = '<comment>%s</comment>';
+	format.code      = '%s'; %'<code>%s</code>';
+	format.keyword   = '<keyword>%s</keyword>';
+	format.cont      = '<cont>%s</cont>';
+	format.pre_start = '';
+	format.pre_end   = '';
+	format.nb_line   = '<line nb="%04d ">';
+	format.line      = '%s</line>\n';
+
+%-------------------------------------------------------------------------------
+function str = xml_special_char(str)
+	%- See http://www.w3.org/TR/REC-xml#sec-predefined-ent
+	str = strrep(str,'&','&amp;');
+	str = strrep(str,'<','&lt;');
+	str = strrep(str,'>','&gt;');
+	str = strrep(str,'"','&quot;');
+	%str = strrep(str,'''','&apos;');
+	
+%===============================================================================
+%                                  LaTeX FORMAT                                %
+%===============================================================================
+function tex_file_start(fid,mfile)
+	fprintf(fid,['\\documentclass[a4paper,10pt]{article}\n' ...
+				 '    \\usepackage{alltt}\n' ...
+				 '    \\usepackage{color}\n' ...
+				 '    \\usepackage{fullpage}\n' ...
+				 '    \\definecolor{string}{rgb}{0.7,0.0,0.0}\n' ...
+				 '    \\definecolor{comment}{rgb}{0.13,0.54,0.13}\n' ...
+				 '    \\definecolor{keyword}{rgb}{0.0,0.0,1.0}\n' ...
+				 '    \\title{%s}\n' ...
+				 '    \\author{\\textsc{Matlab}, The Mathworks, Inc.}\n' ...
+				 '\\begin{document}\n' ...
+				 '\\maketitle\n'],mfile);
+
+%-------------------------------------------------------------------------------
+function tex_file_end(fid)
+	fprintf(fid,'\\end{document}');
+
+%-------------------------------------------------------------------------------
+function format = tex_format
+	format.string    = '\\textcolor{string}{%s}';
+	format.comment   = 'textcolor{comment}{%s}'; % '%' has been replaced by '\%'
+	format.code      = '%s';
+	format.keyword   = '\\textcolor{keyword}{%s}';
+	format.cont      = '\\textcolor{keyword}{\\underline{%s}}';
+	format.pre_start = '\\begin{alltt}\n';
+	format.pre_end   = '\\end{alltt}\n';
+	format.nb_line   = '%04d ';
+	format.line      = '%s\n';
+
+%-------------------------------------------------------------------------------
+function str = tex_special_char(str)
+	% Special characters: # $ % & ~ _ ^ \ { }
+	str = strrep(str,'\','\(\backslash\)'); % $\backslash$ or \textbackslash or \verb+\+
+	str = strrep(str,'#','\#');
+	str = strrep(str,'$','\$');
+	str = strrep(str,'%','\%');
+	str = strrep(str,'&','\&');
+	str = strrep(str,'_','\_');
+	str = strrep(str,'{','\{');
+	str = strrep(str,'}','\}');
+	str = strrep(str,'^','\^{}');
+	str = strrep(str,'~','\~{}'); % or \textasciitilde
+
+%===============================================================================
+%                                   RTF FORMAT                                 %
+%===============================================================================
+function rtf_file_start(fid,mfile)
+	fprintf(fid,['{\\rtf1\\ansi\n\n' ...
+				 '{\\fonttbl{\\f0\\fmodern\\fcharset0\\fprq1 Courier New;}}\n\n' ...
+				 '{\\colortbl;\n' ...
+				 '\\red0\\green0\\blue0;\n' ...
+				 '\\red0\\green0\\blue255;\n' ...
+				 '\\red33\\green138\\blue33;\n' ...
+				 '\\red178\\green0\\blue0;}\n\n' ...
+				 '{\\info{\\title %s}\n' ...
+				 '{\\author HighLight.m Copyright 2003}\n' ...
+				 '{\\creatim\\yr%s\\mo%s\\dy%s}' ...
+				 '{\\*\\manager Guillaume Flandin}\n' ...
+				 '{\\*\\company Artefact.tk}\n' ...
+				 '{\\*\\hlinkbase http://www.madic.org/download/' ... 
+				 'matlab/highlight/}}\n\n'],mfile,...
+				 datestr(date,'yyyy'),datestr(date,'mm'),datestr(date,'dd'));
+
+%-------------------------------------------------------------------------------
+function rtf_file_end(fid)
+	fprintf(fid,'}');
+
+%-------------------------------------------------------------------------------
+function format = rtf_format
+	format.string    = '{\\cf4 %s}';
+	format.comment   = '{\\cf3 %s}';
+	format.code      = '{%s}';
+	format.keyword   = '{\\cf2 %s}';
+	format.cont      = '{\\cf2 %s}';
+	format.pre_start = '{\\f0\\fs16{';
+	format.pre_end   = '}}';
+	format.nb_line   = '{%04d }';
+	format.line      = '%s\n\\par ';
+
+%-------------------------------------------------------------------------------
+function str = rtf_special_char(str)
+	str = strrep(str,'\','\\');
+	str = strrep(str,'{','\{');
+	str = strrep(str,'}','\}');
+
+%===============================================================================
+%                                 MATLAB KEYWORDS                              %
+%===============================================================================
+function matlabKeywords = getMatlabKeywords
+	%matlabKeywords = iskeyword; % Matlab R13
+	matlabKeywords = {'break', 'case', 'catch', 'continue', 'elseif', 'else',...
+					  'end', 'for', 'function', 'global', 'if', 'otherwise', ...
