#include <iostream>
#include <fstream>
#include <string>
#include <cctype>
#include <vector>

using namespace std;

void readFile(string);

class info {
    public:

    int rows;
    int cols;
    vector < string > data;
};

int main(int argc, char **argv){

    string filename1;
    filename = argv[1];
    readFile(filename);

    return 0;
}

//should read onle line at a time from a file and print it
void readFile(string filename1){
    fstream datafile;
    datafile.open(filename1);

    while (!datafile.eof()){
            string line;
            getline(datafile,line);
            cout<<line<<endl;
    }

    datafile.close();
}

project2.cpp: In function ‘int main(int, char**)’:
project2.cpp:22:2: error: ‘filename’ was not declared in this scope
  filename = argv[1];
  ^
project2.cpp: In function ‘void readFile(std::string)’:
project2.cpp:32:25: error: no matching function for call to     ‘std::basic_fstream<char>::open(std::string&)’
  datafile.open(filename1);
                     ^
project2.cpp:32:25: note: candidate is:
In file included from project2.cpp:2:0:
/usr/lib/gcc/x86_64-pc-cygwin/4.9.3/include/c++/fstream:889:7: note: void     std::basic_fstream<_CharT, _Traits>::open(const char*, std::ios_base::openmode)     [with _CharT = char; _Traits = std::char_traits<char>; std::ios_base::openmode =     std::_Ios_Openmode]
       open(const char* __s,
       ^
/usr/lib/gcc/x86_64-pc-cygwin/4.9.3/include/c++/fstream:889:7: note:   no     known conversion for argument 1 from ‘std::string {aka std::basic_string<char>}’     to ‘const char*’