cprintf - display formatted colored text in the Command Window

Displays sprintf-formatted strings in the Command Window using the specified color/underline style

Description

Syntax:
     count = cprintf(style,format,...)
 
Description:
CPRINTF processes the specified text using the exact same FORMAT arguments accepted by the built-in SPRINTF and FPRINTF functions.
 
CPRINTF then displays the text in the Command Window using the specified STYLE argument. The accepted styles are those used for Matlab's syntax highlighting (see: File / Preferences / Colors / M-file Syntax Highlighting Colors), and also user-defined colors.
 
The possible pre-defined STYLE names are:
 
        'Text' - default: black
        'Keywords' - default: blue
        'Comments' - default: green
        'Strings' - default: purple
        'UnterminatedStrings' - default: dark red
        'SystemCommands' - default: orange
        'Errors' - default: light red
        'Hyperlinks' - default: underlined blue
 
        'Black','Cyan','Magenta','Blue','Green','Red','Yellow','White'
 
Note: styles beginning with '-' will be underlined. For example:
   '-Blue' => underlined blue, like 'Hyperlinks'
   '-Comments' => underlined green
 
STYLE also accepts a regular Matlab RGB vector, that can be negated for underlining. For example: -[0,1,1] means underlined cyan.
 
STYLE is case-insensitive and accepts unique partial strings just like handle property names.
 
Examples (see results in the attached screenshot):
     cprintf('text', 'regular black text');
     cprintf('hyper', 'followed %s','by');
     cprintf('k', '%d colored', 4);
     cprintf('-comment','& underlined');
     cprintf('err', 'elements\n');
     cprintf('cyan', 'cyan');
     cprintf('-green', 'underlined green');
     cprintf(-[1,0,1], 'underlined magenta');
     cprintf([1,0.5,0],'and multi-\nline orange\n');
 
Bugs and suggestions:
Please send to Yair Altman (altmany at gmail dot com)
 
Warning:
This code heavily relies on undocumented and unsupported Matlab functionality. It works on Matlab 7+, but use at your own risk!
 
A technical description of the implementation can be found at: http://UndocumentedMatlab.com/blog/cprintf/

See details & current limitations in the main help section

• MATLAB release: MATLAB 7.5 (R2007b)
• Other requirements: tested on Matlab 7.1, 7.5 & 7.6 (with a few version-specific quirks detailed in the help section). Should work on all Matlab 7 versions, but I haven't tested this.
• Other Files: cprintf.m, ; license.txt

[Albert]

Great, thanks!

[Omid Khanmohamadi]

A while ago, a colleague asked me if it was possible to display in a color other than the default, in the Command Window, the values violating some thresholds in an optimization problem. My response was, "That must be doable, because MATLAB does that for, say, error messages. I will look into it." Well, you looked into it alright, Yair!

[Aurelien Queffurust]

Tested successfully with the current release R2009a under Windows and with R2008b under Linux 64-bits. Just a great submission!

[Petter]

I did not know this was possible

[Petter]

The function prints an extra white space after each string. Example:

str = 'Welcome!';
n = length(str);
for k = 1:n
    col = [k/n 0 0];
    cprintf(col,str(k));
end
fprintf('\n');

results in:
 W e l c o m e !

[Petter]

OK, I now think that may be required.

[Yair Altman]

yes Petter - this is a known limitation of CPRINTF that is mentioned in its help section as well as the TODO list (at the bottom of the file). Unfortunately, it seems that if there is no space separator, then Matlab attempts to combine the adjacent style segments, thereby overrunning the first segment's style with the second's. Adding a separator solves this. If anyone finds a workaround I'll be happy to hear. Until then it's a small price to pay...

[Alan B]

 

[Karl]

This is great! I wish Matlab documented its Java innards better. Anyway, there seems to be another small bug.

fprintf('Here: ')
cprintf('blue', 'Blue\n');

results in a blue underscore followed by the word 'Blue' in white (invisible on white background of my command window - but shows up when highlighted).

However, the same code as above, only using '-blue' instead of 'blue', works fine (gives the expected underlined blue text).

I'm using Matlab 2007b on a Linux box.

[Yair Altman]

@Karl - this is a corollary of the known issue with non-newline-terminated strings. In this case, the initial fprintf() was non-newline-terminated, getting cprintf confused...

A workaround for this case is to simply use cprintf for the initial black text, instead of fprintf:

cprintf('text', 'Here: ');
cprintf('blue', 'Blue\n');

[Mike]

There seems to be another bug, this one involving the '%' character. For example,

cprintf( 'keyword', '%% keyword\n' )

merely turns the command prompt (double chevron) blue, rather than printing '% keyword' and a newline character.

fprintf( '%% keyword\n' ), on the other hand, prints just what you would expect.

[Mike]

 

[Florian Frank]

This is a great little tool! Thank You!

[A Millo]

 

[bocovp]