File won't open, I don't know why - c++

Question

My FILE WONT OPEN HELP
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main()
{
string input_file_name, output_file_name; //file names
ifstream infile; //input file object
ofstream outfile; //output file object
//prompt user for input file
cout << "Enter the input file name: ";
cin >> input_file_name;
//open input file
infile.open(input_file_name.c_str());
//check if file opened successfully
if (!infile)
{
cout << "Error: Unable to open file" << endl;
cout << "Terminating program...";
return 1;
}
else
{
cout << "Successfully opened file!";
}
return 0;
}
when asked for user input i type filename.txt and it wont display successfuly opened message? why....i have the filename.txt on my pc

Answer 1

First off, pardon my use of 'goto', I just felt like it... Try something like what I have shown below where I check if the file actually opened (save the code stub as "asdf.cpp"). Of course you will have to read the data into an array, but it may be a good place to start.
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main(int argc, char * argv[])
{
string line;
ifstream f("asdf.cpp");
if ( !f.is_open() )
goto error_file_not_open;
while( getline(f, line) )
cout << line << endl;
f.close();
return 0;
error_file_not_open:
cout << "Could not open file" << endl;
return -1;
}

Answer 2

If you want to save and read values from/to file, then try something like this:
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main()
{
// Write values to a file
const int size = 5;
int values[] = { 1,2,3,4,5,6 };
ofstream myfile("lol.txt");
if (myfile.is_open())
{
for (int count = 0; count < size; count++) {
myfile << values[count] << endl;
}
myfile.close();
}
else {
cout << "Unable to open file";
}
// Write read values from a file
std::ifstream file("lol.txt");
if (file.is_open()) {
std::string line;
while (getline(file, line)) {
cout << line.c_str() << endl;
}
file.close();
}
else {
cout << "Unable to open file";
}
}

Answer 3

I'am afraid that your file is not an ANSI-ASCII encoded text file. May be it is encoded by UTF-8 or the Unicode format. The following code will check that the encode of your file. Just try to run it or you could open the lol.txt by any text editor such as, vscode or notepad++.
It will show the encode format of the file at the right-down corner.
Another way to prevent from this issue is try to save the text file to the ANSC-ASCII format. Hope this will help! ^_^
#include <iostream>
#include <fstream>
using namespace std;
unsigned char UTF8Header[] = {0xef, 0xbb, 0xbf};
unsigned char UNICODEHeader[] = {0xff, 0xfe};
int main()
{
char fileName[] = "lol.txt"; // replace the file with your actual file name.
std::ifstream in;
char buffer[3] = {0};
in.open(fileName, std::ios::in | std::ios::binary);
if (!in.is_open())
{
std::cout << "Error opening file";
return -1;
}
if (!in.eof())
in.read(buffer, 2);
if (!in.eof())
in.read(buffer + 2, 1);
if (buffer[0] == UNICODEHeader[0] && buffer[1] == UNICODEHeader[1])
cout << "The file is encoded by unicode format" << endl;
else if (buffer[0] == UTF8Header[0] && buffer[1] == UTF8Header[1] && buffer[2] == UTF8Header[2])
cout << "The file is encoded by UTF-8 format" << endl;
return 0;
}