Red Hat NETSCAPE MANAGEMENT SYSTEM 6.0 - COMMAND-LINE Instrukcja Użytkownika Pobierz pdf (Strona 21)

• groupdel (8) - Delete a group

• groupmod (8) - Modify a group

• groups (1) - print the groups a user is in

• grpck (8) - verify integrity of group files

• pwconv (8) - convert to and from shadow passwords

• pwunconv (8) - convert to and from shadow passwords

• grpconv (8) - convert to and from shadow passwords

• grpunconv (8)- convert to and from shadow passwords

• vipw (8) - edit the password file

• vigr (8) - edit the group file

List user password settings

chage –l [account_name]

Change user password

settings

chage [account_name]

To set a non-expiring password, set the Maximum Password Age to 99999

Linux Security Admin

Guide

http://www.nic.com/~dave/SecurityAdminGuide/SecurityAdminGuide-

5.html

Permissions Discussion

UNIX/Linux has no per-user permissions/rights/policies. Everything is done on files, making sure who

can read/write/exectute the right files.

To check the current permissions of files, run "ls -l". If you run "ls -l /", to list all files in the root

directory, you will get output that looks something like this:

Code:

drwxr-xr-x 2 root root 4096 2003-07-15 22:41 bin

drwxr-xr-x 4 root root 1024 2003-07-16 03:26 boot

drwxr-xr-x 20 root root 118784 2003-07-16 03:32 dev

...

The first column (that looks like drwxr-xr-x) is the mode of the file. The first character indicates what

kind of file it is. d, as in this case, means directory. - means regular file, and then there are some other

file types of which you need not know more now, like named FIFOs, sockets, devices, etc.

The rwxr-xr-x is the permissions of file. The first rwx means that the owner of the file can read, write

and execute the file. For directories, the right to execute it means the right to use it. Just being able to

read a directory means that you can read what files are in the directory, but you won't be able to use

them without the execute permission on the directory. The first r-x means that those that are in the same

group as the file have read and execute permissions to the file. The second r-x means that all those that

are neither the owner of the file nor are in the same group as the file have read and execute permissions

on it. So r=read, w=write and x=execute, and the first group of three applies to the owner of the file, the

second group applies to those in the same group of the file, and the third group applies to all other users.

The second column (2, 4 and 20 in this case) is the number of links that the file has. Don't care about

that for now.

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 59 60

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Red Hat NETSCAPE MANAGEMENT SYSTEM 6.0 - COMMAND-LINE Instrukcja Użytkownika Strona 21