Writing persian ( farsi ) by class wfstream in output file - c++

How can I write Persian text like "خلیج فارس" to a file using a std::wfstream?
I tried following code but it does not work.
#include <iostream>
#include <string>
#include <fstream>
int main()
{
std::wfstream f("D:\\test.txt", std::ios::out);
std::wstring s1(L"خلیج فارس");
f << s1.c_str();
f.close();
return 0;
}
The file is empty after running the program.

You can use a C++11 utf-8 string literal and standard fstream and string:
#include <iostream>
#include <fstream>
int main()
{
std::fstream f("D:\\test.txt", std::ios::out);
std::string s1(u8"خلیج فارس");
f << s1;
f.close();
return 0;
}

First of all you can left
f << s1.c_str();
Just use
f << s1;
To write "خلیج فارس" with std::wstream you must specify imbue for persian locale like:
f.imbue(std::locale("fa_IR"));
before you write to file.

Related

In C++, opening a csv file with ifstream

I am trying to open a csv file in C++ using ifstream with a directory in the file path name. The file does reside in the specified directory location, but I observe an for the variable inFile when executing the code. My research up to this point says the code is correct, but something obviously is wrong. Any suggestions?
Thanks,
KG
#include <string>
#include <fstream>
#include <iostream>
virtual void run()
{
string file_dir = "/home/datafiles/";
string csvFile = file_dir + "/myFile.csv";
ifstream inFile;
inFile.open("csvFile", ios::in);
// file check to see if file is open
if(!inFile.is_open()) {
cout << "error while opening the file" << endl;
}
}
I found the answer to my csv file opening problem, a colleague assisted.
#David - You suggested removing the double quotes in the "inFile.open" line of code. In addition to removing the double quotes, I also needed to add c_str(), which "returns a pointer to a null-terminated character array with data equivalent to those stored in the string," .data() also performs the same function (cppreference.com).
#user4581301 - I am also aware that ios::in is implied with a ifstream, only included it here as a reference; thanks.
The modified code is listed below:
#include <string>
#include <fstream>
#include <iostream>
virtual void run()
{
string file_dir = "/home/datafiles/";
string csvFile = file_dir + "/myFile.csv";
ifstream inFile;
inFile.open(csvFile.c_str(), ios::in);
// file check to see if file is open
if(!inFile.is_open()) {
cout << "error while opening the file" << endl;
}
}
Really appreciate all the help.
Enjoy,
KG
Is this what you're trying to do?
#include <iostream> // std::{ cout, endl }
#include <string> // std::{ string, getline }
#include <fstream> // std::ifstream
auto main() -> int {
// Just to demonstrate.
// You want to use your real path instead of example.cpp
auto file = std::ifstream("example.cpp");
auto line = std::string();
while ( std::getline(file, line) )
std::cout << line << '\n';
std::endl(std::cout);
}
Live example

strange behaviour of procmail when piping content to c++ executable

I have a working procmail config.
this is the rc.filters :
:0 w :a.lock
* ^From:(.*\<)?(try#gmail\.com)\>
| $HOME/executable/a.out
this file compiles and works, procmail delivers the mail,
and the executable writes the content to the output file.
#include <stdlib.h>
#include <iostream>
#include <fstream>
using namespace std;
int main(void)
{
ofstream myfile;
myfile.open ("output.txt");
string line;
while (getline(cin, line))
{
myfile << line << endl;
}
myfile.close();
return EXIT_SUCCESS;
}
the problem is I need a cin object with the content to pass
to a constructor of the Mimetic library.
I need this executable to work:
#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <mimetic/mimetic.h>
using namespace std;
using namespace mimetic;
int main(void)
{
ofstream myfile;
myfile.open ("output.txt");
MimeEntity me(cin);
const Header& h = me.header();
string subjectString = h.subject();
myfile << subjectString;
myfile << "Check";
myfile.close();
return EXIT_SUCCESS;
}
If I take a Mime message called message.txt and do the following with the second code :
cat message.txt | ./a.out
./a.out < message.txt
In both cases the executable works and I get the subject in an output.txt
but for some when it is invoked and the content piped by procmail it doesn't work,
and all I get in the output.txt is "Check" which means that the file
was at least invoked.
the procmail.log states that everything is fine.
I don't know what's going on exactly but I would capture the input from std::cin into a string and then pass a std::istringstream constructed from that value to MimeEntity. This way you can inspect what the input from std::cin was while still having it processed by the library:
std::istreambuf_iterator<char> begin(std::cin), end;
std::string message(begin, end);
out << "received >>>" << message << "<<<\n";
std::istringstream in(message);
MimeEntity me(in);
// ...

