brew-update-notifier.sh

#!/bin/bash
#
# Notify of Homebrew updates via Notification Center on Mac OS X
#
# Author: Chris Streeter http://www.chrisstreeter.com
# KLK: Fixed package lists and do not show notification when there are no updates
#
# Requires: terminal-notifier. Install with:
#   brew install terminal-notifier

BREW_EXEC=$(which brew)
TERMINAL_NOTIFIER=$(which terminal-notifier)
#TERMINAL_NOTIFIER=/bin/echo
NOTIF_ARGS="-sender com.apple.Terminal"

$BREW_EXEC update > /dev/null 2>&1
outdated=$($BREW_EXEC outdated)
pinned=$($BREW_EXEC list --pinned)

# Remove pinned formulae from the list of outdated formulae
outdated=$(comm -1 -3 <(echo -e "$pinned") <(echo -e "$outdated"))

if [ -z "$outdated" ] ; then
    if [ -e $TERMINAL_NOTIFIER ]; then
        # No updates available
        #$TERMINAL_NOTIFIER $NOTIF_ARGS \
            #-title "No Homebrew Updates Available" \
            #-message "No updates available yet for any homebrew packages."
        exit 0
    fi
else
    # We've got an outdated formula or two

    # Nofity via Notification Center
    if [ -e $TERMINAL_NOTIFIER ]; then
        lc=$(echo "$outdated" | wc -l)
        outdated=$(echo "$outdated" | tail -n ${lc})
        message=$(echo "$outdated" | head -5)
        if [ "$outdated" != "$message" ]; then
            message="Some of the outdated formulae are:
$message"
        else
            message="The following formulae are outdated:
$message"
        fi
        # Send to the Nofication Center
        $TERMINAL_NOTIFIER ${NOTIF_ARGS} -title "Homebrew Update(s) Available" -message "${message}"
    fi
fi