Esp32 read lines from text file as strings get wrong worder - c++

Question

I have a text file test1.txt:
aaa|aaa|aaa
bbb|bbb|bbb
ccc|ccc|ccc
ddd|ddd|ddd
File has 4 rows as you can see. I use this code to read the content of the file and get each line as a separated string:
#include "SPIFFS.h"
String file_content = "";
char VALUE [1024] = {'\0'};
void setup() {
Serial.begin(9600);
if (!SPIFFS.begin(true)) {
Serial.println("An Error has occurred while mounting SPIFFS");
return;
}
File file = SPIFFS.open("/test1.txt");
if (!file) {
Serial.println("Failed to open file for reading");
return;
}
uint16_t i = 0;
while (file.available()) {
VALUE[i] = file.read();
Serial.println (VALUE[i]);
i++;
}
VALUE[i] ='\0';
Serial.println("Raw print");
Serial.println (VALUE); //use for debug
Serial.println("String print");
String myString = String(VALUE);
Serial.println (myString);
file.close();
int delimiter, delimiter_1, delimiter_2, delimiter_3, delimiter_4;
delimiter = myString.indexOf("\n");
delimiter_1 = myString.indexOf("\n", delimiter + 1);
delimiter_2 = myString.indexOf("\n", delimiter_1 +1);
delimiter_3 = myString.indexOf("\n", delimiter_2 +1);
delimiter_4 = myString.indexOf("\n", delimiter_3 +1);
// Define variables to be executed on the code later by collecting information from the readString as substrings.
String row1 = myString.substring(delimiter + 1, delimiter_1);
String row2 = myString.substring(delimiter_1 + 1, delimiter_2);
String row3 = myString.substring(delimiter_2 + 1, delimiter_3);
String row4 = myString.substring(delimiter_3 + 1, delimiter_4);
Serial.println("Rows print");
Serial.println(row1);
Serial.println(row2);
Serial.println(row3);
Serial.println(row4);
}
void loop() {}
Output of Rows print is:
Rows print
bbb|bbb|bbb
ccc|ccc|ccc
ddd|ddd|ddd
aaa|aaa|aaa
Why is the "aaa" row thelast one and not first one? Basically delimiter_1 is "bbb" row instead be "aaa" row, and delimiter_4 is "aaa" row instead "ddd" row.
Thanks.

Answer 1

Try this:
#include <SPIFFS.h>
using namespace std;
void setup() {
Serial.begin(115200);
if (!SPIFFS.begin(true)) {
Serial.println("An Error has occurred while mounting SPIFFS");
return;
}
File file = SPIFFS.open("/test1.txt");
if (!file) {
Serial.println("Failed to open file for reading");
return;
}
vector<String> v;
while (file.available()) {
v.push_back(file.readStringUntil('\n'));
}
file.close();
for (String s : v) {
Serial.println(s);
}
}
void loop() {}
Output:
aaa|aaa|aaa
bbb|bbb|bbb
ccc|ccc|ccc
ddd|ddd|ddd
EDIT:
If you want to manipulate individual element, you could use regular for-loop iteration. See example below:
for (int i = 0; i < v.size(); i++){
Serial.println(v[i]);
}