tty_resize (neé resize)
=======================

This is a little and fast standalone utility based on old X sources that reads
current tty size from the terminal emulator and synchronizes the width and
height currently set in the system with the TIOCGWINSZ ioctl. It makes sense
**only when you are connecting your TTY emulator over a serial link.**

When you are connected remotely over ssh, the TTY resize signal is sent in the
SSH protocol, which informs the system that the tty was resized. Programs on the
tty in turn get the SIGWINCH signal may handle it to redraw their screen to
conform to the new size. Serial protocol (agetty) lacks this capability. When
working over a serial line, run it e.g. as part of bash PROMPT_COMMAND, so that
the system's idea of your TTY size stays more or less in-sync with true emulated
TTY geometry. SIGWINCH-aware programs, such as vim, less or htop won't resize
automatically (unless you explicitly run tty_resize from them), but will be at
least read the new size on a next launch. This is probably as far as you can get
over a serial tty connection.

Build
-----

A single ~15KB executable file installs into /usr/local/bin by default.

GNU Make:
   make
   sudo make install [ PREFIX=/instead_of/usr/local ]
   make dist-clean

CMake:
   cmake -B Build
   cmake --build Build
   sudo cmake --install Build --strip [ --prefix=/instead_of/usr/local ]
   rm -rf Build

Historical record
-----------------

Salvaged and upgraded for modern C by kkm in 2019 from:
http://web.archive.org/web/20081224152013/http://www.davehylands.com/gumstix-wiki/resize/resize.c
Thanks to the answer https://unix.stackexchange.com/a/19265
    kkm, December 2019

 * * *

This version of resize.c has been modified from the original, which
came with X11/xterm.  It no longer tries to emit shell commands for
setting LINES, COLUMNS, or TERMCAP.  It assumes an ANSI terminal,
and the availability of the TIOCGWINSZ ioctl.  The portability
ifdefs were also removed -- posix termios access is assumed.
    Paul Fox, June 2006

Copyright And License
---------------------

SPDX-License-Identifier: BSD-3-Clause

Copyright 1987 Digital Equipment Corporation
          2006 Paul Fox
          2019 Cy "kkm" K'Nelson

See the LICENSE file for full licenses and comments. The BSD 3-clause license
was chosen specifically to comply with the terms of the original license.