How to find a specific string in a text file?

How to find a specific string in a text file?
how i did it: i store the whole contents of the .txt file in a single
string, close the file, and then, split the string, based on searching a
specific character: a | bar.

text file test.txt:
helloooooooooo|cool cool|another string|laaaaast one|
the bar "|" is needed to separate words/sentences.

and main.cpp:

 1 #include <iostream>
 2 #include <string>
 3 #include <sstream>
 4 #include <fstream>
 5
 6  int main(){
 7     //load the text file and put it into a single string:
 8     std::ifstream in("test.txt");
 9     std::stringstream buffer;
10     buffer << in.rdbuf();
11     std::string test = buffer.str();
12     std::cout << test << std::endl << std::endl;
13
14     //create variables that will act as "cursors". we‘ll take everything between them.
15     size_t pos1 = 0;
16     size_t pos2;
17
18     //create the array to store the strings.
19     std::string str[4];
20
21     for (int x=0; x<=3; x++){
22         pos2 = test.find("|", pos1); //search for the bar "|". pos2 will be where the bar was found.
23         str[x] = test.substr(pos1, (pos2-pos1)); //make a substring, wich is nothing more
24                                               //than a copy of a fragment of the big string.
25         std::cout << str[x] << std::endl;
26         std::cout << "pos1:" << pos1 << ", pos2:" << pos2 << std::endl;
27         pos1 = pos2+1; // sets pos1 to the next character after pos2.
28                          //so, it can start searching the next bar |.
29     }
30  }

EDIT: and the output:

helloooooooooo|cool cool|another string|laaaaast one|

helloooooooooo
pos1:0, pos2:14
cool cool
pos1:15, pos2:24
another string
pos1:25, pos2:39
laaaaast one
pos1:40, pos2:52

Process returned 0 (0x0)   execution time : 0.047 s
Press any key to continue.

test.find("\\", pos3);

To find a "\" should use "\\".