B4R Question How to use 2 string vars in inline C++ ?

[peacemaker]

Hi, All

If i need to

• generate string var NewLine = "yyyyMMdd_HHmm;column_0_value;column_1_value;column_2_value;" dynamically, length is variable
• generate string var FileName = "log_yyyyMMdd_HHmm.csv" dynamically, length is fixed
• and pass them both to inline C++ sub (only this way works OK, B4R way does not work). Actually - save this NewLine into a text FileName on an SD-card.

how better to make a code ?

Template is here:

#if C
#include "FS.h"
#include "SD.h"
#include "SPI.h"

void appendFile(fs::FS &fs, const char *path, const char *message) {
  Serial.printf("Appending to file: %s\n", path);

  File file = fs.open(path, FILE_APPEND);
  if (!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if (file.print(message)) {
    Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
  file.close();
}

void save_csv_line(B4R::Object* filename_and_newline_must_be_passed){
    appendFile(SD, "/hello.txt", "World!\n");
}
#End If

Planned to use sub "save_csv_line"

 

[Erel]

You need to do it with two global arrays that are large enough to hold the data.
You can then use ByteConverter.ArrayCopy to copy a local string to the global array of bytes. You will need to first convert it to an array of bytes. Add 0 as the last byte and copy to the global variable.