Question: Is there any way to tell whether a particular application running on Mac OSX (10.2+) has some of its memory swapped out (i.e., to one of the `/private/var/vm/swapfile*` files)? And how much?

**Bounty (150 rps)**

Simple question. The first correct answer will be accepted if I see it with less than 2 days of expiration of the bounty period. If I still haven't got one then, I'll award it to whoever tells me the most interesting new fact. And if I didn't learn a single thing from any of the answers, I'll award the bounty to whoever writes most prettily.

Answer: 
Based on the ideas posted here I created this little line of code:

```
sudo vmmap notifyd | grep -A3 'Summary'

```

which displays the Summary section (3 lines) of the vmmap output. I've used `notifyd` in this example, but you can replace that with any PID you know of.

This line will try to list all Summary lines of all running processes. Obviously some will fail because their process id is already gone (process ended), but in general i found this is a great way to scroll through a list of memory information and spot the top swapper.

```
ps -o pid= -xa | awk '{print $1}' | xargs -n 1 sudo vmmap | grep -A3 'Summary'

```

Edited: Some anonymous user saw this last command line needed an improvement because obviously the original variant did not work anymore. So thank you very much whoever you are and i'm sorry your edit was rejected. (First command previously read 'ps xa' and resulted in vmmap to fail because of the headline of ps being thrown at it)

Further improvement: If you like to know the name of the program right away use this small change

```
ps -o pid= -xa | awk '{print $1}' | xargs -n 1 sudo vmmap | egrep 'swapped_out|Path'

```

A little amendment on the other end of this command enables you to filter for certain program names or command line path components. Here we're looking at all processes from 'Library/PrivateFrameworks' only for example.

```
ps -o pid,command= -xa | grep 'Library/PrivateFrameworks' | awk '{print $1}' | xargs -n 1 sudo vmmap |

```
As ridogi said, open Activity Monitor. Navigate to the process you want to inspect, and click... Inspect! Then click memory; this will tell you how much swap the given process is using.

Have fun!