Changes iTerm2's background color based on host configuration

sshColor

#!/bin/bash
# Installation:
# 1. Save this script to /some/bin/sshColor
# 2. chmod 755 /some/bin/sshColor
# 3. alias ssh=/some/bin/sshColor
# 4. Configure your host colors below.
# 
# checked: GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin17)

# Configuration:
# The color(foreground, backgroun) and opacity
SSHCOLOR_DEFAULT=(ffffff 001f1f 0)
SSHCOLOR_PRODUCTION=(ffffff 220000 0.1)
SSHCOLOR_STAGING=(ffffff 000022 0.1)
SSHCOLOR_REMOTE=(ffffff 000000 0.1)

# The regexp of host group
REGEXP_PRODUCTION=prod
REGEXP_STAGING=stg

# Function:
# Set the colors of background and tab
set_colors() {
  local HEX_FG=$1
  local HEX_BG=$2
  local OPACITY=$3

  local FG_R=`echo $HEX_FG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$1 * 257)}'`
  local FG_G=`echo $HEX_FG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$2 * 257)}'`
  local FG_B=`echo $HEX_FG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$3 * 257)}'`
  local BG_R=`echo $HEX_BG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$1 * 257)}'`
  local BG_G=`echo $HEX_BG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$2 * 257)}'`
  local BG_B=`echo $HEX_BG | sed 's/../0x&,/g' | awk -F "," '{printf("%d",$3 * 257)}'`

  if [[ "$HEX_BG" =~ "${SSHCOLOR_DEFAULT[1]}" ]]; then
    tab_reset
  else
    tab_color $BG_R $BG_G $BG_B
  fi

  bg_color $FG_R $FG_G $FG_B $BG_R $BG_G $BG_B $OPACITY
}

# Set background colors
bg_color() {
  /usr/bin/osascript <<EOF
tell application "iTerm"
  tell current session of first window
    set foreground color to {$1, $2, $3}
    set background color to {$4, $5, $6} 
    set transparency to "$7"
  end tell
end tell
EOF
}

# Set tab color
tab_color() {
  echo -ne "\033]6;1;bg;red;brightness;$1\a"
  echo -ne "\033]6;1;bg;green;brightness;$2\a"
  echo -ne "\033]6;1;bg;blue;brightness;$3\a"
}

# Back to default tab
tab_reset() {
  echo -ne "\033]6;1;bg;*;default\a"
}

# hack Ctrl-c to back to default all
trap 'echo "Interrupted."; set_colors SSHCOLOR_DEFAULT; exit;' INT

if [[ "$@" =~ $REGEXP_PRODUCTION ]]; then
  set_colors ${SSHCOLOR_PRODUCTION[@]}
elif [[ "$@" =~ $REGEXP_STAGING ]]; then
  set_colors ${SSHCOLOR_STAGING[@]}
else
  set_colors ${SSHCOLOR_REMOTE[@]}
fi

ssh $@

# back to default all
set_colors ${SSHCOLOR_DEFAULT[@]}