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Quine Program

Aug 9, 2013 at 5:38pm
Bad Wolf Virus (1)
I read about quines on Wikipedia and thought they were kind of interesting. I made a program and I wanted to know if it is considered a quine.

#include <fstream>
#include <windows.h>
using namespace std;
int main()
{
system("@echo off");
ofstream a_file("example.cpp");
a_file << "#include <fstream>\n";
a_file << "#include <windows.h>\n";
a_file << "using namespace std;\n";
a_file << "int main()\n";
a_file << "{\n";
a_file << "\tsystem(\"@echo off\");\n";
a_file << "\tofstream a_file(\"example2.cpp\");\n";
a_file << "\ta_file << \"#include <fstream>\\n\";\n";
a_file << "\ta_file << \"#include <windows.h>\\n\";\n";
a_file << "\ta_file << \"using namespace std;\\n\";\n";
a_file << "\ta_file << \"int main()\\n\";\n";
a_file << "\ta_file << \"{\\n\";\n";
a_file << "\ta_file << \"\tsystem(\\\"@echo off\\\");\\n\";\n";
a_file << "\ta_file << \"\tofstream a_file(\\\"example2.cpp\\\");\\n\";\n";
a_file << "\ta_file << \"\tsystem(\\\"pause\\\");\\n\";\n";
a_file << "\ta_file << \"\treturn 0;\\n\";\n";
a_file << "\ta_file << \"}\";\n";
a_file << "\tsystem(\"pause\");\n";
a_file << "\treturn 0;\n";
a_file << "}";
system("pause");
return 0;
}

>>>>>>>>>>>>>>> example.cpp <<<<<<<<<<<<<<<
#include <fstream>
#include <windows.h>
using namespace std;
int main()
{
system("@echo off");
ofstream a_file("example2.cpp");
a_file << "#include <fstream>\n";
a_file << "#include <windows.h>\n";
a_file << "using namespace std;\n";
a_file << "int main()\n";
a_file << "{\n";
a_file << " system(\"@echo off\");\n";
a_file << " ofstream a_file(\"example2.cpp\");\n";
a_file << " system(\"pause\");\n";
a_file << " return 0;\n";
a_file << "}";
system("pause");
return 0;
}

>>>>>>>>>>>>>>> example2.cpp <<<<<<<<<<<<<<<
#include <fstream>
#include <windows.h>
using namespace std;
int main()
{
system("@echo off");
ofstream a_file("example2.cpp");
system("pause");
return 0;
}

Also, since quines print the source code of the program, how do viruses replicate themselves if they are already compiled?
Aug 9, 2013 at 6:02pm
fafner (377)
I'm not entirely sure what you're asking, finding out if a program is a quine is just a matter of running it and checking :P
Last edited on Aug 9, 2013 at 6:02pm
Aug 9, 2013 at 6:17pm
closed account (Dy7SLyTq)
why not just have it open itsself and read every file of the line?
Aug 9, 2013 at 9:50pm
ResidentBiscuit (4459)
why not just have it open itself and read every file of the line?

Because then it's not a quine. A quine can't take any form of input.
Aug 9, 2013 at 10:00pm
andywestken (4088)
I made a program and I wanted to know if it is considered a quine.

No. The source you're writing out is not the same as the original source.

how do viruses replicate themselves if they are already compiled?

Viruses replicate at the machine code level; they add new code to the host program and modify the existing code to reroute calls to their own proceedures.

Andy
Last edited on Aug 9, 2013 at 10:08pm
Aug 10, 2013 at 6:14am
JLBorges (13770)
With the advent of raw string literals, it's easy to write quite readable quines.

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#include <iostream>
#include <string>

const std::string text = R"quine(
        const std::string prefix = "#include <iostream>\n"
                                   "#include <string>\n\n"
                                   "const std::string text = R\"quine(" ;
        const std::string suffix = ")quine\";\n\n";
        const std::string quine = prefix + text + suffix + text ;
            //         _
            //        / )
            //       / /
            //      / /               /)
            //     / /     .-```-.   / ^`-.
            //     \ \    /       \_/  (|) `o
            //      \ \  /   .-.   \\ _  ,--'
            //       \ \/   /   )   \( `^^^
            //        \   \/    (    )
            //         \   )     )  /
            //          ) /__    | (__
            //         (___)))   (__)))
            //
        int main() { std::cout << quine ; }

)quine";


        const std::string prefix = "#include <iostream>\n"
                                   "#include <string>\n\n"
                                   "const std::string text = R\"quine(" ;
        const std::string suffix = ")quine\";\n\n";
        const std::string quine = prefix + text + suffix + text ;
            //         _
            //        / )
            //       / /
            //      / /               /)
            //     / /     .-```-.   / ^`-.
            //     \ \    /       \_/  (|) `o
            //      \ \  /   .-.   \\ _  ,--'
            //       \ \/   /   )   \( `^^^
            //        \   \/    (    )
            //         \   )     )  /
            //          ) /__    | (__
            //         (___)))   (__)))
            //
        int main() { std::cout << quine ; }
Edit & run on cpp.sh

http://ideone.com/4PULUU
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