ps ax | grep post
 3080 ?        Ss     0:00 /usr/lib/postfix/master
 3318 ?        Ss     0:01 /usr/bin/postmaster -D /psgql/data
 3319 ?        Ss     0:01 postgres: logger process
 3321 ?        Ss     0:10 postgres: writer process
 3322 ?        Ss     0:06 postgres: wal writer process
 3323 ?        Ss     0:02 postgres: autovacuum launcher process
 3324 ?        Ss     0:02 postgres: stats collector process
13921 tty2     S+     0:00 grep post