ulimit

ulimit command allow you to view or set user limits.

boby@sok-01:~$ ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 31482
max locked memory       (kbytes, -l) 16384
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 31482
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
boby@sok-01:~$ 

To increase limits for a user, edit file

vi /etc/security/limits.conf

Add

USER_NAME_HERE        hard nofile 20480
USER_NAME_HERE        soft nofile 10240