Help in porting a toolbox

[Mathieu Dubois]

Hello,

I'm a new Octave user (I have some experience using Matlab).

I wanted to port the SOM toolbox (see: http://www.cis.hut.fi/somtoolbox/) to 
Octave.
The code is a bit old but it works under Matlab 2008a (I'm stick to this 
version which is one of the reason why I want to leave Matlab).

I have some problems with code involving (s)scanf. I have read that there are a 
lot of differences between Octave and Matlab in this area.
The problematic line can be found in som_read_data.m, line 225:
  [s, c, e, n] = sscanf(li, '%s%[^ \t]');
The goal of the line is to read the header of a file which contains the data 
label.
The variable li (the line) contains "SepalL SepalW PetalL PetalW".
Under Matlab, s contains "SepalL" (the first label) and the variable n (which 
causes the error) contains 8.
Under Octave, s contains the correct value but n is 0.
This value creates an error in line 226 (because n is used to acces elements of 
li).

I have used the "C" form which is closer to Matlab if I understand correctly:
[s, c, n] = sscanf(li, '%s%[^ \t]', "C");
Then n contains 1 (cause there is only 1 match).

What is the best way to emulate matlab behavior?

The code need to work on Matlab too.
Is there a way to know you're under octave (something like a ISOCTAVE 
variable)? That would be a simple way to write conditionnal code like
if exists('ISOCTAVE')
 % Octave specific code
else
 % Matlab specific code
end

Thanks in advance,
Mathieu