How to monitor contents of sub-folders in a Folder Action?

Question

Hello. I am wondering how I might read a folder's contentModDate within Terminal, i.e. from the command line and/or within a Folder Action.
This is the situation: I am running Periscope Pro (PP) for motion-detected videos, which by default, places them within the user's ~/Movies/com.zipzapmac.Periscope-Pro folder. Within that folder, PP creates a folder with it's name based upon (a) machine name and (b) primary MAC address. For example, we'll pretend this folder is called MacPro(001122334455). Then within that folder, as PP is running in motion-detection mode, it creates a new folder based on the current date and then, within that, places videos when motion is detected. Very straight-forward and it works just fine.
What I would like to do is have a folder action that (a) detects when any new folder or file is created within MacPro(001122334455) and (b) sends me a text-message via Apple Mail.
If the MacPro(001122334455) folder is empty, I can create a Folder Action that will detect the creation of a sub-folder when the first motion-detected video is created and that successfully sends me a text-message, BUT if a second video is created later within the same date-named folder, I will not get a message. I would get a text-message on the following day as a new folder is created within MacPro(001122334455) that signals the first motion-detected video of the day, but again not subsequent videos on the same day.
The text-message via Apple Mail I have easily scripted via Applescript and it works flawlessly.
Since Folder Actions only work upon a single pre-defined folder and not on sub-folders, I can never get automatically notified via text-message of second/third/fourth/etc. motion-detected videos as they're created... only the first one of each day.
So, I'm wondering whether there's a different way, perhaps through launchd that I might script this process. I'm thinking that if the contentModDate value of the MacPro(001122334455) folder could be read, compared with the last known value, and then---if different---execute the Applescript. OR PERHAPS I'm going about this all wrong and you might have another, better idea?
I'm open to suggestions.
-- David (da2357)

Answer 1

Well, I found a solution that does not use a Folder Action. Since Folder Actions will only work upon the specified folder and not upon the contents of any sub-folders, I needed a different solution.
First, I launched Terminal and created a new file called monitorPeriscope. I set executable permissions (chmod 700 monitorPeriscope). The contents of the file:
#!/bin/bash
# monitor the size of a specified folder and
# when the size increases, run an applescript
# copyright 2013, david dot allie at me dot com
# you are welcome to use this script, but please attribute authorship.
# CONSTANTS
WATCHFOLDER="/users/xadmin/movies/com.zipzapmac.Periscope-Pro"
SIZEFILEONE="/users/xadmin/.bin/foldersizeone"
SIZEFILETWO="/users/xadmin/.bin/foldersizetwo"
MYAPPLESCRIPT="/users/xadmin/documents/dropbox/programming/applescript/motion_de tected_text.scpt"
# START
# calculates current size of watchfolder, saves to sizefiletwo, then
# performs a diff operation, result which is evaluated in if statement,
# and if different, runs applescript, and copy sizefiletwo to sizefileone
du -h -k -d3 -c $WATCHFOLDER | awk 'END{print}' | awk '{print $1}' > $SIZEFILETWO
diff --brief $SIZEFILEONE $SIZEFILETWO
if [ $? -eq 1 ]
  then
    osascript $MYAPPLESCRIPT
    cp -f $SIZEFILETWO $SIZEFILEONE
fi
exit 0
Next, I created the following Applescript, replacing Some User, [email protected] and the text address of [email protected] below with my real values.
using terms from application "Mail"
tell application "Mail"
set theName to "Some User"
set theAddress to "[email protected]"
set theContent to "Motion detected in OFFICE."
set newMessage to make new outgoing message
tell newMessage
make new to recipient at end of to recipients with properties {name:theName, address:theAddress}
set visible to true
set sender to "[email protected]"
set subject to "ALERT "
set content to theContent
send newMessage
end tell
end tell
end using terms from
Next, using the touch command, I created /users/xadmin/.bin/foldersizetwo and /users/xadmin/.bin/foldersizetwo as needed for the bash shell script (touch /users/xadmin/.bin/foldersizeone and touch /users/xadmin/.bin/foldersizetwo).
Next, still in Terminal, I navigated to ~/Library/LaunchAgents and created the following plist using nano, which I named com.xadmin.monitorPeriscope.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>Disabled</key>
          <false/>
          <key>Label</key>
          <string>com.xadmin.monitorPeriscope</string>
          <key>ProgramArguments</key>
          <array>
          <string>/users/xadmin/.bin/monitorPeriscope</string>
          </array>
          <key>RunAtLoad</key>
          <true/>
          <key>StartInterval</key>
          <integer>900</integer>
</dict>
</plist>
Finally, all that was needed was to log out and then log back in. Once I launched the Periscope Pro app and started the motion-detection mode, I left my office... and within fifteen minutes I received a text message indicating that motion had been detected in my office. In the plist above, I set a StartInterval of 900 seconds, which corresponds to 15 minutes. I can reduce it down to 300 seconds (5 minutes) without it adversely affecting performance, but I'm going to leave the setting where it is for now.
So, I solved my own problem and I'm pleased with the results.
-- David