1. How to find files by content

$ find "main(" string in *.c file of current path
$ find . -name "*.c" -print | xargs grep "main("

2. Check process memory status

$ top 					#using top to get process id
$ cat /proc/70/status	#70 is the process id
$ watch -n 10 cat /proc/70/status #check process memory status per 10s

3. Iterate all PID

$ for pid in `ps -ef | grep your_search_term | awk '{print $2}'` ; do kill $pid ; done

Refer : http://stackoverflow.com/questions/21470362/find-the-pids-of-running-processes-and-store-as-an-array

Just replace your_search_term with the process name you want to kill.

You could also make it into a script and swap your_search_term for $1

EDIT: I suppose I should explain how this works.

The back ticks `` collects the output from the expression inside it. In this case it will return a list of pids for a process name.

Using a for loop we can iterate through each pid and kill the process.

EDIT2: replaced kill -9 with kill