Mac Stuff

On a single Mac it’s a simple thing to set which time server your machine gets its time from. Simple go to System Preferences, click on “Date & Time” and enter the address for your preferred time server in the “set date & time automatically” box.

However, if you want to blow that setting out to multiple machines what do you do? The file that holds this setting is located in the /etc directory and is named ntp.conf.

Copy that file to the /etc directory on all your machines using something like Apple Remote Desktop and you’re done!

Just make sure the permissions match so the machine can read it correctly. The permissions should look like this:

-rw-r--r-- 1 root wheel 47 Apr 25 09:35 ntp.conf

admin :: Apr.25.2007 :: Management, System :: Comments Off on Setting the time server for multiple machines

Using the Printer Setup Utility in OS X is a very easy and simple way to create printers on a Mac. But occasionally you might have need to create printers at the command line. For example, you might want to create printers on remote machines that only have shell access. Or you might want to add the ability to create printers to a login script or a script that runs after a machine is re-imaged.

Well, the command to do this is lpadmin. lpadmin is used mainly to set up network printers. It’s the command line utility for CUPS, the underlying printing architecture of OS X. As usual you can type man lpadmin to get all the gory details. In this post I’m going to cover how to create a printer and how to delete one using Terminal and lpd.

Creating a new printer

The syntax to create a new printer is:

/usr/sbin/lpadmin -p "name of printer" -E -v lpd://"printer IP or DNS"/"queue name" -P "path to PPD file" -D "description"

The name of the printer is whatever you want the user to see, such as “color laser printer”. Just remember if your name has spaces in it you’ll either need to escape the spaces or quote the name. Also, the name cannot contain any non-printable characters (ex. % $ &). The description field, however, can. If you use the description field that is the name that appears in Printer Setup Utility. If you don’t then the name given in the - p flag will be the name.

All of the standard PPD files on a Mac are kept in /Library/Printers/PPD/Contents/Resources/en.lprog/. The actual PPD file will be contained in a .gz file. You just need to point to that file.

So, for our example we’ll set up a printer with the following attributes:

Name: Color_Laser
Type: HP Color Laser 4700
Print server: print.example.com
print queue: color_laser
description: Color Laser (Front Office)

So our command in the Terminal would be this:

usr/sbin/lpadmin -p Color_Laser -E -v lpd://print.example.com/color_laser -P /Library/Printers/PPDs/Contents/Resources/en.lproj/HP\ Color\ LaserJet\ 4700.gz -D "Color Laser (Front Office)"

Note that I quoted the “Color Laser (Front Office)” part to get around spaces in the name. That’s the name that appears in Printer Setup Utility.

Deleting a Printer

Deleting a printer is much easier. All you need is the name.

The syntax to delete a printer is:

/usr/sbin/lpadmin -x "name of printer"

If I wanted to delete the printer I just created all I would need to do is this:

/usr/sbin/lpadmin -x "Color Laser"

Note: The name you’re deleting is the name you gave it in the - p flag, not the description. So putting “Color Laser (Front Office)” in this would not work.

If you’ve forgotten what names you gave the printers open up a web browser on your machine and enter “http://127.0.0.1:631/printers”. That will take you to the configuration page for CUPS, which will list the printers by name.

Creating printers in AppleScript

You can wrap all of these commands up in an AppleScript and send it to users so they can install printers with just a click. Just wrap the commands in a do shell script command.

The one gotcha is because you are using quotes in the Terminal command AND you have to quote to actual command in AppleScript you have to escape the internal quotes by putting a “\” before each quote. You also have to escape and “escapes” you had in the original command.

To compare, here is the original command:

/usr/sbin/lpadmin -p "Color_Laser" -E -v lpd://print.example.com/color_laser -P /Library/Printers/PPDs/Contents/Resources/en.lproj/HP\ Color\ LaserJet\ 4700.gz -D "Color Laser (Front Office)"

And here is the command with the “do shell script” command in AppleScript:

[codesyntax lang=”applescript” lines=”no”]do shell script “/usr/sbin/lpadmin -p Color_Laser -E -v lpd://print.example.com/color_laser -P /Library/Printers/PPDs/Contents/Resources/en.lproj/HP\\ Color\\ LaserJet\\ 4700.gz -D \”Color Laser (Front Office)\””[/codesyntax]

admin :: Apr.20.2007 :: Applescript, Management, Scripts, shell scripts, Terminal :: 2 Comments »

I just had a need to write a quick script that told me what the color space of an image was (RGB, CMYK, Gray, etc.). So obviously I turned to AppleScript. AppleScript has a nice Scripting Addition called Image Events that can read lots of different information about an image. You can get all the details on the Image Events addition as well as some good examples here.

The one problem I found with Image Events was that it gagged whenever it looked at a grayscale image. No idea why. But, after doing some more research I found that Image Events is based on a UNIX command line tool named sips. Using sips and the AppleScript do shell script command I was able to get the information I needed.

For my immediate purposes I just wanted a script I could run, select a file and get the color information. So that’s what this script does.

[codesyntax lang=”applescript” lines=”no”]
set theFile to (quoted form of the POSIX path of (choose file))
set theColorSpace to (do shell script “sips -g space ” & theFile)
set oldDelims to AppleScript’s text item delimiters
try
set AppleScript’s text item delimiters to “:”
set theColor to text item 2 of theColorSpace as text
set AppleScript’s text item delimiters to oldDelims
on error
set AppleScript’s text item delimiters to oldDelims
end try
display dialog “The color space is: ” & theColor[/codesyntax]

Notice I had to set the file path to the POSIX path of the file. The POSIX path is the actual Unix style path name (ex. /Users/joe/image.jpg). I also had to use the quoted form part of AppleScript to deal with any spaces that might be in the file names. Running this will give you a dialog box with the name of the color space for this file.

Since Image Events can get lots of other bits of information and it’s easier to manipulate then having to parse. So, I combined AppleScript and Automator to make a Finder plug-in. I developed this Automator script to display the image’s size in pixels, resolution, color space and width in picas. It’s being used by a publisher here to quickly check sizes of images to make sure they meet certain requirements. I expect I’ll be adding things and tweaking it as I go.

Click on Image Info Automator workflow to download the workflow. Save it out as a Finder plug-in to use with any selected images.

admin :: Apr.12.2007 :: Applescript, Automator, Scripts :: Comments Off on Finding an image’s color space using AppleScript