Reading a file to a string in C++

As somebody who is new to C++ and coming from a python background, I am trying to translate the code below to C++
f = open('transit_test.py')
s = f.read()
What is the shortest C++ idiom to do something like this?
The C++ STL way to do this is this:
#include <string>
#include <iterator>
#include <fstream>
using namespace std;
wifstream f(L"transit_test.py");
wstring s(istreambuf_iterator<wchar_t>(f), (istreambuf_iterator<wchar_t>()) );
I'm pretty sure I've posted this before, but it's sufficiently short it's probably not worth finding the previous answer:
std::ifstream in("transit_test.py");
std::stringstream buffer;
buffer << in.rdbuf();
Now buffer.str() is an std::string holding the contents of transit_test.py.
You can do file read in C++ as like,
#include <iostream>
#include <fstream>
#include <string>
int main ()
{
string line;
ifstream in("transit_test.py"); //open file handler
if(in.is_open()) //check if file open
{
while (!in.eof() ) //until the end of file
{
getline(in,line); //read each line
// do something with the line
}
in.close(); //close file handler
}
else
{
cout << "Can not open file" << endl;
}
return 0;
}

How create file in C++ in a specific place in the PC

Hey all, I have a problem, I don't know how to create a file in C++ in a specific place in the PC. For example a file (.txt) in C:\file.txt. Can anybody help me? Thank you :)
#include <iostream>
#include <fstream>
using namespace std;
int main() {
ofstream ofs("c:\\file.txt");
if (ofs) {
ofs << "hello, world!\n";
}
return 0;
}
It's probably fooling you because it's easier than you think. You just open a file for create and give it that path name. Voila.
See, eg,
// fstream::open
#include <fstream>
using namespace std;
int main () {
fstream filestr;
// You need a doubled backslash in a C string
filestr.open ("C:\\file.txt", fstream::out);
// >> i/o operations here <<
filestr.close();
return 0;
}
#include <stdio.h>
....
FILE *file;
file = fopen("c:/file.txt", "w");

Creating files in C++

I want to create a file using C++, but I have no idea how to do it. For example I want to create a text file named Hello.txt.
Can anyone help me?
One way to do this is to create an instance of the ofstream class, and use it to write to your file. Here's a link to a website that has some example code, and some more information about the standard tools available with most implementations of C++:
ofstream reference
For completeness, here's some example code:
// using ofstream constructors.
#include <iostream>
#include <fstream>
std::ofstream outfile ("test.txt");
outfile << "my text here!" << std::endl;
outfile.close();
You want to use std::endl to end your lines. An alternative is using '\n' character. These two things are different, std::endl flushes the buffer and writes your output immediately while '\n' allows the outfile to put all of your output into a buffer and maybe write it later.
Do this with a file stream. When a std::ofstream is closed, the file is created. I prefer the following code, because the OP only asks to create a file, not to write in it:
#include <fstream>
int main()
{
std::ofstream { "Hello.txt" };
// Hello.txt has been created here
}
The stream is destroyed right after its creation, so the stream is closed inside the destructor and thus the file is created.
#include <iostream>
#include <fstream>
int main() {
std::ofstream o("Hello.txt");
o << "Hello, World\n" << std::endl;
return 0;
}
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
string filename = "/tmp/filename.txt";
int main() {
std::ofstream o(filename.c_str());
o << "Hello, World\n" << std::endl;
return 0;
}
This is what I had to do in order to use a variable for the filename instead of a regular string.
Here is my solution:
#include <fstream>
int main()
{
std::ofstream ("Hello.txt");
return 0;
}
File (Hello.txt) is created even without ofstream name, and this is the difference from Mr. Boiethios answer.
If you want to create a file with some content and don't need to deal with the ofstream after that you can simply write:
#include <fstream>
int main() {
std::ofstream("file.txt") << "file content";
}
no need to manually close the file, deal with variables, etc. The file is created, written, and closed in the same line.
/*I am working with turbo c++ compiler so namespace std is not used by me.Also i am familiar with turbo.*/
#include<iostream.h>
#include<iomanip.h>
#include<conio.h>
#include<fstream.h> //required while dealing with files
void main ()
{
clrscr();
ofstream fout; //object created **fout**
fout.open("your desired file name + extension");
fout<<"contents to be written inside the file"<<endl;
fout.close();
getch();
}
After running the program the file will be created inside the bin folder in your compiler folder itself.
use c methods FILE *fp =fopen("filename","mode");
fclose(fp);
mode means a for appending
r for reading ,w for writing
/ / using ofstream constructors.
#include <iostream>
#include <fstream>
std::string input="some text to write"
std::ofstream outfile ("test.txt");
outfile <<input << std::endl;
outfile.close();