Provided by: login_4.0.13-7ubuntu3_i386
su - change user ID or become super-user
su [-] [username [ args ]]
su is used to become another user during a login session. Invoked
without a username, su defaults to becoming the super user. The
optional argument - may be used to provide an environment similar to
what the user would expect had the user logged in directly.
Additional arguments may be provided after the username, in which case
they are supplied to the user´s login shell. In particular, an argument
of -c will cause the next argument to be treated as a command by most
command interpreters. The command will be executed by the shell
specified in /etc/passwd for the target user.
The user will be prompted for a password, if appropriate. Invalid
passwords will produce an error message. All attempts, both valid and
invalid, are logged to detect abuses of the system.
The current environment is passed to the new shell. The value of $PATH
is reset to /bin:/usr/bin for normal users, or
/sbin:/bin:/usr/sbin:/usr/bin for the super user. This may be changed
with the ENV_PATH and ENV_SUPATH definitions in /etc/login.defs.
A subsystem login is indicated by the presence of a "*" as the first
character of the login shell. The given home directory will be used as
the root of a new file system which the user is actually logged into.
This version of su has many compilation options, only some of which may
be in use at any particular site.
user account information
secure user account information
login(1), login.defs(5), sh(1), suauth(5).
Julianne Frances Haugh <email@example.com>