My code:
void listall() { string line; ifstream input; input.open("registry.txt", ios::in); if(input.is_open()) { while(std::getline(input, line, "\n")) { cout<<line<<"\n"; } } else { cout<<"Error opening file.\n"; } } I’m new to C++, and I want to print out a text file line-by-line. I’m using Code::Blocks.
The error it gives me is:
error: no matching function for call to 'getline(std::ifstream&, std::string&, const char [2])'
These are the valid overloads for std::getline:
istream& getline (istream& is, string& str, char delim); istream& getline (istream&& is, string& str, char delim); istream& getline (istream& is, string& str); istream& getline (istream&& is, string& str); I'm sure you meant std::getline(input, line, '\n')
"\n" is not a character, it's an array of characters with a size of 2 (1 for the '\n' and another for the NUL-terminator '\0').
Write this:
#include <fstream> // for std::ffstream #include <iostream> // for std::cout #include <string> // for std::string and std::getline int main() { std::ifstream input("registry.txt"); for (std::string line; std::getline(input, line); ) { std::cout << line << "\n"; } } If you want the error check, it is something like this:
if (!input) { std::cerr << "Could not open file.\n"; } 
std::cout and the standard error stream which can be written to with std::cerr. It is advisable to write error the std::cerr so that you can distinguish between normal program flow and error messages when running. For example ./a.out > /dev/null will throw away everything written to standard out. ./a.out 2 > errors.txt will write all erorr text to "errors.txt"