how to add variable to string??!

Hi,
am editing this C++ code..
It will get the folder directory.. then i want to copy a file to sub folder in that directory.

Code:

#include <fstream>
#include <string>
#include <iostream>
using namespace std;

bool copyFile (const char SRC[], const char DEST[])
{
    std::ifstream src; // the source file
    std::ofstream dest; // the destination file

    src.open (SRC, std::ios::binary); // open in binary to prevent jargon at the end of the buffer
    dest.open (DEST, std::ios::binary); // same again, binary
    if (!src.is_open() || !dest.is_open())
        return false; // could not be copied

    dest << src.rdbuf (); // copy the content
    dest.close (); // close destination file
    src.close (); // close source file

    return true; // file copied successfully
}

int main ()
{
    char* libvar;
    string filepath = "\\new\\input2.txt";

   // Get the value of the LIB environment variable.
   libvar = getenv( "LIB" ); // C4996
   // Note: getenv is deprecated; consider using getenv_s instead

   if( libvar != NULL )
      printf( "Original LIB variable is: %s\n", libvar );
    ifstream f1 ("input.txt",fstream::binary);
    //ofstream f2 (libvar, "\\new\\input2.txt", fstream::trunc|fstream::binary);
    //f2<<f1.rdbuf();

   // Attempt to change path. Note that this only affects the environment
   // variable of the current process. The command processor's
   // environment is not changed.
   // Note: _putenv is deprecated; consider using putenv_s instead

    if (!copyFile ("input.txt", libvar + "\\new\\input2.txt"))
        std::cout << "File could not be copied successfully";
    else
        std::cout << "File copied successfully!";

    std::cin.get (); // pause for input
    //return EXIT_SUCCESS; // program was executed successfully

   return 0;
}

i tried it but always gets errors

Code:

error C2110: cannot add two pointers

Am using VC++ 6.0

There are a few ways, for example:

Code:

std::string libvar(getenv("LIB"));

// ...

if (!copyFile("input.txt", (libvar + "\\new\\input2.txt").c_str()))

Originally Posted by bakri

Am using VC++ 6.0

Why are you not using a more recently released compiler?

i used

Code:

std::libvar(getenv("LIB"));

.. i forget string


i got VC++ 2010 without FMC
thanx 4 help LaserLight

i got problem..
Yes its compiled but closed with error.
this is new code:

Code:

#include <fstream>
#include <string>
#include <iostream>

using namespace std;

bool copyFile (const char SRC[], const char DEST[])
{
    std::ifstream src; // the source file
    std::ofstream dest; // the destination file
    src.open (SRC, std::ios::binary); // open in binary to prevent jargon at the end of the buffer
    dest.open (DEST, std::ios::binary); // same again, binary
    if (!src.is_open() || !dest.is_open())
        return false; // could not be copied

    dest << src.rdbuf (); // copy the content
    dest.close (); // close destination file
    src.close (); // close source file
    return true; // file copied successfully
}

int main ()
{

   // Get the value of the LIB environment variable.
   //libvar = getenv( "LIB" ); // C4996
    std::string libvar(getenv("LIB"));

  if(libvar.c_str() != NULL )
      printf( "Original LIB variable is: %s\n", libvar );

    if (!copyFile("input.txt", (libvar + "\\new\\input2.txt").c_str()))
        std::cout << "File could not be copied successfully";
    else
        std::cout << "File copied successfully!";
    std::cin.get (); // pause for input
   return 0;
}

And this is the error:

Code:

cp.exe has encountered a problem and needs to close.
We are sorry for the inconvenience.

You can not print a C++ std::string with printf(). Use the C++ streams instead. Also you shouldn't be using the C++ extraction and insertion operators << >> when reading and writing binary files. You should be using the read and write member functions.

Jim

ahaa.. am new in c++ and like to do tutorials.. now i got it
am downloading and writing the tutorials from books and overnet because no one near me know much in c/c++

thanks JIM.. you solved my error