su - make the shell a login shell

今天用oracle user执行命令时，出现线面的错误：

ERROR:

ORA-01031: insufficient privileges

SP2-0640: Not connected

All indexes are rebuilt.

经人指点，原来问题出在su

su manual --- http://www.delorie.com/gnu/docs/sh-utils/sh-utils_72.html
NAME

su - run a shell with substitute user and group IDs

SYNOPSIS

su [OPTION]... [-] [USER [ARG]...]

DESCRIPTION

Change the effective user id and group id to that of USER.

By default,

su

does not change the current directory.
It sets the environment variables

HOME

and

SHELL

from the password entry for user
, and if user
is not
the super-user, sets

USER

and

LOGNAME

to user
.
By default, the shell is not a login shell.

-

-l

--login

Make the shell a login shell
.  This means the following.  Unset all

environment variables except `TERM', `HOME', and `SHELL' (which

are set as described above), and `USER' and `LOGNAME' (which are

set, even for the super-user, as described above), and set `PATH'

to a compiled-in default value.  Change to USER's home directory.

Prepend `-' to the shell's name, intended to make it read its

login startup file(s).

原来是需要su - oracle，而不能用su oracle