RE: [PATCH 1/1] fport_print: handle ttyname ENODEV

[Rob Browning]

Maxime Devos <maximede...@telenet.be> writes:

> It’s simply the case that SCM_SYSCALL is slightly the wrong tool here,
> so a slight variant is needed.

Good point.  How about this:

  SCM
  scm_i_c_ttyname (int fd)
  {
    // Return the string ttyname or the integer errno.  We can remove the
    // + 1 if we become confident POSIX requires TTY_NAME_MAX to include
    // the trailing null.  Assumes TTY_NAME_MAX < SIZE_MAX.
    int err = 0;
    char name[TTY_NAME_MAX + 1];

  #ifdef HAVE_TTYNAME_R
    SCM_SYSCALL (err = ttyname_r (fd, name, TTY_NAME_MAX));
  #else // HAVE_TTYNAME
    char *global_name;
    while(1)
      {
        // ttyname() may use a shared global buffer
        scm_i_pthread_mutex_lock (&scm_i_misc_mutex);
        global_name = ttyname (fd);
        err = errno;
        scm_i_pthread_mutex_unlock (&scm_i_misc_mutex);
        if (global_name || err != EINTR)
          break;
        scm_async_tick ();
      }
    strcpy(name, global_name);
  #endif // HAVE_TTYNAME

    if (err)
      return scm_from_int(err);
    else
      return scm_from_locale_string (name);
  }

Thanks
-- 
Rob Browning
rlb @defaultvalue.org and @debian.org
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