Print request return from ESP8266 using arduino as bridge

Using Arduino Programming Questions
1

I am trying to achieve something that's probably really simple. I have an ESP8266 module connected to an arduino uno board. The ESP rx and tx are connect to two digital pins in the arduino. I'm also starting serial at 9600 so I can debug it and the esp at 115200, like this:

esp8266.begin(115200);
Serial.begin(9600);

What I did to see if it's working is:

esp8266.println("AT");
if(esp8266.find("OK")){
  Serial.print("It's working!");
}

That's just an example and it worked, I also got positive results when connecting to my wifi printing the proper command to esp8266. So finally, my question is, if I send a GET request, let's say "GET /json", how do I get to display the response from that using Serial.println()? Been stuck in this for quite some time.

2

You could write a function which will get the response from the ESP

eg

void getESP8266Response() {
  while (esp8266.available()) {
    Serial.println(esp8266.readStringUntil('\n')); 
  }
}

That will print out anything that the ESP sends which is terminated by a new line character.

A far better way would be to use the esp8266.available() function to determine if there is a character sent from the ESP, then esp8266.read() to stuff that character into a character array (C style string) until a newline (or some other terminating character) is encountered.
That way you have the string to use later in a serial.print() or any other function you require.
(Not a String.Note the capital 'S' there is a difference between a String and a string. Search this forum and you will read plenty about the evils of using a String.)

Pay a visit to this post, which describes some basic concepts of serial input. Remember that you can treat the ESP as a serial input source while looking through the posts.