Launchd and Pathstate errors

Question

Hi,
I've been playing around with launchd but I end up getting some errors when I use the pathstate parameter. This is my plist :
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Debug</key>
<true/>
<key>Label</key>
<string>com.test.hourly</string>
<key>KeepAlive</key>
<dict>
<key>PathState</key>
<dict>
<key>/Users/Shared/Nas/test</key>
<true/>
</dict>
</dict>
<key>LowPriorityIO</key>
<true/>
<key>Nice</key>
<integer>1</integer>
<key>Program</key>
<string>/Users/Shared/Local/scripts/test.sh</string>
<key>ServiceDescription</key>
<string>hourly test</string>
<key>StartCalendarInterval</key>
<array>
<dict>
<key>Minute</key>
<integer>12</integer>
</dict>
<dict>
<key>Minute</key>
<integer>14</integer>
</dict>
<dict>
<key>Minute</key>
<integer>16</integer>
</dict>
<dict>
<key>minute</key>
<integer>18</integer>
</dict>
</array>
</dict>
</plist>
And in the console I get :
28/11/2009 15:55:14 com.apple.launchd.peruser.501[185] (com.test.hourly) Bug: launchdcorelogic.c:4562 (23932):2
This error goes away if I remove the pathstate from my plist. Any ideas on how to fix this? This is on 10.6.2 and it's stored in ~/Library/LaunchAgents.
I'm basically trying to see if my macbook is at home and can see my nas before running a backup script. Any help would be greatly appreciated. Thanks.
A

Answer 1

shopperboy wrote:
Is there a way to get launchd to do both?
The best way to think of launchd is as a triggering mechanism: it waits for a particular set of conditions to arise, and then fires off the script it's told to run. it doesn't really have the capacity to check for negative (not) conditions in any sophisticated way, and its capacity for running scripts internally is limited. the only way to do what you're asking (that I know of) would be to write a second launchd job whose job it is to check whether that particular path exists and enables/disables the first launchd plist, which seems like more trouble than it's worth.
having the job triggered when the network storage is offline won't use any significant system resources, though I do understand that it's not as elegant as one might like...