(as root in X-terminal) Configuration tool for your printer(s). Settings go to the file /etc/printcap.
• setup
(as root) Configure mouse, soundcard, keyboard, X-windows,
system services. There are many distibution-specific configuration utilities,
setup is the default on RedHat. Mandrake 7.0 offers very nice DrakConf
.
• linuxconfig
(as root, either in text or graphical mode). You can
access and change hundreds of setting from it. Very powerful--don't change
too many things at the same time, and be careful with changing entries
you don't understand.
• xvidtune
(in X-terminal). Adjust the settings of the graphical
display for all resolutions so as to eliminate black bands, shift the display
right/left/up/down, etc. (First use the knobs on your monitor to fit your
text mode correctly on the screen.) To make the changes permanent, display
the frequencies on the screen and transfer them to the setup file /etc/X11/XF86Config.
• alias ls="ls --color=tty"
Create an alias for the command "ls" to enhance its format
with color. In this example, the alias is also called "ls" and the "color"
option is only envoke when the output is done to a terminal (not to files).
Put the alias into the file /etc/bashrc if you would like the alias to
be always accessible to all users on the system. Type "alias" alone to
see the list of aliases on your system.
• adduser user_name
Create a new account (you must be root). E.g.,
adduser barbara Don't forget to set up the password for the new user
in the next step. The user home directory is /home/user_name.
• useradd user_name
The same as the command " adduser user_name ".
• userdel user_name
Remove an account (you must be a root). The user's home
directory and the undelivered mail must be dealt with separately (manually
because you have to decide what to do with the files).
• groupadd group_name
Create a new group on your system. Non-essential but
can be handy even on a home machine with a small number of users.
• passwd
Change the password on your current account. If you are
root, you can change the password for any user using: passwd user_name
• chmod perm filename
(=change mode) Change the file access permission for
the files you own (unless you are root in which case you can change any
file). You can make a file accessible in three modes: read (r), write (w),
execute (x) to three classes of users: owner (u), members of the same group
as the owner (g), others on the system (o).
Check the current access permissions using:
ls -l filename
If the file is accessible to all users in all modes it
will show:
rwxrwxrwx
The first triplet shows the file permission for the owner
of the file, the second for his/her group, the third for others. A "no"
permission is shown as "-".
E.g., this command will add the permission to read the
file "junk" to all (=user+group+others):
chmod a+r junk
This command will remove the permission to execute the
file junk from others:
chmod o-x junk
You can set the default file permissions for the news
files that you create using the command umask (see man umask).
• chown new_ownername filename
chgrp new_groupname filename
Change the file owner and group. You should use these
two commands after you copy a file for use by somebody else.
• su
(=substitute user id) Assume the superuser (=root) identity
(you will be prompted for the password). Type "exit" to return you to your
previous login. Don't habitually work on your machine as root. The root
account is for administration and the su command is to ease your access
to the administration account when you require it. You can also use "su"
to assume any other user identity, e.g. su barbara will make me "barbara"
(password required unless I am a superuser).
