Original @ http://acupof.blogspot.com/2010/06/process-heap-eden-tenured-and-permgen.html

public class J {

public static void main(String[] args) {

}

}


...
$ javac J
error: Class names, 'J', are only accepted if annotation processing is explicitly requested
1 error

sudo lsof -i TCP:8181 | grep LISTEN
java 1400 m...y 216u IPv6 0x...e5 0t0 TCP *:8181 (LISTEN)

grep -roh aaa . | wc -w
Grep recursively all files and directories in the current dir searching for aaa, and output only the matches, not the entire line. Then, just use wc to count how many words are there.
took from s.o. http://stackoverflow.com/a/6135712