+					  'persistent', 'return', 'switch', 'try', 'while'};
+					  
+%-------------------------------------------------------------------------------
+function mKeySort = getMatlabKeywordsSorted
+	mKeySort.nextincr = {'for', 'while', 'if', 'else', 'elseif', ...
+						 'case', 'otherwise', 'try', 'catch'};
+	mKeySort.nextincr2 = {'switch'};
+	mKeySort.currdecr = {'else', 'elseif', 'case', 'otherwise', 'catch'};
+	mKeySort.nextdecr = {'end'};
+	mKeySort.other    = {'break', 'continue', 'function', 'global', ...
+						 'persistent', 'return'};
+
+%===============================================================================
+%                               HANDLE TAB CHARACTER                           %
+%===============================================================================
+function str = horztab(str,n)
+	%- For browsers, the horizontal tab character is the smallest non-zero 
+	%- number of spaces necessary to line characters up along tab stops that are
+	%- every 8 characters: behaviour obtained when n = 0.
+	if n > 0
+		str = strrep(str,sprintf('\t'),blanks(n));
+	end
+
+%===============================================================================
+%                                MATLAB CODE PARSER                            %
+%===============================================================================
+function splitc = splitcode(code)
+	%Split a line of  Matlab code in string, comment and other
+
+	%- Label quotes in {'transpose', 'beginstring', 'midstring', 'endstring'}
+	iquote = findstr(code,'''');
+	quotetransp = [double('_''.)}]') ...
+				   double('A'):double('Z') ...
+				   double('0'):double('9') ...
+				   double('a'):double('z')];
+	flagstring = 0;
+	flagdoublequote = 0;
+	jquote = [];
+	for i=1:length(iquote)
+		if ~flagstring
+			if iquote(i) > 1 & any(quotetransp == double(code(iquote(i)-1)))
+				% => 'transpose';
+			else
+				% => 'beginstring';
+				jquote(size(jquote,1)+1,:) = [iquote(i) length(code)];
+				flagstring = 1;
+			end
+		else % if flagstring
+			if flagdoublequote | ...
+			   (iquote(i) < length(code) & strcmp(code(iquote(i)+1),''''))
+				% => 'midstring';
+				flagdoublequote = ~flagdoublequote;
+			else
+				% => 'endstring';
+				jquote(size(jquote,1),2) = iquote(i);
+				flagstring = 0;
+			end
+		end
+	end
+
+	%- Find if a portion of code is a comment
+	ipercent = findstr(code,'%');
+	jpercent = [];
+	for i=1:length(ipercent)
+		if isempty(jquote) | ...
+		   ~any((ipercent(i) > jquote(:,1)) & (ipercent(i) < jquote(:,2)))
+			jpercent = [ipercent(i) length(code)];
+			break;
+		end
+	end
+
+	%- Find continuation punctuation '...'
+	icont = findstr(code,'...');
+	for i=1:length(icont)
+		if (isempty(jquote) | ...
+			~any((icont(i) > jquote(:,1)) & (icont(i) < jquote(:,2)))) & ...
+			(isempty(jpercent) | ...
+			icont(i) < jpercent(1))
+			jpercent = [icont(i) length(code)];
+			break;
+		end
+	end
+
+	%- Remove strings inside comments
+	if ~isempty(jpercent) & ~isempty(jquote)
+		jquote(find(jquote(:,1) > jpercent(1)),:) = [];
+	end
+
+	%- Split code in a cell array of strings
+	icode = [jquote ; jpercent];
+	splitc = {};
+	if isempty(icode)
+		splitc{1} = code;
+	elseif icode(1,1) > 1
+		splitc{1} = code(1:icode(1,1)-1);
+	end
+	for i=1:size(icode,1)
+		splitc{end+1} = code(icode(i,1):icode(i,2));
+		if i < size(icode,1) & icode(i+1,1) > icode(i,2) + 1
+			splitc{end+1} = code((icode(i,2)+1):(icode(i+1,1)-1));
+		elseif i == size(icode,1) & icode(i,2) < length(code)
+			splitc{end+1} = code(icode(i,2)+1:end);
+		end
+	end
+	  
+%===============================================================================
+%                           MODIFIED VERSION OF STRTOK                         %
+%===============================================================================
+function [token, remainder, quotient] = strtok(string, delimiters)
+% Modified version of STRTOK to also return the quotient
+% string = [quotient token remainder]
+%STRTOK Find token in string.
+%   STRTOK(S) returns the first token in the string S delimited
+%   by "white space".   Any leading white space characters are ignored.
+%
+%   STRTOK(S,D) returns the first token delimited by one of the 
+%   characters in D.  Any leading delimiter characters are ignored.
+%
+%   [T,R] = STRTOK(...) also returns the remainder of the original
+%   string.
+%   If the token is not found in S then R is an empty string and T
+%   is same as S. 
+%
+%   Copyright 1984-2002 The MathWorks, Inc. 
+%   $Revision: 1.1 $  $Date: 2010/02/24 10:14:32 $
+
+token = []; remainder = []; quotient = string;
+
+len = length(string);
+if len == 0
+    return
+end
+
+if (nargin == 1)
+    delimiters = [9:13 32]; % White space characters
+end
+
+i = 1;
+while (any(string(i) == delimiters))
+    i = i + 1;
+    if (i > len), return, end
+end
+start = i;
+while (~any(string(i) == delimiters))
+    i = i + 1;
+    if (i > len), break, end
+end
+finish = i - 1;
+
+token = string(start:finish);
+
+if (nargout >= 2)
+    remainder = string(finish + 1:length(string));
+end
+
+if (nargout == 3 & start > 1)
+	quotient = string(1:start-1);
+else
+	quotient = [];
+end