Getting a hexadecimal number into a program via the command line

Question

I can do this:

int main(int argc, char** argv) {
  unsigned char cTest = 0xff;
  return 0;
}

But what's the right way to get a hexadecimal number into the program via the command line?

unsigned char cTest = argv[1];

doesn't do the trick. That produces a initialization makes integer from pointer without a cast warning.

Answer 1

I think some people arriving here might just be looking for:

$ ./prog `python -c 'print "\x41\x42\x43"'`
$ ./prog `perl -e 'print "\x41\x42\x43"'`
$ ./prog `ruby -e 'print "\x41\x42\x43"'`