New answer, powershell

TCP

Get-Process -Id (Get-NetTCPConnection -LocalPort YourPortNumberHere).OwningProcess

UDP

Get-Process -Id (Get-NetUDPEndpoint -LocalPort YourPortNumberHere).OwningProcess

Old answer, cmd

 C:\> netstat -a -b

(Add -n to stop it trying to resolve hostnames, which will make it a lot faster.)

Note Dane's recommendation for TCPView. It looks very useful!

-a Displays all connections and listening ports.

-b Displays the executable involved in creating each connection or listening port. In some cases well-known executables host multiple independent components, and in these cases the sequence of components involved in creating the connection or listening port is displayed. In this case the executable name is in [] at the bottom, on top is the component it called, and so forth until TCP/IP was reached. Note that this option can be time-consuming and will fail unless you have sufficient permissions.

-n Displays addresses and port numbers in numerical form.

-o Displays the owning process ID associated with each connection.

Bruno is right on track. I've done extensive research and if you want to set variables that are available in all GUI applications, your only option is /etc/launchd.conf.

Please note that environment.plist does not work for applications launched via Spotlight. This is documented by Steve Sexton here.

1. Open a terminal prompt

2. Type sudo vi /etc/launchd.conf (note: this file might not yet exist)

3. Put contents like the following into the file

   # Set environment variables here so they are available globally to all apps
   # (and Terminal), including those launched via Spotlight.
   #
   # After editing this file run the following command from the terminal to update
   # environment variables globally without needing to reboot.
   # NOTE: You will still need to restart the relevant application (including
   # Terminal) to pick up the changes!
   # grep -E "^setenv" /etc/launchd.conf | xargs -t -L 1 launchctl
   #
   # See http://www.digitaledgesw.com/node/31
   # and http://stackoverflow.com/questions/135688/setting-environment-variables-in-os-x/
   #
   # Note that you must hardcode the paths below, don't use environment variables.
   # You also need to surround multiple values in quotes, see MAVEN_OPTS example below.
   #
   setenv JAVA_VERSION 1.6
   setenv JAVA_HOME /System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home
   setenv GROOVY_HOME /Applications/Dev/groovy
   setenv GRAILS_HOME /Applications/Dev/grails
   setenv NEXUS_HOME /Applications/Dev/nexus/nexus-webapp
   setenv JRUBY_HOME /Applications/Dev/jruby
   
   setenv ANT_HOME /Applications/Dev/apache-ant
   setenv ANT_OPTS -Xmx512M
   
   setenv MAVEN_OPTS "-Xmx1024M -XX:MaxPermSize=512m"
   setenv M2_HOME /Applications/Dev/apache-maven
   
   setenv JMETER_HOME /Applications/Dev/jakarta-jmeter
   

4. Save your changes in vi and reboot your Mac. Or use the grep/xargs command which is shown in the code comment above.

5. Prove that your variables are working by opening a Terminal window and typing export and you should see your new variables. These will also be available in IntelliJ IDEA and other GUI applications you launch via Spotlight.