遇到换行符时，getline崩溃

Question

I am trying to read in some informations from txt file with \\n endings. However whenever I come a cross an empty line, I get a seg fault. However I just want the line to get ignored.

code:

std::ifstream config_file (config_);
string input_line;

while (std::getline(config_file, input_line))
  {
    if (??check for newline??)
      continue   
  }

I tried so far: changing getline to these parameters:

    (config_file, input_line, '\n')

and this if statement:

if (input_line.at(0) == '\n')

However I always get seg faults ^^'.

Answer 1

Use of

if (input_line.at(0) == '\n')

to check whether is an empty line is wrong sincce std::getline reads and discards the delimiter ( '\\n' in your case).

Instead, use

if (input_line.empty())

Answer 2

std::getline will discard the newline. You can check for std::string::empty() to detect an empty line.