Understanding the Parameter for ulimit in a glance on CentOS

If you need to look and understand the parameters of the ulimit. Just use the command

# 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) 311296
max locked memory       (kbytes, -l) unlimited
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) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 311296
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Look at the output and you will see that the parameter are within the ()

For example, if you wish to tweak the max locked memory to be unlimited, you can use -l

# ulimit -l unlimited 

Or

For example if you wish to  tweak the core file size to be unlimited, you can use -c

# ulimit -c unlimited