Nothing (bash style)

The brunerd blog has been a whole lot of nothing lately, so let’s commemorate and celebrate with an entry featuring the premiere of the bash tag and category… hmm, which one is more useful? We’ll find out. Now as for nothing, there’s a legit command, special built-in to do nothing in bash!

man page for bash command :


: [arguments]

No effect; the command does nothing beyond expanding arguments and performing any specified redirections.  A zero exit code is returned.


Isn’t that lovely? When you need to do nothing, you can call :
Perhaps you are writing a script and aren’t sure what you’ll do for that if statement —

if [ "${this}" == "that" ]; then
#actually not sure what to do here, let's do nothing
echo "This else, I'll do"

I made a gist here and I think I’ll keep making more. I’ll feature them here with the bash tag, if only as an auxillary backup of my brain and to add to the collective patchwork quilt of code we all use to get our ideas off the ground, when our reach is just a hare shy of grasp and we need a little help.

Also in the gist was a snippet of a novel use by kbeck at Extensis in his UTC removal script to use : to redirect a here document into itself and server as a comment block that doesn’t need # on every line to be treated as a comment —


[ ] 2016-0324: enclose me; love me. i am a block of comments



RecoveryHD Updater now with PKG building

** Update: Recovery HD updaters packages for 10.11 will only work when run in OS X 10.11, previous packages could run in different OSesnot so for 10.11

Updated April 6, 2015: createRecoveryHDUpdater 15.4.6.command – built PKG now is targetable to volumes other than /

Released Feb 28, 2015: createRecoveryHDUpdater 15.2.28.command


Building off the previous work the updated script will now create a nicely named dmg


Containing both an interactive script for updating disks and a new script to create a .pkg!



The fruits of RecoveryHD PKG Maker.command:

recoverypkg_iconCustom Bundle ID is interactively provided, the PackageVersion is matched to the OS release. Signing identity is asked for in the script but not tested (my cert might be broken, YMMV). The target of the package is always / – an exercise for the reader to change the postinstall script to use Installer’s variables to affect the target The exercise to make the .pkg targetable has been exercised by me… Enjoy!


BASH parameter fun

Some exercises in handling parameters in a script:

Using BASH_ARGV to loop through all arguments

#debugging output
[ -f /tmp/debug ] && set -x

#Loop Though the arguments provided
#BASH places arguments in reverse order in BASH_ARGV array
#Start at end of array (ARGC – 1)
for (( i=$(( $BASH_ARGC – 1 )); i>=0; i– )); do
echo “\$$(( $BASH_ARGC – $i )): $item”

Loop through all arguments with special handling of first and last only

[ -f /tmp/debug ] && set -x
##loop through parameters, start with end of BASH_ARGV
for (( loopNumber=1, i=$(( $BASH_ARGC - 1 )); i>=0; i--, loopNumber++ )); do
#do something special for first and last
if [ $i -eq $(( $BASH_ARGC - 1 )) ]; then
conditionalString="(I am the first one!)"
elif [ $i -eq 0 ]; then
conditionalString="(I am the last one!)"
unset conditionalString
echo Arg $loopNumber: ${BASH_ARGV[$i]} $conditionalString

Loop through all arguments with special handling of first and everything else

[ -f /tmp/debug ] && set -x

##loop through parameters, start with end of BASH_ARGV
for (( loopNumber=1, i=$(( $BASH_ARGC – 1 )); i>=0; i–, loopNumber++ )); do

#if not the last don’t restart dock
if [ $i -eq $(( $BASH_ARGC – 1 )) ]; then
unset conditionalString
conditionalString=”(I am the first)”
conditionalString=”(I am not the first)”

echo Arg $loopNumber: ${BASH_ARGV[$i]} $conditionalString

Loop through all arguments with special handling of the last and everything else

[ -f /tmp/debug ] && set -x

##loop through parameters, start with end of BASH_ARGV
for (( loopNumber=1, i=$(( $BASH_ARGC – 1 )); i>=0; i–, loopNumber++ )); do

