#列出所有限制的配置
ulimit -a
#如下：
core file size (blocks, -c) 0 #0为不限制
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 20
file size (blocks, -f) 1024
pending signals (-i) 16382
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024 #限制打开的文件
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) unlimited
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
#括号中都有-f 之类的，可以通过这种参数修改
#例如修改限制用户仅能创建10M的文件
ulimit -f 10240
