Like the commentators before me mentioned there is no alternative to calling resize after every command, if you don't have this command and you don't want to install a package where it's in (xterm), here are two POSIX shell script that do the same using ANSI terminal escape codes:
res() {
old=$(stty -g)
stty raw -echo min 0 time 5
printf '\0337\033[r\033[999;999H\033[6n\0338' > /dev/tty
IFS='[;R' read -r _ rows cols _ < /dev/tty
stty "$old"
# echo "cols:$cols"
# echo "rows:$rows"
stty cols "$cols" rows "$rows"
}
res2() {
old=$(stty -g)
stty raw -echo min 0 time 5
printf '\033[18t' > /dev/tty
IFS=';t' read -r _ rows cols _ < /dev/tty
stty "$old"
# echo "cols:$cols"
# echo "rows:$rows"
stty cols "$cols" rows "$rows"
}
resis based on the solution presented at https://wiki.archlinux.org/index.php/working_with_the_serial_console#Resizing_a_terminal. It works as follows:res2is influenced byresize.shfrom xterm (see https://github.com/ThomasDickey/xterm-snapshots/blob/master/vttests/resize.sh). It uses a specificxtermcode for getting the information we want (implemented in many terminal emulators), see: http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-Functions-using-CSI-_-ordered-by-the-final-character_s_ ("Report the size of the text area in characters.").
BTW, in my .profile file you will find the following:
[ $(tty) = /dev/ttyS0 ] && res
so that the the terminal size is determined on every login over the serial line (the one I use for management), e.g. after you reboot the device.
See also the idea by rsawrsaw in the comments to have the line [ $(tty) = /dev/ttyS0 ] && trap res2 DEBUG there instead so the resizing runs after every command (note that AFAIK it's not or not always possible on busybox though).
