Reading all the words in a text file in C++ - c++

Question

I have a large .txt file and I want to read all of the words inside it and print them on the screen. The first thing I did was to use std::getline() in this way:
std::vector<std::string> words;
std::string line;
while(std::getline(std::cin,line)){
words.push_back(line);
}
and then I printed out all the words present in the vector words. The .txt file is passed from command line as ./a.out < myTxt.txt.
The problem is that each component of the vector is a whole line, and so I am not reading each word.
The problem, I guess, is the spaces between words: how can I tell the code to ignore them? More specifically, is there any function that I can use in order to read each word from a .txt file?
UPDATE:
I'm trying to avoid all the commas ., but also ? ! (). I used find_first_of(), but my program doesn't work. Also, I don't know how to set what are the characters I don't want to be read, i.e. ., ?, !, and so on
std::vector<std::string> my_vec;
std::string line;
while(std::cin>>line){
std::size_t pos = line.find_first_of("!");
std::string line = line.substr(pos);
my_vec.push_back(line);
}

Answer 1

'>>' operator of type string exactly fills your requirements.
std::vector<std::string> words;
std::string line;
while (std::cin >> line) {
words.push_back(line);
}
If you need remove some noisy characters, e.g. ',','.', you can replace them with space character first.
#include <iostream>
#include <sstream>
#include <vector>
#include <algorithm>
int main() {
std::vector<std::string> words;
std::string line;
while (getline(std::cin, line)) {
std::transform(line.begin(), line.end(), line.begin(),
[](char c) { return std::isalnum(c) ? c : ' '; });
std::stringstream linestream(line);
std::string w;
while (linestream >> w) {
std::cout << w << "\n";
words.push_back(w);
}
}
}
cppreference

Answer 2

The getline function, as it sounds, only returns a whole line. You can split each line on spaces after reading it, or you can read word by word using operator>>:
string word;
while (cin >> word){
cout << word << "\n";
words.push_back(word);
}

Answer 3

Use operator>> instead of std::getline(). The operator will read individual whitespace-separated substrings for you.
#include <iostream>
#include <string>
#include <vector>
std::vector<std::string> my_vec;
std::string s;
while (std::cin >> s){
// use s as needed...
}
However, you may still end up receiving strings that have punctuation in them without any surrounding whitespace, ie hello,world, so you will have to manually split those strings as needed, eg:
#include <iostream>
#include <string>
#include <vector>
#include <cctype>
std::vector<std::string> my_vec;
std::string s;
while (std::cin >> s){
std::string::size_type start = 0, pos;
while ((pos = s.find_first_of(".,?!()", start)) != std::string::npos){
my_vec.push_back(s.substr(start, pos-start));
start = s.find_first_not_of(".,?!() \t\f\r\n\v", pos+1);
}
if (start == 0)
my_vec.push_back(s);
else if (start != std::string::npos)
my_vec.push_back(s.substr(start));
}