ps snippets

Track memory usage

ps axv --sort -rss

Select process by command name

ps -C <command_name>

Check PGID of processes

ps axfj

Turn off headers

ps h

more portable:

ps --no-headers

Total-up RSS usage

$  ps hax -o rss|paste -sd+|bc
5696576

$ free
             total       used       free     shared    buffers     cached
Mem:       8176380    7975948     200432     118576     125520    2147352
-/+ buffers/cache:    5703076    2473304
Swap:      4199420      54288    4145132