#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
// #include <tls.h>

#ifdef __linux__
# include <pty.h>
#elifdef __OpenBSD__
# include <termios.h>
# include <util.h>
# include <sys/ioctl.h>
#else
# error "sorry, unknown platform. please hack."
#endif

#include <ovm.h>

void
nonblock(int p)
{
  int v = fcntl(p, F_GETFL);
  fcntl(p, F_SETFL, v|O_NONBLOCK);
}

word
prim_custom(int op, word a, word b, word c)
{
  switch (op) {
  case 400: { /* openbash → fd */
    int m, s;
    openpty(&m, &s, NULL, NULL, NULL);
    nonblock(m);
    nonblock(s);
    if (fork() == 0) {
      setsid();
      ioctl(s, TIOCSCTTY, 0);

      dup2(s, STDIN_FILENO);
      dup2(s, STDOUT_FILENO);
      dup2(s, STDERR_FILENO);

      close(m);
      close(s);
      execlp("bash", "-i", NULL);
      exit(42);
    } else {
      close(s);
      return mkport(m);
    }
  }
  default:
    return IFALSE;
  }
}