reading .exe file with ifstream by binary

Question

1.00/5 (1 vote)

See more:

as the title said, I tried to read a .exe file using ifstream in binary way. but it always miss some bytes, so the newly copied .exe file is not legal. I tried to comment the f_write statement, the problem still there.

code looks like following.

C++

int main(int argc, char *argv[])
{
        if (argc != 3)
        {
                cerr << "Error! \n filecopy.exe srcfilename destfilename" << endl;
                return 0;
        }
        
        ifstream f_read (argv[1],ios::binary | ios::in);
    	ofstream f_write(argv[2],ios::binary | ios::out);

        char i;

        if (f_read == NULL)
        {
          return 0;
        }
                
        while (f_read >> i)
        {
           f_write << i;
        }

        f_read.close();
        f_write.close();

        return 0; 
}

Any tips will be appreciate.

Posted 20-Jul-13 8:20am

BCN-163

Add a Solution

Comments

Sergey Alexandrovich Kryukov 21-Jul-13 1:10am

Okay, you can read EXE file, but what are you going to do with it? If you want to parse it, this is a well-known problem, you can find enough code samples...
—SA

BCN-163 21-Jul-13 23:28pm

thanks for your reply. just want to find out the reason. no really job to do.

2 solutions

Solution 2

@pasztoripisti thanks very much. it works.

Posted 21-Jul-13 17:38pm

BCN-163

Comments

pasztorpisti 22-Jul-13 3:15am

You are welcome! Next time use the "Have a Question or Comment" button below the answer you want to comment on instead of adding the comment as an answer, that way the answer owner receives notification about your message.

BCN-163 29-Jul-13 2:10am

OK, I got it.thank you.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

pasztorpisti · Accepted Answer · 2013-07-20T09:25:00

Probably the newline characters (ascii 10 or 0x0a) are skipped by the iostream object when you are reading in the bytes. Try inserting the following line before doing the copy:

C++

f_read.unsetf(ios::skipws);

EDIT: copying a file byte-by-byte is not effective. Reading in the whole file and then writing it out in one big piece is also a bad idea as in that case you wouldn't be able to copy huge files. The best is the golden middle way, using a buffer (few, maybe 4-16 kilobytes) as a unit for reading/writing data to be effective.