Unique Hostname Colorization

gistfile1.sh

# Calculate a short checksum of the real hostname to determine a unique color
if [[ $TERM =~ "256color" ]]; then
   host_color="38;5;$((16 + $(hostname | cksum | cut -c1-3) % 256))";
else
   host_color="1;$((31 + $(hostname | cksum | cut -c1-3) % 6))";
fi

I think the algorithm is ripe for improvement; the checksum idea came from here, all I did was add some rudimentary 256color support. There're definitely better ways to map hostnames to colors in a more visually informative manner. I'll hack on this a bit.

thanks for the link. i'm looking at xterm-colortest -w output http://i.imgur.com/SEO41.png and it would seem you can split the palette in half for light and dark, i.e. for light background you can do bad_color - 18 = good_color. problem is afaik there is no way to really determine what color scheme client is using systematically aside from COLORFGBG variable (http://stackoverflow.com/questions/2507337/is-there-a-way-to-determine-a-terminals-background-color/7760031#7760031) and even this seems to restricted to rxvt and compatibles, i.e. xterm for example doesn't set it. but i guess it is reasonable to make user set this for themselves if they desire this functionality?

btw im also doing USER_COLOR with this now :)

ok so coming up with a comprehensive light vs dark solution is currently more than i can handle. my immediate issue with bad colors was resolved by using cut 1-4, which pushes my current main use case colors into more suitable territory (darker text on light bg).

http://www.frexx.de/xterm-256-notes/ has part of an xterm2rgb function whose concept could possibly be of use here. if we draw a diagonal line through the palette (read also http://particletree.com/notebook/calculating-color-contrast-for-legible-text/), there are certain hex patterns that will then just need to be reversed for light vs dark.

but to detect between light and dark, i see no other way than for the user to take care of it by using a COLORFGBG-compatible terminal or taking care of this whole PS1 shebang in personal .bashrc.

on a system bashrc level where you would need to already know COLORFGBG when you do anything in /etc/bash/bashrc, only way is to probably forward that variable within .ssh/config. if it doesn't exist, then a comprehensive system wide solution for this doesn't seem possible at the time.