最终确定是shell环境问题，临时改为/bin/bash即可查看.
1.问题现象
# su - jingyu
$ id
uid=(jingyu) gid=(jingyu) groups=(jingyu)
$ ulimit -a
ulimit: Command not found.
2.临时切换为/bin/bash即可查看
$ echo $SHELL
/bin/csh
$ bash
$ ulimit -a
core file size (blocks, -c)
data seg size (kbytes, -d) unlimited
scheduling priority (-e)
file size (blocks, -f) unlimited
pending signals (-i)
max locked memory (kbytes, -l)
max memory size (kbytes, -m) unlimited
open files (-n)
pipe size ( bytes, -p)
POSIX message queues (bytes, -q)
real-time priority (-r)
stack size (kbytes, -s)
cpu time (seconds, -t) unlimited
max user processes (-u)
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
$