How to use coder.ceval to fprintf a new line ?

Matlab R2012b does not support fprint for code generation, so I am using coder.ceval to call the C fprintf function. The problem is on printing a new line, infact the instruction coder.ceval(‘fprintf’, f, ‘%lf\n‘, 10.0); produces as output in the file 10.000000\n €ÿ Moreover the instructions coder.ceval(‘fprintf’, f, ‘%lf\n‘, 10.0); coder.ceval(‘fprintf’, f, ‘%lf\n‘, 20.0); produce as output in the file 10.000000\n&bÿ20.000000\n

How is possible to get the new line?

It can be useful to underline that using printf instead of fprintf the problem does not exist

Answer 1

[Giulia Coluccini]

At the end I solved this problem after several attempts. I discovered that char(10) is the symbol to obtain a new line.

Use these lines:

fname = coder.nullcopy(char(zeros(1,32)));

coder.ceval('sprintf', coder.wref(fname), c_string('FILE_NEW.txt'));

f = coder.opaque('FILE*', 'NULL');

f = coder.ceval('fopen', fname, c_string('a')); coder.ceval('fprintf', f, c_string('%s %s'), c_string('Hello I am Giulia'), c_string(char(10)));

coder.ceval('fclose', f);

where the c_string function is defined as follows:

function y = c_string(s)

y = [s char(0)];

end

It works in Matlab R2012b.

Answer 2

[ilker ozturk]

Have you solved this problem? I get same result as your problem. If you solved this problem could you write to me? In addition, When I push to start button in matlab function, Matlab has closed. I think, its a bug but I dont know how to pass this problem. (Matlab relase is Matlab 2012a )....

Have a good day..

[Giulia Coluccini]

Yes, I solved this problem after several attempts. I discovered that char(10) is the symbol to obtain a new line.

Use these lines:

fname = coder.nullcopy(char(zeros(1,32)));

coder.ceval('sprintf', coder.wref(fname), c_string('FILE_NEW.txt'));

f = coder.opaque('FILE*', 'NULL');

f = coder.ceval('fopen', fname, c_string('a')); coder.ceval('fprintf', f, c_string('%s %s'), c_string('Hello I am Giulia'), c_string(char(10)));

coder.ceval('fclose', f);

where the c_string function is defined as follows:

function y = c_string(s)

y = [s char(0)];

end

It works in Matlab R2012b.