#if not the last don’t restart dock
if [ ! $i -eq 0 ]; then
conditionalString=”(I am not the last)”
unset conditionalString
#conditionalString=”(I am the last)”

echo Arg $loopNumber: ${BASH_ARGV[$i]} $conditionalString

(WordPress is bugging the heck out of me with the code tags breaking when their are line breaks… sorry, that’s an exercise for the Googler)

Downloading Safari 6

So when Safari 6 came out, Apple did away with download links from their Support site.
Why? Who knows. But it’s a real pain when you have børked install or install a Developer preview (which sometimes will not register in Software Updates and need to get up to the latest release.)

I contributed this tip to Apple Discussions in the HT5275 Safari 6 download thread and am reposting here as well since I repeatedly keep going back to get the command I authored! (No I don’t run Apple Software Update server, I have my own distribution methods for work that don’t involve merging software update catalogs and other ridiculous things OS X Server requires you to do if you dare run various OS X versions and don’t run the latest server). I parenthetically digress.

Here’s the Terminal command to spit out some Safari6 URLs (OS X 10.6-10.8):

curl -s $(strings /System/Library/PrivateFrameworks/SoftwareUpdate.framework/SoftwareUpdate | grep http | grep sucatalog) | grep Safari6 | grep pkg

It’ll give you something like this:

I know, not pretty right? But what you can do then is copy and paste the URL into Safari’s Address/Search bar and hit Option-Enter which will then download it.

Viola. A Safari 6 package.

Update for 10.9:
Now when you grep SoftwareUpdate there are multiple URLs for the seed programs, the easiest way to deal with this and still be generic is to loop through all the URLs grepping for Safari

for URL in $(strings /System/Library/PrivateFrameworks/SoftwareUpdate.framework/SoftwareUpdate | grep http | grep sucatalog); do curl -s "$URL" | grep Safari | grep pkg; done

XProtect Plugin Checker

Are you a system administrator or power user who needs a quick way to check if your Flash or Java plugins have been blocked by Apple? Like so:XProtectPluginChecker Menu 2

Then XProtectPluginChecker is the status menu app for you!

XProtect Plugin Checker iconClick to download.

Written in BASH, sprinkled with PlistBuddy/awk/sed-Fu with a dash of mdfind magic, and wrapped with Platypus, the aim is for XProtect Plugin Checker to be able to dynamically accommodate any additions Apple might make to the Plugin Blacklist, although only Flash and Java seem to be in their crosshairs right now, who knows? Silverlight might be next, given its lack of updates (going on 10 months).

A bonus idea for making this more useful is to make a launchd script that watches the XProtect plist file(s) then fires off the XProtectPluginChecker script when they change, emailing the results to you, because knowing is half the battle!

If you find this useful or if you have some hiccups with it, let me know. UPDATE: Now with comments enabled! :]

Also related, myXProtectStatus is a similar style menu status script that lists the malware threats Apple is blocking.

Check Multiple iMacs for 1TB Seagate Repair Program Eligibility

Apple recently announced that certain iMacs with 1TB Seagate hard drives are eligible for replacement. If you have one iMac it’s easy to check it on their website here.

However if you have a lot of iMacs at your company you might prefer to do this a bit more quickly! The following command can be sent via ARD:

curl  "$(ioreg -c "IOPlatformExpertDevice" | awk -F '"' '/IOPlatformSerialNumber/ {print $4}')" 2>/dev/null

To explain: It’s using curl to send a request to the Apple URL, the sn= field is populated with the results of the ioreg command, which is cleaned up with awk (thanks OS X Hints), stderr of curl is sent to /dev/null so you don’t get the download/progress output that curl usually displays.

