Question

i have the next code:

  std::string line;
  std::ifstream myfile ("text.txt");
  if (myfile.is_open())
  {
    while ( myfile.good() )
    {
      getline (myfile,line);
      std::cout << line << std::endl;
    }
    myfile.close();
  }

is there a way to do it, and use char* instead of string?

Answer 1

So you’re looking for a more “C-like” solution?

#include<cstdio>
#define ENOUGH 1000

int main() {

    char buffer[ENOUGH];

    FILE* f = fopen("text.txt", "r");
    while (true) {
       if (fgets(buffer, ENOUGH, f) == NULL) break;
       puts(buffer);
    }
    fclose(f);

    return 0;
}

…plus some check whether the file was correctly opened. In this case, you use fgets() on the file f, reading into the char* buffer. However, buffer has only ENOUGH space allocated and this limit is also an important parameter to the fgets() function. It will stop reading the line when reaching ENOUGH - 1 characters, so you should make sure the ENOUGH constant is large enough.

But if you didn’t mean to solve this in a “C-like” way, but are still going to use <iostream>, then you probably just want to know that the c_str() method of std::string returns the char* representation of that std::string.