find pattern 'answer="$1"', print all $1 out

extract_chars.cpp

#include <stdlib.h> 

int main() { 
  system("cat text.txt | grep -Po 'answer=\"\\K[^\"]*'"); 
  return 0; 
}

extract_chars.sh

#!/bin/bash

cat text.txt | grep -Po 'answer="\K[^"]*'

text.txt

<div class="row">
<div class="span10">
<p>Remember, the <strong>only thing</strong> before everything, is to have a dogma. A dogma is a list consists by DOs and DONTanswer="C"s. You make it, stick to it while adapt it to reality, question yourself from time to time: is everything on the list mutuallanswer="A"y exclanswer="B"usive and collectively eanswer="B"xanswer="C"hausive?</p>

<p>And there is a meta dogma for dogmas:</p>

<ul>
<li>Avoid emotional tactics</li>
<li>Every kindness counts</li>
<li>Gentleness is the ultimate strength</li>
</ul>