RHEL6 某业务用户ulimit -a命令找不到

# su - jingyu
$ id
uid=503(jingyu) gid=507(jingyu) groups=507(jingyu)
$ ulimit -a
ulimit: Command not found.

$ 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
$