Fastest way to do this

[acidx]

I posted this in another part of this board and didn't get a response, maybe here I will.

Ok, so today I've been working on an executable dropper source code generator, and I ran into some problems. Well when I load the files I have to store the file data into a character array. I've gotten this part to work, so i can print to the output src file the following:

unsigned char File1[6] = { 0x4D, 0x5A, 0x90, 0x00, 0x03, 0x00 }

Now my question is, what is the fastest way to go about loading a file and then generating a string like the above? because going byte by byte in the file is actually rather slow if its a a 65kb file. Maybe someone can direct me in the right direction please?

[Luis G]

You can always read a bunch of bytes (a struct is my choice) and then read one by one out of the memory.

Reading small packets of 256 or 512 bytes should improve the performance.

[kuphryn]

What are you trying to do? I understand that you want to read in a file, but what do you want to print?

Kuphryn

[Luis G]

As i understood, he's trying to parse a file and print the output to another file.

Thou, we need more details to help further.

[Philip Nicoletti]

If the files are rather small such as 65K, you can create
a charr array and read it in as follows. You need to
delete [] afterwards of course. You can use
vector<char> instead. In tests that I have run on
various compilers, it tends to be only slight slower,
and you don't have to clean-up memory.



#include < iostream >
#include < fstream >
#include < ctime >

using namespace std;

int main()
{
std::ifstream in("pp1.txt",std::ios::binary);
if (!in)
{
std::cout << "problem with file open" << std::endl;
return 0;
}

clock_t c1,c2;

c1 = clock();

in.seekg(0,std::ios::end);
unsigned long length = in.tellg();
in.seekg(0,std::ios::beg);

char *szFileText = new char[length+1];
in.read(szFileText,length);
szFileText[length] = 0;

// when done

delete [] szFileText;


c2 = clock();

std::cout << static_cast< double >(c2-c1)/static_cast< double >(CLOCKS_PER_SEC) << std::endl;

return 0;
}

[Nyromant]

Erm,do you want the bytes hardcoded or are these bytes read in runtime?

if you want to hardcode them you may write a small program which does the formatting of the array

you may do this like that:
first,write "{ " in the output-file,then do this:
read a byte from sourcefile and and store it,now use itoa(thebyte,charholder,RADIX) and write that string (charholder) to the file followed by " , ".
Do this for every byte in the file (Keep in mind that this would increase the filesize enormous) and complete the output-file with " }",finished
(result should like { 120 ,100 ....})
now just copy that array {} to your sourcecode

you may also write the hexstrings,but i dunno which function to use for that (i´ve also seen this question in visual c++ forum i think)

hth