how to copy a text file with VC++

WhiteMage> these are quite ugly windows solutions ...

BOOL WINAPI CopyFile(
  __in  LPCTSTR lpExistingFileName,
  __in  LPCTSTR lpNewFileName,
  __in  BOOL bFailIfExists
);

CopyFile("OldFile.txt","NewFile.txt",TRUE);

Hi WhiteMaqe,
Thanks for the solution.
I did not think about the portability issue.
I will use this solution and later write a small function that does it with C++ I/Oå

Hi flob9,
Thanks for your solution.
Is your solution portable to system other than WINDOWS?

No, this is windows only.

For linux, you need something like WhitMage solution #3.

Here is some linux code (with permissions copying)

    char buffer[FILEBUFF];
    int s, d, bytes, ret;
    struct stat sb;
 
    if((s = open(src, O_RDONLY|O_BINARY)) == -1)
        return -1;
 
    if((d = open(dest, O_CREAT|O_WRONLY|O_TRUNC|O_BINARY)) == -1) {
        close(s);
        return -1;
    }
 
    while((bytes = read(s, buffer, FILEBUFF)) > 0)
        write(d, buffer, bytes);
 
    close(s);
    ret = close(d);
 
    stat(src, &sb);
    chmod(dest, sb.st_mode);
 
 
// source : http://google.com/codesearch/p?hl=fr&sa=N&cd=14&ct=rc#jjvC9LP091w/clamav-0.91.1/shared/misc.c&q=filecopy%20lang:c
                                              

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Here is the simplified snippet from my real code. It uses STL only; hence, should be portable.

    void copyfile(const std::string & src, const std::string & dst)
    {
        // Test whether you do not copy the file into itself.
        
        // Open the source for reading.
        ifstream fsrc(src.c_str(), ios::in | ios::binary);
        if ( ! fsrc.is_open())
        {
            ostringstream ostr;
            ostr << "File '" << src << "' could not be open for reading.";
            throw runtime_error(ostr.str());
        }
 
        // Open the destination file for writing.
        ofstream fdst(dst.c_str(), ios::out | ios::binary);
        if ( ! fdst.is_open())
        {
            fsrc.close();     // close the previously opened source file
            ostringstream ostr;
            ostr << "File '" << dst << "' could not be open for writing.";
            throw runtime_error(ostr.str());
        }
 
        // Copy the content.
        fdst << fsrc.rdbuf();
 
        // Close the files.
        fsrc.close();
        fdst.close();
    }
                                              

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Hi flob9
I get the following error when trying to compile your first solution:

error C2664: 'CopyFileW' : cannot convert parameter 1 from 'const char [12]' to 'LPCWSTR'
1>        Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
////////////////////////////////////////////////////////////////////////////////////////////////////////////

Hi pepr
I get the following errors when trying to compile your function: (here are some of the errors)

c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(84) : error C3861: 'runtime_error': identifier not found
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(88) : error C2065: 'fdst' : undeclared identifier
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(88) : error C2065: 'fsrc' : undeclared identifier
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(88) : error C2228: left of '.rdbuf' must have class/struct/union
1>        type is ''unknown-type''
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(91) : error C2065: 'fsrc' : undeclared identifier
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(91) : error C2228: left of '.close' must have class/struct/union
1>        type is ''unknown-type''
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(92) : error C2065: 'fdst' : undeclared identifier
1>c:\documents and settings\user3\my documents\visual studio 2008\projects\try10\try10\try10.cpp(92) : error C2228: left of '.close' must have class/struct/union
1>        type is ''unknown-type'

Ok, thats because your project is unicode.

Try this :

CopyFile(L"OldFile.txt",L"NewFile.txt",TRUE);


BTW, if you want a portable code, consider pepr solution (and you need some includes to get it working).

Hi flob9.
How can I use the CopyFile command  that the filename will be inside a variable:
something like:?

char name[30];
strcpy_s(name,"OldFile.txt");

CopyFile(Lname,L"./try/NewFile.txt",TRUE);