Another variation is if you already have a list of serial numbers, separated with some sort of whitespace. You can put them in a bash variable and loop though them locally:


for number in $serialNumbers; do echo $number $(curl "$number" 2>/dev/null); done

This outputs the serial number queried and the response from the Apple server on each line. E03 the response you’ll be looking for. I’ll leave it to you the reader if you want to do any additional cleanup of the output, here’s a sample:

QP0231XXXPK iMacHDCheck.response({"ERROR_CODE":"E08","ERROR_DESC":"Valid iMac SN but WoM is outside of program range"})
QP0240XXXRU iMacHDCheck.response({"ERROR_CODE":"E03","ERROR_DESC":"Valid iMac SN has Seagate HDD - covered by program"})
D25FP1TXXXJT iMacHDCheck.response({"ERROR_CODE":"E07","ERROR_DESC":"Valid iMac SN with NO Seagate HDD"})
QP6481XXXUW iMacHDCheck.response({"ERROR_CODE":"E02","ERROR_DESC":"Serial ID is not iMac."})


Apple’s New Epoch Time for WebComponentsLastUsed

The latest Java update for Lion 2012-003 ( which after 3 revisions is still called JavaForOSX-1.0 in Software Update – oh, Apple! But I digress…) will turn off Java if it hasn’t been used in 30 days (or so I hear). It accomplishes this by writing a value to the WebComponentsLastUsed in ~/Library/Preferences/ByHost/

It used to be enough to have WebComponentsEnabled set to True, but now WebComponentsLastUsed is required or the unclickable “Plugin-Disabled” button will be shown in Safari’s lower right corner (it totally looks clickable yeah?)

If you work at a company that requires Java web components to be on for things like timesheets, making sure Java stays on helps to avoid getting help desk calls.

So I needed to figure out how this value was computed, it was too small to be the Unix epoch (seconds since January 1, 1970), so I did some sleuthing, some comparitive analysis (just to sound fancy), and figured out it is the number of seconds since January 1, 2001. To get this value you just need to get the Unix epoch and subtract the number of seconds since Jan 1, 2001.

Here’s the way to get this value in a BASH Terminal:

echo $(( $(date "+%s") - 978307200 ))

Toggling the check box in /Applications/Utilities/Java Preferences will reset the WebComponentsLastUsed value and you will find it very close to the value from Terminal.

Wasn’t that fun? The Der Flounder blog has a script using this method to turn on Java. He was a good sport to incorporate my code, too. He enlightened me with his UUID scripting code, so share and share alike, I say.

Bonus link for Apple’s other epoch time, for iTunes’ XML Play Date field: January 1, 1904 – that’s the first year of the last century with a leap year, so says Filemaker! ;)

Update / Create Lion RecoveryHD Partition Quickly Without Reinstalling

April 6, 2015 UpdatecreateRecoveryHDUpdater 15.4.6.command – built PKG now is targetable to volumes other than /

Feb 28, 2015 Update: New script on Software page and here:
createRecoveryHDUpdater 15.2.28.command

Apple released the Lion Recovery Update in October, 2011, and, after they updated the Lion recovery partition to 10.7.2, there was a great hint from Clay Caviness who dug into the update and highlighted the the relevant files and commands that it used to accomplish this update.

Recently, 10.7.3 came out, however, and the RecoveryHD partition is not updated if you use Software Update; it will stay at 10.7.2. This is probably not a big deal, as Apple didn’t deem it necessary to update, but for some users, this may not be good enough.

Note: Running the full 10.7.3 installer from the App Store will update the partition; this is fine for your home computer but not practical for large deployments.

Script Workflow:

  • Asks for locations of Recovery Update, Install OS X, and destination
  • Expands and collects the dmtest tool from the Lion Recovery Update
  • Collects the hidden Basesystem chunklist and dmg found in the InstallESD.dmg inside “Install Mac OS X”

The script making the Disk Image

  • Puts it all neatly into a self-contained disk image along with the script RecoveryHD Updater.command which can be used to easily create or update the RecoveryHD partition, even on the disk you are currently booted from; don’t worry dmtest takes care of all the logic to create or update.

