Problem with coping an exe file

[tezcatlipooca]

Hi all,
i have written some code just to copy an executable but when i try to run the copy, a get an error(using Windows XP SP 2)
"Copiedfile.exe is not a valid win32 application"
and i can't understand why. When i load both files(prototype and copy) at a hex editor they seem to be exactly the same.
May someone help, i would me most grateful.
Anyway thanks for your time!

[quzah]

Right there. See? On that line you've made an error. Fix that one, then I'll show you the next one.


Quzah.

[tezcatlipooca]

Ok man, sorry, i just thought that it had something to do with the OS and not with my code.
Here:

#include <stdio.h>
#include <string.h>
int main(){
    FILE *ptr;
    FILE *ptrout=fopen("fileb.exe","wb");
     long size=0,i;
    if(ptr=fopen("filea.exe","rb"));
    else printf("could not open file");
     fseek (ptr, 0, SEEK_END);
                               size = ftell (ptr);
                               
                               rewind (ptr);
    printf("size=&#37;d\n",size);
    system("pause");
    for(i=0;i<size;i++){
    
   fputc(fgetc(ptr),ptrout);
    printf("i=%d\n",i);}
    fclose(ptr);
    fclose(ptrout);
    
    printf("Successfully Copied!\n");
    
    system("pause");
    return 0;}

[dwks]

if(ptr=fopen("filea.exe","rb"));

Many compilers warn you about that and require you to put in extra parentheses

if( ( ptr=fopen("filea.exe","rb") ) );

but I have no idea why. I'm sure Quzah does though.

It appears to work well with my (Linux) system. There's no need to determine the filesize beforehand, though.

I suspect that you're trying to get it to open itself. Most Windows systems don't allow this.

My only other point is that for UNIX-like systems, you'd probably need to change the file's permissions before executing the new executable.