su - substitute user identity
su [-K | --no-kerberos] [-f] [-l | --full] [-m] [-i instance |
--instance=instance] [-c command | --command=command] [login [shell
su will use Kerberos authentication provided that an instance for the
user wanting to change effective UID is present in a file named .k5login
in the target user id’s home directory
A special case exists where ‘root’s’ ~/.k5login needs to contain an entry
for: ‘user/〈instance〉@REALM’ for su to succed (where 〈instance〉 is ‘root’
unless changed with -i).
In the absence of either an entry for current user in said file or other
problems like missing ‘host/hostname@REALM’ keys in the system’s keytab,
or user typing the wrong password, su will fall back to traditional
When using /etc/passwd authentication, su allows ‘root’ access only to
members of the group ‘wheel’, or to any user (with knowledge of the
‘root’ password) if that group does not exist, or has no members.
The options are as follows:
-K, --no-kerberos don’t use Kerberos.
-f don’t read .cshrc.
-l, --full simulate full login.
-m leave environment unmodified.
-i instance, --instance=instance root instance to use.
-c command, --command=command command to execute.