The final disk image


  • Download the latest version of Install OS X Option-click the Purchases tab in the App Store and you will be able to “Install” (download) the latest version available
  • Download Lion Recovery Update from Apple

Script Tip:

Copy and paste the script into TextWrangler, save with a .command extension and it will automatically set the executable bit.

createRecoveryHDUpdater.command (downloadable script):


#this script will make a disk image with the tools needed to update your Recovery HD with the newest OS X Lion release

#Required components:
#Lion Recovery Update v1.0 -
#"Install Mac OS X" - App Store

# RecoveryHD Updater.command

#this script that will be saved to the disk image that is created
MYPATH="$(dirname "$0")"

#get destination drive
if [ "$1" == "" ]; then
echo -n "Please drag in DESTINATION disk for Recovery HD partition and press Enter: "
while [ -z "$DEST" ]; do
read DEST
if [ ! -d "$DEST" ]; then echo "$DEST not found"; exit; fi

#create Recovery partition
sudo "$MYPATH"/bin/dmtest ensureRecoveryPartition "$DEST" "$MYPATH"/etc/BaseSystem.dmg 0 0 "$MYPATH"/etc/BaseSystem.chunklist


#IMAGETEMP is the pathname for the disk image being built, will the OS and Build appended to the name later
IMAGETEMP="/tmp/Recovery HD Updater"

#temp folder for package expansion

#Mounted disk image paths
ESDPATH="/Volumes/Mac OS X Install ESD"
RECOVERYPATH="/Volumes/Mac OS X Lion Recovery HD Update"

#get Recovery Update dmg path
if [ "$1" == "" ]; then
echo -n "Please drag in RecoveryHDUpdate.dmg and press enter: "
while [ -z "$RECOVERYHDUPDATE" ]; do
if [ ! -f "$RECOVERYHDUPDATE" ]; then echo "$RECOVERYHDUPDATE not found"; exit; fi

#get Lion Installer path
if [ "$2" == "" ]; then
echo -n "Please drag in \"Install Mac OS X\" and press enter: "
while [ -z "$LION" ]; do
read LION
if [ ! -d "$LION" ]; then echo "$LION not found"; exit; fi

#get destination path for disk image to be created at
if [ "$3" == "" ]; then
echo -n "Please drag in Destination folder for disk image: "
while [ -z "$DEST" ]; do
read DEST
if [ ! -d "$DEST" ]; then echo "$DEST is not a valid path"; exit; fi

#mount Recovery Update image
hdiutil attach "$RECOVERYHDUPDATE"

#expand packge inside to temp folder (contains dmtest)
pkgutil --expand "$RECOVERYPATH"/RecoveryHDUpdate.pkg "$RECOVERY_EXPANDED"

#if we were using what's inside the chunklist and recovery inside the update we would mount this
#RecoveryHDMeta="/Volumes/Recovery HD Update"
#hdiutil attach "$RECOVERY_EXPANDED"/RecoveryHDUpdate.pkg/RecoveryHDMeta.dmg

#open Lion install ESD image for the newest files
hdiutil attach "$LION"/Contents/SharedSupport/InstallESD.dmg

#get OS version from Lion Installer ESD
OSVER=$(defaults read "$ESDPATH"/System/Library/CoreServices/SystemVersion ProductUserVisibleVersion)
OSBUILD=$(defaults read "$ESDPATH"/System/Library/CoreServices/SystemVersion ProductBuildVersion)

#append info to path so disk image volume name is informative and useful

#make work the folder
mkdir -p "$IMAGETEMP"/etc/
mkdir "$IMAGETEMP"/bin/

#copy dmtest to IMAGETEMP
if [ -f "$RECOVERY_EXPANDED"/RecoveryHDUpdate.pkg/Scripts/Tools/dmtest ]; then
cp "$RECOVERY_EXPANDED"/RecoveryHDUpdate.pkg/Scripts/Tools/dmtest "$IMAGETEMP"/bin/
echo "$RECOVERY_EXPANDED/RecoveryHDUpdate.pkg/Scripts/Tools/dmtest not found, exiting"
exit 1

