twitch --help

# Watches for .pyc files at any depth and deletes
# them when created or modified.
twitch --debounce 0 -p '**/*.pyc:rm $FILE'

# Watches .cabal files and reconfigures when they change.
# Also watches .hs files at any depth in the src folder
# and rebuilds the project when they change.
twitch -p '*.cabal:cabal configure && cabal build' -p 'src/**/*.hs:cabal build'

# Watches all .log files in /var/log and prints their last line
# when they change.
twitch --debounce 0 -p '/var/log/*.log:tail -n 1 $FILE'