gistfile1.txt

#!/usr/bin/env bash
#
#  Simple script to toggle fan speed for thinkpad laptops from auto to 
#  full-speed.  Need sudo or custom group made to access /proc/acpi.
#  Also needs fan_control=1 in thinkpad_acpi kmod options.

# Automatically abort on error.
set -e

# Read current fan speed. Made constant (declare -r) since it won't be changed
# after initialization.
declare -r cur_speed="$(cat /proc/acpi/ibm/fan | egrep -i "^level:" | awk '{print $2}')"

if [[ "$cur_speed" == "auto" ]]; then
  # No block scope in bash, so we can declare swap_speed in here, making it a
  # bit clearer what the possible values are.
  swap_speed="full-speed";
else
  swap_speed="auto"
fi

# If this fails, set -e will abort the script before we get to notify-send.
echo "level $swap_speed" | sudo tee /proc/acpi/ibm/fan
notify-send "Changed fan speed to $swap_speed."