bleh

#include <sys/mman.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>

#define IMG     "./english.dsk"
const off_t offset = 0x0468c00;
#define S_OFFSET "OFFSET"
#define SIZE    60

int edit(char *v) {
  int fd;
  char *mem;
  struct stat s;
  off_t pa_offset, diff;
  pa_offset = offset & ~(sysconf(_SC_PAGE_SIZE) - 1);
  printf("PA_OFFSET = %d, offset = %d\n", pa_offset, offset);
  diff = offset - pa_offset;
  if ((fd  = open(IMG, O_RDWR)) == -1) {
   perror("open");
  } else {
   fstat(fd, &s);
   if ((mem = mmap(NULL, SIZE + diff, PROT_READ | PROT_WRITE, MAP_SHARED, fd, pa_offset)) == MAP_FAILED) {
    perror("mmap");
  }
   memset(&mem[diff], 0, SIZE);
   memcpy(&mem[diff], v, strlen(v));
   if (msync(mem, SIZE + diff, MS_SYNC|MS_INVALIDATE)) {
    perror("msync");
   }
   if (munmap(mem, SIZE + diff)) {
    perror("munmap");
   }
   close(fd);
  }
}
int usage(char *v) {
  return printf("usage: %s BLAH\n", v);
}

int main(char c, char **v) {
  if (c < 2) return usage(v[0]);
  if (strlen(v[1]) > SIZE) {
    return(printf("Sorry, %d is too big.\n", strlen(v[1])));
  }
  printf("edit_img %s\n", v[1]);
  return (edit(v[1]));
}