#copy the BaseSystem dmg and chunklist to destination/etc
if [ -f "$ESDPATH"/BaseSystem.chunklist -o -f "$ESDPATH"/BaseSystem.dmg  ]; then
cp "$ESDPATH"/BaseSystem.chunklist "$ESDPATH"/BaseSystem.dmg "$IMAGETEMP"/etc/
#unhide BaseSystem
chflags -R nohidden "$IMAGETEMP"
echo "$ESDPATH/BaseSystem* not found, exiting"

#put script in folder root
echo "$RecoveryHDUpdaterScript" > "$IMAGETEMP"/"RecoveryHD Updater.command"
#set permissions
chmod ugo+x "$IMAGETEMP"/"RecoveryHD Updater.command"

#create disk image from folder
hdiutil create -srcfolder "$IMAGETEMP" "$DEST"/RecoveryHDUpdater_$OSVER_$OSBUILD.dmg
if [ $? -eq 0 ]; then
echo "Success! Created: $DEST/RecoveryHDUpdater_$OSVER_$OSBUILD.dmg"
echo "Now opening "$DEST"/RecoveryHDUpdater_$OSVER_$OSBUILD.dmg"
hdiutil attach "$DEST"/RecoveryHDUpdater_$OSVER_$OSBUILD.dmg
echo "Disk Image failed"

echo "Cleaning Up"
#delete temp folders

#eject the volumes
hdiutil eject "$RECOVERYPATH"
hdiutil eject "$ESDPATH"

echo "Done."


The script can also be run with command line arguments:

$ ./createRecoveryHDUpdater.command [Recovery Update DMG] [Install Lion App] [Destination for DMG]

As well as the script that is put in the created disk image:

$ ./RecoveryHD\ Updater.command [Destination]

Otherwise just double-click it in the Finder and it will ask you for the files and paths which you can just drag into the Terminal window and press Enter (don’t worry about the trailing spaces it adds)

When you run the script in the disk image you will be prompted for an admin password and away it goes, with all sorts of ugly output because it never thought a human would gaze upon it’s hidden ways…

dmtest updating the RecoveryHD partition


Update: Just tested with 10.7.4 and this script still works correctly, nothing has changed in the structure of the updated Install OS X from the App store, note that the 10.7.4 installer is version 1.0.21 (10.7.2=1.0.13 and 10.7.3=1.0.16)

Update: Script will work on 10.8 without modification, however I have updated the script anyway to be a bit quieter when mounting the various DMGs, to accept tilde paths, accept the RecoveryHDUpdater as either a DMG or PKG, and changed prompt phrasing to include Mountain Lion.

Getting and setting PPD options via command line for use with lpadmin in OS X

UPDATE – Script now will convert CR to LF line endings for better reliability with old PPDs

There are some good hints for adding printers via the command line with lpadmin: Managing multiple printers via the command line

However, there is still confusion surrounding the setting of printer options from the command line, as a poster to Debian bugs pointed out back in 2006: lpoptions documentation doesn’t. After doing some testing, here’s the two main takewaways:

  • If you use lpadmin and specify options with “-o” the PPD is altered and OS X will recognize the options for the printer.
  • However, if you setup the printer using lpadmin without any options and later use lptoptions to set the options, they are not written to the PPD and the GUI is unaware of the printer’s options.

more helpful hints about lpadmin and lpoptions:

lpoptions -p printername -l

  • Prints PPD options, “Default” is filtered out from option name (compared to looking at the raw PPD)
  • It uses a colon when reporting key value pairs, however replace that with an equals sign when specifying an option
  • The option name stops at the first slash
  • Example: The duplex option for HP printers will output like this “HPOption_Duplexer/Duplex Unit: *True False”
    When specified as a “-o” option it would be “HPOption_Duplexer=True”

lpadmin … -o this=that

    • Alters the ppd that is placed in /etc/cups/ppd/ when the printer is installed

Unhelpful things:

lpoptions -p printername

  • These are NOT the PPD options you want to set

lpoptions -o

  • Only writes options to: /private/etc/cups/lpoptions (run with sudo) or ~/.cups/lpoptions (run as current user), GUI apps are unaware of these options

