[yz@localhost ~]$ ps ux | grep postgresql
yz        1612  0.0  0.0 112728   996 pts/2    S+   15:39   0:00 grep --color=auto postgresql
yz       17442  0.0  0.1 272944 13308 ?        Ss   01:16   0:01 /home/yz/postgresql/pg_bin/bin/postgres -D /home/yz/postgresql/pg_data

[yz@localhost ~]$ lsof -p 17442
COMMAND    PID USER   FD   TYPE             DEVICE  SIZE/OFF      NODE NAME
postgres 17442   yz  cwd    DIR              253,2      4096 268882575 /home/yz/postgresql/pg_data
postgres 17442   yz  rtd    DIR              253,0       244        64 /
postgres 17442   yz  txt    REG              253,2  51299336 135847173 /home/yz/postgresql/pg_bin/bin/postgres
postgres 17442   yz  mem    REG              253,0     61624  33644885 /usr/lib64/libnss_files-2.17.so
……