User and Group Control Tools
User and Group Control Tools
Copyright(c) Management Analytics, 1995 - All Rights Reserved
Copyright(c), 1990, 1995 Dr. Frederick B. Cohen - All Rights Reserved
- The Login program allows users to specify a Uid and
password, and if they match, initializes the user by setting the Uid
and Gid, placing the user in a system specified directory, and
running a user specific program.
- The Su program allows users to change Uids by specifying a
new Uid and password. If they match, the system changes the effective
Uid, and creates a new process by running the same user specific
program that would be run at login for the same user.
- The Newgrp program allows users to change from their current
user group to other user groups that they are members of. If
the user is a member of the specified group, the call changes the
effective Gid, otherwise it fails.
- The Chown program changes the owner of a specified file.
This call only works if the effective Uid is that of the superuser.
- The Chgrp program changes the group of a specified file.
This call only works if the effective Uid is that of the superuser.
- The Who program lists the users currently logged into the
system.
- The Write program sends messages to another logged in user.
- The Wall program sends messages to all users logged into the
system.