#!/bin/zsh

MKTEMP=$(which mktemp)
[ -x $MKTEMP ] || exit
TMP=$(mktemp --tmpdir $(basename $0).XXXXXXXXXX)

aptitude update > /dev/null 2>> $TMP
aptitude --simulate --assume-yes upgrade 2>&1 >> $TMP

( diff -ru - $TMP >/dev/null <<EOF 
Reading package lists...
Building dependency tree...
Reading state information...
Reading extended state information...
Initializing package states...
Reading task descriptions...
No packages will be installed, upgraded, or removed.
0 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B of archives. After unpacking 0 B will be used.
Would download/install/remove packages.
EOF
) || ( cat - $TMP <<EOF
From: Root Fachschaften Uni Muenchen <root@fs.lmu.de>
To: Root Fachschaften Uni Muenchen <root@fs.lmu.de>
Subject: $(hostname) upgrades

EOF
) | sendmail -t

rm $TMP