How do I make the apple terminal window auto change colour scheme when I ssh to a specific server

Question

When I ssh into a remote production server I would like the colour scheme of my terminal window to change to something brigh and scary, preferably red, to warn me that I am

Answer 1

Xterm-compatible Unix terminals have standard escape sequences for setting the background and foreground colors. I'm not sure if Terminal.app shares them; it should.

case $HOSTNAME in
    live1|live2|live3) echo -e '\e]11;1\a' ;;
    testing1|testing2) echo -e '\e]11;2\a' ;;
esac

The second number specifies the desired color. 0=default, 1=red, 2=green, etc. So this snippet, when put in a shared .bashrc, will give you a red background on live servers and a green background on testing ones. You should also add something like this to reset the background when you log out.

on_exit () {
    echo -e '\e]11;0\a'
}
trap on_exit EXIT

---

EDIT: Google turned up a way to set the background color using AppleScript. Obviously, this only works when run on the same machine as Terminal.app. You can work around that with a couple wrapper functions:

set_bg_color () {
    # color values are in '{R, G, B, A}' format, all 16-bit unsigned integers (0-65535)
    osascript -e "tell application \"Terminal\" to set background color of window 1 to $1"
}

sshl () {
    set_bg_color "{45000, 0, 0, 50000}"
    ssh "$@"
    set_bg_color "{0, 0, 0, 50000}"
}

You'd need to remember to run sshl instead of ssh when connecting to a live server. Another option is to write a wrapper function for ssh that scans its arguments for known live hostnames and sets the background accordingly.