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;
Related
I am trying to read a .txt file with some floats into my code.
I wrote a sample code just to tackle the issue outside my main code and I am using the following floats to test it:
10.8f
100.8f
-10.8f
The issue I am running into is that the code only reads in the first float properly and displays it but all the other floats following it do not look correct:
10.8
0
4.57874e-41
Code:
#include<fstream>
#include<iostream>
#include <vector>
#include <string>
#include <iomanip>
using namespace std;
int main()
{
float Cam1,Cam2,Cam3;
string path = "sample.txt"; //Text file with above mentioned floats
ifstream fin;
fin.open(path);
if(fin.is_open())
{
fin >> Cam1;
fin >> Cam2;
fin >> Cam3;
fin.close();
}
cout << Cam1 << '\n';
cout << Cam2 << '\n';
cout << Cam3 << '\n';
}
I really am confused as to why it reads the first properly but not the others, it works when I change the values as well, the above is just one example case. I am fairly new to C++ so any help would be greatly appreciated thank you!
The f suffix is valid in C++ code, but not in input text parsed by istream. It's useful in code to distinguish between float and double constants, but user input doesn't control variable data types.
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);
Here is what I got so far:
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
int characterList = 0;
char* dynamo = new char[1000];
char* buffer = dynamo;
ifstream input("wordlist.txt");
if (input.is_open())
{
input >> dynamo[characterList];
while (input.eof())
{
characterList++;
input >> dynamo[characterList];
cout << dynamo[characterList];
}
}
else
{
cout << "File not opened" << endl;
}
return;
}
I'm a beginner so I do apologize if this looks like terrible coding practice. I created a text file with a quote from Bill Cosby that I'm trying to read one word at a time. The quote is "I don't know the key to success, but the key to failure is trying to please everybody." I'm trying to read one word at a time from a text document ignoring punctuation. I know there are a lot of questions similar to this, but they are using code that I have not learned so I'm sorry for having a repeating question. I have not learned getline (I used cin.getline) and #include <string>.
Edit: I forgot to mention, so I'm sorry for not doing so earlier, but I'm studying dynamic memory allocation which is why I'm using the new char[1000].
I'd suggest you to use std::string instead of manually allocating buffers on the heap with new[] and trying to read text manually from the file into those buffers (and don't forget to free the buffer with proper delete[] calls!).
C++ input stream classes like std::ifstream can simply read text into std::string instances thanks to a proper overload of operator<<.
The syntax is as simple as:
string word;
while (inFile >> word)
{
cout << word << endl;
}
Here's a complete compilable sample code for you to experiment and learn:
#include <fstream>
#include <iostream>
#include <string>
using namespace std;
int main()
{
ifstream inFile("test.txt");
if (inFile.is_open())
{
string word;
while (inFile >> word)
{
cout << word << endl;
}
}
else
{
cout << "Can't open file." << endl;
}
}
This is the output I got on a test text file having the content specified in your question:
I
don't
know
the
key
to
success,
but
the
key
to
failure
is
trying
to
please
everybody.
NOTE
Of course, once you have your words read into a std::string instance, you can store them in a container like std::vector<std::string>, using its push_back() method.
I would do something like this:
#include <iostream>
#include <string>
#include <fstream>
int main() {
std::string array[6];
std::ifstream infile("Team.txt");
std::string line;
int i = 0;
while (std::getline(infile, line)) {
array[i++] = line;
}
return 0;
}
based on this answer.
Here, we assume we have to read 6 lines from the file "Team.txt". We use std:::getline() and we put inside a while so that we read all the file.
At every iteration, line holds the current line of the file read. Inside the body we store it in array[i].
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.
I am working on a small program that takes a input file and processors the data in the file. With my current code (see below) when you enter a valid file name it just freezes the command line (drops down a line and just shows a flashing _ ) and I have to kill the program to get out. If you enter a invalid file name the if(!file) gets called and runs fine.
Whats really odd is that if I put a debugging cout above that if statement it will not get called if the file name is correct. Hope you can help and if you need more info let me know!
This is my current code:
using namespace std;
#include <iostream>
#include <stdexcept>
#include <string>
#include <fstream>
#include <vector>
#include <cctype>
#include "Student.h"
int main(){
string filename, name;
char *inputfile;
ifstream file;
vector<Student> students;
const int SIZE = 200;
char buffer [SIZE];
int regno, i;
cout << "Enter file name: ";
cin >> filename;
inputfile = const_cast<char*> (filename.c_str());
file.open(inputfile);
if (!file){
cout << "Failed to open " << filename << endl;
exit(1);
}
while (!file.eof()){
file.getline(buffer, SIZE);
i = 0;
regno = 0;
while (isdigit(buffer[i])){
regno = (regno*10)+buffer[i];
}
cout << regno;
}
file.close();
}
Your problems is that you never increase i in the cycle.
Here:
i = 0;
regno = 0;
while (isdigit(buffer[i])){
regno = (regno*10)+buffer[i];
}
You go into infinite cycle as i always stays 0.
Also why do you do the const_cast? You can open using a const char * too. So you can write this:
cin >> filename;
file.open(filename.c_str());
And code will still work.
There's another problem in your code concerning the use of getline() and eof(). The idiomatic way to read a file line-by-line is this:
std::string line;
while(getline(in, line)) {
// handle line here
}
in refers to some input stream like a std::ifstream or std::cin. The point is that reading a line can fail (e.g. due to EOF), which you check in above loop. Your version only checks if EOF was encountered before but not that the subsequent getline() call actually yielded any data.