dispx(str)

function dispx(str)
%dispx: Display styled string in xterm.
%   dispx(str) displays the string, str, very much like disp(str) with the
%   added feature that str can contain embedded commands to cause the text
%   to be in a bold font, underlined, blinking, colored and/or with a colored
%   background.  This function only works in an xterm that supports these
%   features via standard ANSI escape sequences.  Normally, you will have
%   started MATLAB with "matlab -nodesktop".
%
%   The commands are:
%     \bf{<text>} to display <text> in a bold font
%     \ul{<text>} to underline <text>
%     \bl{<text>} to cause <text> to blink
%     \fg{<color>}{<text>} to set the foreground color of <text> to <color>
%     \bg{<color>}{<text>} to set the background color of <text> to <color>
%
%   <color> must be a single letter to specify the following colors:
%     r => red        m => magenta
%     g => green      y => yellow
%     b => blue       k => black
%     c => cyan       w => white
%
%  In order to include the characters \, {, or }, escape them by prepending
%  a \, i.e., \\, \{ and \}.
%
%   Examples:
%     dispx('The word \ul{underlined} will be underlined.')
%     dispx('The word \fg{r}{DANGER} will be red.')
%     dispx('The word \bg{g}{NORMAL} will have a green background.')
%     dispx('\fg{y}{\bg{k}{\ul{HI!}}} will be yellow on black and underlined.')

% Version: 1.0, 11 June 2006
% Author:  Douglas M. Schwarz
% Email:   dmschwarz=ieee*org, dmschwarz=urgrad*rochester*edu
% Real_email = regexprep(Email,{'=','*'},{'@','.'})


% Input checks.
error(nargchk(1,1,nargin))
if ~ischar(str)
	error('Input argument must be a string.')
end

% Use a regular expression to split str into logical entities.
re = '(\\[a-z]{2}(\{[rgbcmykw]\})?\{)|\\\{|\\\}|\\\\|.*?';
[split,tok] = regexp(str,re,'match','tokens');

% Compute depth of nested braces.  Set colors to default.
depth = cumsum(~cellfun(@isempty,tok) - strcmp(split,'}'));
fg_color = repmat({'d'},1,length(depth));
bg_color = repmat({'d'},1,length(depth));

% Initialize some variables.
esc = char(27);
colors = {'r','g','b','c','m','y','k','w','d'};
codes = {'1','2','4','6','5','3','0','7','9'};

% Compute where depth changes in order to pair up possibly nested braces.
up = find(diff([0,depth]) == 1);
dn = find(diff(depth) == -1);
a = depth(up);
b = depth(dn);
[as,ai] = sort(a);
[bs,bi] = sort(b);
k(ai) = bi;
pairs = [up;dn(k)+1];

% Loop over number of pairs, replacing commands and closing braces with ANSI
% escape sequences.
n = size(pairs,2);
for i = 1:n
	cmd = split{pairs(1,i)};
	switch cmd(2:3)
		case 'bf'
			split{pairs(1,i)} = [esc,'[1m'];
			split{pairs(2,i)} = [esc,'[22m'];
		case 'ul'
			split{pairs(1,i)} = [esc,'[4m'];
			split{pairs(2,i)} = [esc,'[24m'];
		case 'bl'
			split{pairs(1,i)} = [esc,'[5m'];
			split{pairs(2,i)} = [esc,'[25m'];
		case 'fg'
			fg_color(pairs(1,i):pairs(2,i)-1) = {cmd(5)};
			split{pairs(1,i)} = [esc,'[3',codes{strcmp(cmd(5),colors)},'m'];
			split{pairs(2,i)} = [esc,'[3',...
				codes{strcmp(bg_color{pairs(2,i)},colors)},'m'];
		case 'bg'
			bg_color(pairs(1,i):pairs(2,i)-1) = {cmd(5)};
			split{pairs(1,i)} = [esc,'[4',codes{strcmp(cmd(5),colors)},'m'];
			split{pairs(2,i)} = [esc,'[4',...
				codes{strcmp(bg_color{pairs(2,i)},colors)},'m'];
	end
end

% Join cells back into a string.  Replace escaped characters with proper
% single characters.
str2 = [split{:}];
str2 = regexprep(str2,{'\\\\','\\{','\\}'},{'\','{','}'});

% Display result to xterm.
disp(str2)