The following script compares the original and the newly installed PPD to generate the options syntax to be used with lpadmin: 

The main magic in this script is a little diff and sed:

diff "$originalfile" "$newfile" | grep "> [*]Default" | sed 's/> [*]Default/-o /g' | sed 's/: /=/g'

Script Workflow

  • Copy and paste the script into TextWrangler (or download ppdOptionsDiff.command), save with a .command extension and it will automatically take care of the executable bit
  • Setup your printer via the Printers Preference Pane in the GUI.
  • Look in /etc/cups/ppd and find the newest .ppd (it will be named as the printer)
  • Locate the original .ppd.gz (or .ppd) in /Library/Printers/PPDs/Contents/Resources/, usually the printer ppd is easily found by name, but some like Canon have some cryptic filenames, so look inside the /etc/cup/ppd file, the “PCFileName” variable sometimes helps to determine the file name
  • Run the script given below, it will ask you to drag in the original and the modified ppds. Out will come the “-o” options for use with lpadmin

You can also run the script with the original and modified file paths as arguments and the string will be output

The script “ppdOptionsDiff.command“:

[ -f /tmp/debug ] && set -x
#ppd option maker

if [ “$1” == “-h” ]; then
echo “$(basename $0) compares two ppds and outputs the differences as a string for use in lpadmin”
echo “Usage: $(basename $0) [original_ppd] [new_ppd]”

#check for parameter if not ask
if [ -z “$1” -o -z “$2” ]; then
echo “Drag in the unmodified PPD from /Library/Printers/PPDs/Contents/Resources:”
open /Library/Printers/PPDs/Contents/Resources
while [ -z “$originalfile” ]; do
read originalfile

echo “Drag in the PPD from /etc/cups/ppd:”
open /etc/cups/ppd
while [ -z “$newfile” ]; do
read newfile
#else just take the arguments
elif [ -n “$1” -o -n “$2″ ]; then

#make a temp file of the original to compare
#strip off path and extension for temp file name
tempOriginalFile=”/tmp/$(basename “$originalfile” .gz)”

#if file is compressed expand
if [ “${originalfile##*.}” == “gz” ]; then
#gunzip to temp file
gunzip < “$originalfile” > “$tempOriginalFile”
#just make a copy
cp “$originalfile” “$tempOriginalFile”

#change line endings from CR to LF (diff fails unless this is done)
sed -e $’s/\\\r/\\\n/g’ -i ” “$tempOriginalFile”

#make a temp file of the new file to compare
#strip off path
tempNewFile=”/tmp/$(basename “$newfile”)”
cp “$newfile” “$tempNewFile”

#change line endings from CR to LF (diff fails unless this is done)
sed -e $’s/\\\r/\\\n/g’ -i ” “$tempNewFile”

#test for file existence
if [ ! -f “$tempOriginalFile” ]; then echo “$tempOriginalFile is not a valid path”; exit; fi
if [ ! -f “$tempNewFile” ]; then echo “$tempNewFile is not a valid path”; exit; fi

#create options list by diffing and filtering
optionList=$(diff “$tempOriginalFile” “$tempNewFile” | grep “> [*]Default” | sed ‘s/> [*]Default/-o /g’ | sed ‘s/: /=/g’)

#print out the options with no line breaks
if [ ! -z “$optionList” ]; then
for option in $optionList; do
echo -n “$option ”
echo No differences

#delete the temp filess
rm “$tempOriginalFile” “$tempNewFile”


Example (with pathnames provided as arguments, otherwise runs in interactive mode):

$ ./ppdOptionsDiff.command /Library/Printers/PPDs/Contents/Resources/HP\ LaserJet\ 5200.gz /private/etc/cups/ppd/PRINTERNAME.ppd

-o HPOption_Tray3=Tray3_500 -o HPCollateSupported=True -o HPOption_Duplexer=True -o HPOption_Disk=RAMDisk

Use the generated string in lpadmin to set the printer options.

