how to open a file by its full path given by user? - c++

I have written this code. I want to ask from user the full path of a file and then go to that path and open file. But unfortunately the program cannot find the file. for excample I have created a file in this path G:\project 2\newfile but when I type this in the c++ console it says that "Error while opening the file". I really need to solve this problem. please help me with this. thanks
#include <iostream>
#include <fstream>
#include <conio.h>
#include <windows.h>
using namespace std;
int main()
{
string address;
cout << "Enter the full path of the file" << endl;
cin >> address;
ifstream file(address.c_str());
if (!file) {
cout << "Error while opening the file" << endl;
return 1;
}
return 0;
}

Your application is failing because you aren't properly handling spaces in the filename.
Try this instead of cin >> address;:
getline(cin,address);
See this question for the difference between cin and getline.

Related

ifstream says it opened a file but the file doesnt open

I am using visual studio 2017
I am new to c++ and here I tried to open a txt file, and confirming that it was opened.
#include <iostream>
#include <fstream>
#include <String>
using namespace std;
int main()
{
ifstream infile;
string text;
infile.open("C:\\Users\\gab_a\\source\\repos\\one\\testing.txt");
if (!infile.is_open()) {
cerr << "Specified file could not be found ";
exit(1);
}
else {
cout << "Opened file ";
infile >> text;
cout << text;
}
return 0;
}
it says that it opened it, and it even read the text that was inside the file, but the actual file isn't opening, I even put the file in the same directory as the project. There are also no errors, so why isn't my file opening?
What you're doing is reading the data from the file into a stream. This is not the same as executing a program to open the file. To do that is generally OS specific, but if you're on Windows you can use ShellExecute or CreateProcess. I do suggest you brush up on your C++ a bit - no offense intended

Ifstream cannot open file with amdinistrator rights

I used this code to try to open and read the file (not empty), but ifstream did not work - it could not open the file: I addded the check on file opening and it showed, that ifstream even did not (could not) open the file.
I gave administrator rights to the program, but ifstream still could not read the file.
I also tried to find a path, where ifstream would read this file, but I did not success, and at last I tried to open file using the absolute path - but result is the same.
The file is situated in the root folder of the program, but I placed it everywhere and nothing changed.
#include <iostream>
#include <string>
#include <fstream>
using namespace std;
int main() {
string s;
ifstream file("fix.txt");
if (file)
cout << "SUCCESSFULL OPENING" << endl;
while (getline(file, s)) {
cout << s << endl;
s += "+";
cout << s << endl;
}
file.close();
return 0;
}
You may have access to a more detailed error code by activating exceptions on the stream via
file.exceptions(std::ios_base::failbit);
Then, you get more details by writing
try {
file.open("fix.txt");
}
catch(std::ios_base::failure& f) {
// f.what() contains a message, f.code() returns a std::error_code
}

Why isn't my input stream opening my file? C++

I'm reading in a file name from the keyboard and opening the specified file. However it is not meeting my if statement that determines if it's open or not. Heres my code:
#include "prog.hh"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
string fileName;
cout << "Enter the file name to be read: ";
cin >> fileName;
ifstream input_file("fileName");
std::string line_; // string which text file contents will be stored in
if(input_file.is_open()){ // validation to see if the file is open
while(getline(input_file, line_)){
std::cout<<line_<< '\n'; //prints the contents of the file into the console
}
input_file.close();
}
else {
std::cout<<"File is not open"<< '\n';
}
std::cin.get();
After being compiled, I type in the file name I want to open and I get back the else message "File is not open", although the ifstream should of opened it. I definitely have the right file I'm trying to open in the correct folder. Any help appreciated, thanks.
change
ifstream input_file("fileName");
to
ifstream input_file(fileName);

Creating and writing a file C++

I have made a scripting language and I was writing a program which would 1: Ask for your path to read the script and 2: Compile the code into a custom Hexadecimal which would be read by another program to do the hard work for me. My problem is I cannot create a new file and write the custom hexadecimal code onto that file.
Here is an example of my code:
#include <iostream>
#include <string>
#include <Windows.h>
#include <wincon.h>
#include <fstream>;
using namespace std;
int main(){
string path;
string title;
cout << "Enter your path to compile your *.egSCRIPT file: ";
cin >> path;
cout << "Enter the title for the new file";
cin >> title;
ofstream myfile(path+"\\"+title+".myScriptLanguage");
myfile.open(path);
myfile << "IT WORKS!!!";
myfile.close();
return 0;
}
I want it to make a new .whatevertheheckyouwanttocallit file and write onto the file IT WORKS!!! just as a sample. I will eventually write onto it a custom hexadecimal system of code to be read by my interpreter. Thanks in advance.
ofstream myfile;
myfile.open(path+"\\"+title+".myScriptLanguage");
myfile << "IT WORKS!!!";
myfile.close();
Try the above;

C++ ifstream will not open any files

Whenever I try to open a file with ifstream, it compiles fine, but will not open the file.
The file in this example doesn't exist, but ifstream *s*should*s* create the file for me.
i have some example code that i think should work, but does not open or create the file
"foo.txt". Is there something that i'm missing, or is my IDE just messed up?
i'm using visual studio 2008 VC++ , btw
thanks
here's the code:
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main(){
ifstream in;
string hold;
in.open("foo.txt",ios::in);
if(!in){
cerr << "Couldn't open file!" << endl;
}
in >> hold;
cout << hold << endl;
system("pause");
return 0;
}
The problem is you are using an in stream instead of an out stream, as Adam Liss mentioned(ios::out rather than ios::in). You also need to make sure you close the file before return 0; to make sure everything from the buffer is actually written to the file.
The open function will not create files in ios::in mode; you need to use ios::out.