Erik’s Lab

Just a quick tip: Repairing the permissions on an OS X disk can be done from the command-line as well. The only caveat, you have to know the device of the volume. Getting the right device is easy:

diskutil list

The device-node in question is in the column titled IDENTIFIER. The device-path to use is the one with the name of the volume, e.g. if the column reads disk0s2, then the command would be:

diskutil repairPermissions /dev/disk0s2

You should see some kind of progress-bar in ASCII.

One thing to note though: Using the command does not prevent the “meditation” of the program after 20%. I’d be interested what the system is doing while it seems to mull over something when it is supposed to repair the permissions.

Just a quick hint for all the commandline-jockeys: The standard-encoding for new MySQL-Databases on OS X Server 10.5.X is not UTF-8 but latin1.

Do not forget to specify the encoding when creating a new database, seriously. I suspect, that this depends on the language the system is installed in. The system that tricked me was using english, naturally. It didn’t help much, that WordPress thought writing to a databases using UTF-8 encoding. Everything worked fine until I dumped the database and restored it on another system.

Alternatively, there is no my.cnf in the standard-locations on a clean OS X Server 10.5.X install, create one and specify the right encoding there. But get in the habit of checking the current default encoding before creating a new database.

Just a quick FYI.

Everybody fantasized, hoped, longed, [you get the picture] about it: the Leopard 10.5.2 Update is soon to be found on Macs wide and far.

No problems so far, none I’m aware of, at least. Don’t forget to repair the permissions before and after the install, though. Seriously. And if you happen to have a recent digital camera in your bag, one of those to be precise:

• Canon EOS 1Ds Mark III
• Canon Powershot G9
• Hasselblad CF-22
• Hasselblad CF-39
• Leaf Aptus 75s
• Nikon D3
• Nikon D300
• Sony Alpha DSLR-A700

Then messing up the pictures in RAW is at your disposal.

Just in case you managed to miss the news.

This short how-to explains how you calculate with time- and date-values in AppleScript. Quite a few people told me, that they are using the do shell script-handler presented in the post How to convert an “epoch”-time to a meaningful date and time. Nothing wrong with that, but if you just want to perform time-calculations inside an AppleScript, then there is an easier way.

If you assign the current time to a variable as in set myDate to current date and you just want to calculate the current date plus 2 days, then there is no need to use epoch-seconds.

1. set myNewDate to myDate + (2 * days), adds 2 days to the date and time stored in myDate.
2. set myNewDate to myDate + (4 * hours), adds 4 hours to the current time and date.
3. set myNewDate to myDate + (30 * minutes), adds 30 minutes to the current time and date.

It is really that simple, AppleScript uses epoch-seconds to perform these calculations, so you don’t have to.

If you need to set the date and time to the beginning of the current day, then use

set myTime to time of myDate

set myNewDate to myDate - myTime

The variable myNewDate now contains the current date and 00:00:00 as time.

Epoch-seconds are great if you want to store a date-value and read it back in later, but as long as you stay inside an AppleScript, there is no need to resort to epoch-values.

Everyone agrees, that Time Machine makes your life a lot easier. Did you know about the fact, that programmers are able to integrate it into their applications?

For example, open iCal and click on Time Machine in the Dock. Now you are able to move back in time and restore deleted or changed entries. Sneaky.

But the fun does not stop here, you are able to restore mailboxes as well. The mechanism does not work with RSS-Feeds in Mail, though.