ifstream::is_open - C++ Reference

http://www.cplusplus.com/reference/fstream/ifstream/is_open/

1 // ifstream::is_open 2 #include 
     
           // std::cout 3 #include 
      
             // std::ifstream 4  5 int main () { 6   std::ifstream ifs ("test.txt"); 7  8   if (ifs.is_open()) { 9     // print file:10     char c = ifs.get();11     while (ifs.good()) {12       std::cout << c;13       c = ifs.get();14     }15   }16   else {17     // show message:18     std::cout << "Error opening file";19   }20 21   return 0;22 }