Make a Snow Leopard 10.6.7 Installer Disc from a Mac Restore Disc

So there was this hint the other day at MacWorld’s OS X Hints site:
10.6: Make a universal 10.6.7 Snow Leopard installer – Mac OS X Hints

It was a very useful hint for hacking together a retail Snow Leopard disc (10.6.0/10.6.3 ) and the newest system specific restore disc (10.6.7 for iMacs and MacBook Pros) to make a “universal” 10.6.7 disc that would work on new and old machines alike, that are qualified to run Snow Leopard. Useful not only for techs who need a one disc does it allbut others who might lack bandwidth for updates since this cuts down on some Software Update downloads (10.6.8 is only a smaller “delta” update this way.)

So, it was a good hint because it got to the heart of the matter, that OSInstall.mpkg was where the script logic determines if your machine is qualified for the restore. However using the original 10.6 disc and copying over all the old printer drivers is a little too kludgy for me, the less donethe better. I knew there had to be a more elegant way…

Voila – this bash script strives for automagic: it reads in your restore disc, prompts you to grab your disc and pop in a blank DVD, then modifies the install logic, and burns the disc you can use on all your Snow Leopard elligible Macs (P.S. Don’t steal OS X). It hasn’t been QC’d or QA’d beyond a few runs using one set of 10.6.7 restore disc, but I hope it comes in handy for some Mac tech out there somewhere who is in a pinch and needs to restore Snow Leopard – if only to get App Store on a machine and then up to 10.7 or 10.8!



destination=~/Desktop/Mac\ OS\ X\ Install\ DVD

#make destination folder
[ ! -d "$destination" ] && mkdir "$destination"

#make sure disc is in drive
while [ ! -d /Volumes/Mac\ OS\ X\ Install\ DVD ] ; do
echo Please insert Mac OS X Install DVD and press Enter

#get device node for block copy
device=$(diskutil info /Volumes/Mac\ OS\ X\ Install\ DVD/ | grep Node | cut -f2 -d:)

#create disk image from device (retains Finder window custom background)
echo "Creating Disc image at $destination, please wait..."
/usr/bin/hdiutil create -srcdevice $device -format UDRW "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

#disk image using source folder (loses custom Finder background)
#/usr/bin/hdiutil create -srcfolder /Volumes/Mac\ OS\ X\ Install\ DVD/ -format UDRW "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

#eject media
/usr/bin/drutil eject

#tell user to take out disc
echo -e $'\a'$'\a'$'\a'$'\n'"Please Remove the disc and press Enter"$'\n'

echo "Modifying Image"
#mount r/w image
hdiutil attach "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

#expand OSINstall.mpkg
/usr/sbin/pkgutil --expand /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded

#modify Distribution script in place with no backup
/usr/bin/sed -i '' "s/modelProp\ \=\=\ hwbeSupportedMachines\[i\]/1/g" /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded/Distribution

#modify Distribution script in place with backup (for sissies)
#/usr/bin/sed -i '.original' "s/modelProp\ \=\=\ hwbeSupportedMachines\[i\]/1/g" /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded/Distribution

#remove original OSInstall.mpkg package
/bin/rm -rf /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg

#flatten new package
/usr/sbin/pkgutil --flatten /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.mpkg

#remove expanded folder
/bin/rm -rf /Volumes/Mac\ OS\ X\ Install\ DVD/System/Installation/Packages/OSInstall.expanded

### image is now ready to be burned ###

#eject disk image
hdiutil eject /Volumes/Mac\ OS\ X\ Install\ DVD/

#burn disc image
/usr/bin/drutil burn "$destination"/Mac\ OS\ X\ Install\ DVD.dmg

echo -e $'\a'$'\a'$'\a'$'\n'"Disc Complete, Please Remove the disc"$'\n'