Matlab Coder with Command Line Parameters

I have completed the coderand example. My next step is to create an executable that accepts command line inputs.

Here is my MATLAB code:

function c = Calculator(whichcalc) %#codegen
fprintf('%s\n',whichcalc);
if whichcalc=="pressure"
    c = "Your calc is the pressure calculator";
elseif whichcalc=="temperature"
    c = "Your calc is the temperature calculator";
else
    c = "No idea which calculator.";
end
fprintf('%s\n',c);
end

And the associated command to run the application:

I've created the C++ source code using Matlab coder & then used Visual Studio to compile the code using a local ubuntu vm.

Where have I gone wrong?

[Ryan Livingston]

Can you share the C++ main function that you're using? The generated code doesn't read from the command line, so your main function needs to take argv and forward that to the generated entry-point function.

Here's an example that shows taking arguments in the main function and passing them to the generated code:

https://www.mathworks.com/help/coder/ug/generate-and-modify-an-example-cc-main-function.html#buod55s

Specifically look at main in main.c that reads from argv.

[Kristen Lancaster]

Thank you very much for the example. That looks like it will help tremendously.

I did finally get things working. I'll post here in case you have some suggestions or in case others benefit from my hard-earned gains.

Proof:

Code (main.cpp):

static void main_Calculator(string whichcalc)
{
  /* Initialize function 'Calculator' input arguments. */
  /* Initialize function input argument 'whichcalc'. */
  /* Call the entry-point 'Calculator'. */
  Calculator(whichcalc);
}

int main(int argc, char *argv[])
{
  /* Initialize the application.
     You do not need to do this more than one time. */
  Calculator_initialize();

  /* Invoke the entry-point functions.
     You can call entry-point functions multiple times. */
  main_Calculator(argv[1]);

  /* Terminate the application.
     You do not need to do this more than one time. */
  Calculator_terminate();
  return 0;
}

Code (Calculator.cpp):

void Calculator(string whichcalc)
{
  int minSize;
  int i;
  cell_wrap_0 validatedHoleFilling[1];
  bool equal;
  char varargin_1_data[40];
  static const char cv0[8] = { 'p', 'r', 'e', 's', 's', 'u', 'r', 'e' };

  char c_Value_data[39];
  static const char cv1[36] = { 'Y', 'o', 'u', 'r', ' ', 'c', 'a', 'l', 'c', ' ',
    'i', 's', ' ', 't', 'h', 'e', ' ', 'p', 'r', 'e', 's', 's', 'u', 'r', 'e',
    ' ', 'c', 'a', 'l', 'c', 'u', 'l', 'a', 't', 'o', 'r' };

  static const char cv2[11] = { 't', 'e', 'm', 'p', 'e', 'r', 'a', 't', 'u', 'r',
    'e' };

  static const char cv3[25] = { 'N', 'o', ' ', 'i', 'd', 'e', 'a', ' ', 'w', 'h',
    'i', 'c', 'h', ' ', 'c', 'a', 'l', 'c', 'u', 'l', 'a', 't', 'o', 'r', '.' };

  static const char cv4[39] = { 'Y', 'o', 'u', 'r', ' ', 'c', 'a', 'l', 'c', ' ',
    'i', 's', ' ', 't', 'h', 'e', ' ', 't', 'e', 'm', 'p', 'e', 'r', 'a', 't',
    'u', 'r', 'e', ' ', 'c', 'a', 'l', 'c', 'u', 'l', 'a', 't', 'o', 'r' };

  if (whichcalc.length() != 0) {
    minSize = whichcalc.length();
    for (i = 0; i < minSize; i++) {
      validatedHoleFilling[0].f1.data[i] = whichcalc[i];
    }

    validatedHoleFilling[0].f1.data[whichcalc.length()] = '\x00';
    minSize = whichcalc.length() + 1;
    for (i = 0; i < minSize; i++) {
      varargin_1_data[i] = validatedHoleFilling[0].f1.data[i];
    }

    printf("%s\n", &varargin_1_data[0]);
    fflush(stdout);
  }

  /* fprintf('%s\n',whichcalc); */
  minSize = whichcalc.length();
  if (minSize >= 8) {
    minSize = 8;
  }

  if (minSize == 0) {
    equal = (whichcalc.length() == 8);
  } else {
    i = 0;
    while ((i + 1 <= minSize) && (!(whichcalc[i] != cv0[i]))) {
      i++;
    }

    if (i + 1 == minSize + 1) {
      equal = (whichcalc.length() == 8);
    } else {
      equal = (whichcalc[i] == cv0[i]);
    }
  }

  if (equal) {
    minSize = 36;
    for (i = 0; i < 36; i++) {
      c_Value_data[i] = cv1[i];
    }
  } else {
    minSize = whichcalc.length();
    if (minSize >= 11) {
      minSize = 11;
    }

    if (minSize == 0) {
      equal = (whichcalc.length() == 11);
    } else {
      i = 0;
      while ((i + 1 <= minSize) && (!(whichcalc[i] != cv2[i]))) {
        i++;
      }

      if (i + 1 == minSize + 1) {
        equal = (whichcalc.length() == 11);
      } else {
        equal = (whichcalc[i] == cv2[i]);
      }
    }

    if (equal) {
      minSize = 39;
      for (i = 0; i < 39; i++) {
        c_Value_data[i] = cv4[i];
      }
    } else {
      minSize = 25;
      for (i = 0; i < 25; i++) {
        c_Value_data[i] = cv3[i];
      }
    }
  }

  for (i = 0; i < minSize; i++) {
    validatedHoleFilling[0].f1.data[i] = c_Value_data[i];
  }

  validatedHoleFilling[0].f1.data[minSize] = '\x00';
  minSize++;
  for (i = 0; i < minSize; i++) {
    varargin_1_data[i] = validatedHoleFilling[0].f1.data[i];
  }

  printf("%s\n", &varargin_1_data[0]);
  fflush(stdout);
}

Modifications necessary:

• Accept arguments in main
• Pass argument to main_calculator
• Update main_calculator to accept string (it was previously accepting a custom-made data type that MATLAB Coder generated)
• Update Calculator to use strings using the typical length() function and string indexing ([i])
• Update function definitions in related .h files