#!/bin/bash

if [[ $1 == "-d" ]]; then
    shift
    setgetty=1
else
    setgetty=
fi

if [[ $1 -ne 300 && $1 -ne 1200 && $1 -ne 2400 && $1 -ne 4800 && $1 -ne 9600 && $1 -ne 19200 && $1 -ne 38400 && $1 -ne 57600 && $1 -ne 115200 ]]; then
    echo 'Usage: baud [-d] 300|1200|2400|4800|9600|19200|38400|57600|115200';
    echo '  -d sets default speed for all serial port shells (takes effect on logout)'
    echo '  omitting -d makes change temporary and immediate'
else
    if [[ $setgetty ]]; then
        sudo sed -i "s/ttyAMA0 .* /ttyAMA0 $1 /" /etc/inittab;
        sudo sed -i "s/ttyAMA0,[0-9]*/ttyAMA0,$1/g" /boot/cmdline.txt;
        sudo sed -i "s/\(ttyUSB.*\) .* /\1 $1 /g" /etc/inittab;
        sudo init q;
        sudo pkill -f "/sbin/getty"
    else
        if [[ $(tty | grep tty) ]]; then
            stty -F $(tty) $1
        fi
    fi
fi

echo -e "$(tput bold)$(tty) current $(stty -a -F $(tty) | grep -o 'speed .* baud')$(tput sgr0)"
echo -e "$(tput bold)default speed at login: $(grep ttyUSB /etc/inittab | sed 's/^.*ttyUSB[^ ]* \(.*\) .*$/\1/') baud$(tput sgr0)"