Identifying which processes are using network ports on a Mac

Typically I’d use netstat’s -o flag to identify the process ID when listing networking activity from a Linux/Unix machine. Unfortunately this option is not available with netstat on  Mac OS X.
I recently has a rogue process (I suspected a virus) on my Mac that was creating thousands of connections out to hosting providers. Luckily I [...]

Count the processors on a Linux server

If you need to see how many processors there are available on a Linu/Unix server, use the following command from your shell:
cat /proc/cpuinfo | grep processor
each of the processors will be listed in the output. For example, on a server I use the output looks like this:

processor : 0
processor [...]

Deleting all files over a certain age on a Linux server

To delete files on a Linux server that are all over 3 days old, use this:

find /log/ -type f -mtime -3 -exec rm {} \;

This command will find all files in /log over 3 days old and will run the rm command for each of them.