csci5271/hw1/hw1p2b.c


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#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>
void silly_function(char *pathname) {
  struct stat f, we;
  int rfd, wfd;
  char *buf;
  stat(pathname, &f);
  stat("./critical", &we);
  if (f.st_dev == we.st_dev && f.st_ino == we.st_ino) {
    return;
  }
  rfd = open(pathname, O_RDONLY);
  buf = malloc(f.st_size - 1);
  read(rfd, buf, f.st_size - 1);
  close(rfd);
  stat(pathname, &f);
  if (f.st_dev == we.st_dev && f.st_ino == we.st_ino) {
    return;
  }
  wfd = open(pathname, O_WRONLY | O_TRUNC);
  write(wfd, buf, f.st_size - 1);
  close(wfd);
  free(buf);
}

int main() { silly_function("./not"); }