Copying Binary Files

Question

I'm trying to figure out how to copy binary files from one place to another .exe's. I can't seem to find any solutions to learn.

I'm using Windows. What's the best way to do it?

Answer 1

What do you mean "best way"? I think this is the most straightforward way ... hopefully that is what you meant :)

---

fopen the input and output files with binary mode

FILE *exein, *exeout;

exein = fopen("filein.exe", "rb");
if (exein == NULL) {
    /* handle error */
    perror("file open for reading");
    exit(EXIT_FAILURE);
}
exeout = fopen("fileout.exe", "wb");
if (exeout == NULL) {
    /* handle error */
    perror("file open for writing");
    exit(EXIT_FAILURE);
}

fread and fwrite

size_t n, m;
unsigned char buff[8192];
do {
    n = fread(buff, 1, sizeof buff, exein);
    if (n) m = fwrite(buff, 1, n, exeout);
    else   m = 0;
} while ((n > 0) && (n == m));
if (m) perror("copy");

and finally close the files

if (fclose(exeout)) perror("close output file");
if (fclose(exein)) perror("close input file");

Have fun!