tty_size/2

Availability:built-in

Determine the size of the terminal. Platforms:

Unix: If the system provides ioctl calls for this, these are used and tty_size/2 properly reflects the actual size after a user resize of the window. The ioctl is issued on the file descriptor associated with the user_input stream. As a fallback, the system uses tty_get_capability/3 using li and co capabilities. In this case the reported size reflects the size at the first call and is not updated after a user-initiated resize of the terminal.
Windows: Getting the size of the terminal is provided for swipl-win.exe. The requested value reflects the current size. For the multithreaded version the console that is associated with the user_input stream is used.