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Essential System Administration Pocket Reference by Æleen Frisch

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The root Account

su

su [-] [user] [-c "command"]Run a command as another user (defaults to root). If no command is specified, a new shell is started. If the initial hyphen is included, then the user’s login environment is duplicated.

 

Limiting access to su

 

AIX:

Limited to groups listed in the sugroups attribute for root in /etc/security/user.

 

FreeBSD:

Define the member list for group 0 as non-null.

 

Linux:

Use the pam_wheel module in the su file.

 

su log file

 

 

 

AIX:

/var/adm/sulog

FreeBSD:

/var/log/messages

 

HP-UX:

/var/adm/sulog

Linux:

/var/log/messages

 

Solaris:

Specified in the SULOG setting in /etc/default/ su.

Limiting direct root logins to the console

AIX:

chuser ttys="/dev/lft,/dev/tty0" rlogin=false root

FreeBSD:

Omit secure from all entries in /etc/ttys except console.

HP-UX:

/etc/securetty lists devices where root is allowed to log in (omit “/dev/” from the names).

Linux:

Use the pam_securetty module.

Solaris:

/etc/default/login: CONSOLE=/dev/console

Granting Limited root Powers

sudo

sudo [options] command

Run the specified command using the sudo facility. After successfully entering his password, a user can use the sudo command without having to re-enter it for a grace period (defaults to 5 minutes).

 

Options

 

-v

Reset the grace period to its full length.

 

-K

Terminate the grace period.

 

-u user

Run the command as the specified user (rather than root).

 

-l

List allowed commands for the current user ...

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