…or Howto disable the startup chime

Well there is already a gui-based solution for that problem, called:

StartUpSound.prefPane

But maybe you prefer a command-line based method

I found that hint on macosxhints.com

Basic idea:

• We create 2 files:
  • (1) Mute the sounds while shutdown. This script will save the previous volume
  • (2) Unmute the volume, if it was muted

Now lets see the scripts:

(1) /etc/rc.shutdown.local

#!/bin/sh

OSA=/usr/bin/osascript

echo OUTPUT_MUTED=`$OSA -e “output muted of (get volume settings)”`
> /etc/volume.settings

$OSA -e “set volume with output muted”

and (2) /etc/rc.local

#!/bin/sh

OSA=/usr/bin/osascript

if [ -r /etc/volume.settings ]; then
. /etc/volume.settings

# If the volume wasn’t muted before shutting down, unmute it on
# startup
if [ $OUTPUT_MUTED = "false" ]; then
$OSA -e “set volume without output muted”
fi
fi

Tags: /etc/rc.local, /etc/rc.shutdown.local, boot-sound, cli, macosxhints.com, mute, StartUpSound.prefPane, unmute