Converting a C char array into a Matlab String [Matlab Coder]

My intention is to show for the output of Matlab System the char_T data[ ]

I've got two questions:

• How to declare the buffer (#1) variable to store a char_T data[ ]
• (#2) How do I dump buffer data through the output

% FILE.m
function data = stepImpl(obj)
        buffer = ¿¿ ?? (#1) ;
    
        if coder.target ('Rtw')
            coder.cinclude('File_Wrapper.h');
            coder.ceval('function',obj.port, coder.wref(buffer)); 

            data = ¿¿¿ string(buffer) ??? (#2); % data - output Matlab System
        end
end

Any suggestion is welcome!

% File_Wrapper.c
void function(uint8_T port, char_T data[])
{
    if (obj.port == 1){
        char buffer[30];
        fgets(buffer, 10, uart1);
        
        snprintf (data, sizeof(buffer), "%s", buffer);
    }
}

This post dont work for me:

https://stackoverflow.com/questions/39000799/converting-a-c-char-array-into-a-matlab-string-using-matlab-coder

Thanks

Answer 1

[Swastik Sarkar]

Hi @Alvaro Navarro,

You can declare an empty buffer in MATLAB using the “char” and “zeros” functions, and then convert it back to a string using the “string” function. Here's how you can do it in your “FILE.m:”:

% FILE.m
function data = stepImpl(port)
    buffer = char(zeros(1,30)); % Adjust size accordingly
    if coder.target('Rtw')
        coder.cinclude('File_Wrapper.h');
        coder.ceval('function', port, coder.wref(buffer));  
        data = string(char(buffer));
    end
end

I have used the following command to generate code.

codegen -config:lib stepImpl -args {0.0} -launchreport

I hope this helps.