Quickly Calculate size of radmind Transcript Payload

grep ^[af] /var/radmind/transcript/transcript_name.T | awk ‘{sum = sum + $7} END {print sum/1000}’

Every line that starts with “a” or “f” is a file. Sum up the size field. Divide by 1000 to get KB.


Prevent a launchd job from rerunning until existing job finishes

I often need to schedule scripts to run at an interval, but I don’t know how long that script will take to complete and I don’t want the script to run again at its normal interval unless the script isn’t running.

I’ve done this with pid files and grepping through ps lists to exit the script if another instance is running, but I was wondering if there is something built into launchd to handle this.

It turns out that launchd does this by default. Just set up your job as normal using StartInterval and if your job hasn’t finished running by the next time it is scheduled to run, launchd will wait until the job finishes. If more than one schedule has passed, the missed jobs will be coalesced into one instance and run just once until the next scheduled run, much like it behaves if the machine goes to sleep.

Another win for launchd.

Simple AFP Forensics using Access Logs

Mac OS X Server’s AFP server access logs aren’t the greatest (no full paths is a glaring omission), but if you have them enabled, they can be useful for finding who deleted a file or folder for example.

If the item’s name starts with “Important File”, this command gives us the ip address of the client that deleted the item :
file_server:~ root# grep -i "Delete Important File*" /Library/Logs/AppleFileService/AppleFileServiceAccess.log
IP - - [08/Jul/2008:14:26:14 -0500] "Delete Important File 2009.xls" 0 0 0

Then we pass the ip address into this command to give us the login of the user:
file_server:~ root# grep /Library/Logs/AppleFileService/AppleFileServiceAccess.log | grep Login
IP - - [08/Jul/2008:09:05:43 -0500] "Login mpickens" 0 0 0

Finally we can use dscl to lookup the full name the user:
file_server:~ root# dscl localhost read /Search/Users/mpickens RealName
RealName: Pickens, Mary Ellen

Older logs are available too in zipped form. Use gunzip -c to read the contents.
file_server:~ root# gunzip -c '/Library/Logs/AppleFileService/AppleFileServiceAccess.log 12.11.07.gz' | grep Login | grep mpickens
IP - - [14/Dec/2007:19:12:38 -0500] "Login mpickens" 0 0 0
IP - - [14/Dec/2007:19:24:32 -0500] "Login mpickens" 0 0 0
IP - - [17/Dec/2007:09:21:38 -0500] "Login mpickens" 0 0 0
IP - - [17/Dec/2007:10:37:49 -0500] "Login mpickens" 0 0 0

convert lines to comma separated items with tr

If you have output that is separated by new lines, but you really want it formatted into a single line with commas as separators or maybe a space as a separator, just pipe to tr.

Here is a simple example:

kserver:~ patternbuffer$ diskutil list | grep ^/dev

If we want them separated by spaces, we could do:

kserver:~ patternbuffer$ diskutil list | grep ^/dev | tr '\n' ' '
/dev/disk0 /dev/disk1

Note that there is a newline on the end of the output, so that trailing newline is also translated. So if you don’t want it there, you’ll have to chomp it off. I use sed, but use what you like.

Here is the same as above, but with commas, with sed to remove the trailing comma.

kserver:~ patternbuffer$ diskutil list | grep ^/dev | tr '\n' ',' | sed 's/.$//'