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=503(jingyu) gid=507(jingyu) groups=507(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) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 15978 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 102400 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) 15978 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited $