† Linux Befehle

Dies ist ein praktisches Auswahl der Befehle, die wir am häufigsten unter Linux verwenden. Die <Tab> Taste drückt man ums zu sehen welche Linux Kommandos verfügbar sind (im eigenen PATH). Auf meinem Linux System sagt mir die Ausgabe, dass mir 2595 Kommandos in meinem PATH verfügbar sind. Viele dieser “Befehle” können von Ihrem Lieblings Benutzeroberfläche (z.B. KDE oder Gnome) aus verwendet werden. Sie alle können von der Kommandozeile aus ausgeführt werden.

Erklärung:

<> = Sonder- oder Funktionstasten auf der Tastatur. Beispielsweise meint
<Ctrl> “control” Taste.

italic = Name einer Datei oder einer Variablen die durch Ihre eigene ersetzt wird.

fixed width = in-line Linux Kommandos & Filenamen.

Hinweise für die UNIX Bedienung:

  • Linux Groß- und Kleinschreibung. Als Beispiel: Netscape, NETSCAPE sind jeweils drei verschiedene Befehle. Auch meine_datei, meine_datei und meine_datei sind jeweils drei verschiedene Dateien. Ihren Benutzernamen und das Passwort sind auch Groß-und Kleinschreibungs abhängig.
    (Dies geht auf die Tradition von UNIX und der “c” Programmiersprache zurück welche ebenfalls case sensitive sind.)
  • Dateinamen können bis zu 256 Zeichen lang sein und Buchstaben als auch Nummern enthalten “.” (Punkt), “_” (Unterstrich), “-” (Bindestrich), plus sowie einige andere nicht erwähnte Zeichen.
  • Dateinamen die mit “.” beginnen sind werden normaln nicht mit dem ls (list) oder dir Kommando angezeigt. Diese Dateien sind “verseckt”. Benutze ls -a
    (list mit der option “all”) um auch diese Dateien zu sehen.
  • “/” is an equivalent to DOS “\” (root Verzeichnis, meaning the parent
    of all other directories).
  • Unter Linux werden alle Verzeichnisse in einem einzigen Verzeichnisbaum angezeigt (es gibt keine Laufwerksbuchstaben im DOS-Stil ).
  • In einer Konfigurationsdatei, eine Linie, beginnend mit # ist ein Kommentar.

Linux – wichtige Shortcuts & Kommandos

<Ctrl><Alt><F1>

Wechseln Sie in das erste Text-Terminal. Unter Linux können Sie zur gleichen Zeit mehrere (6 in der Standard Einstellung) Terminals eröffnet.

<Ctrl><Alt><Fn> (n=1..6)

Wechseln ins nächste Terminal

tty

Gibt den Namen des Terminals aus in dem sie sich gerade befinden.

<Ctrl><Alt><F7>

Wechselt ins GUI terminal (falls X-windows auf ihrem Linux Rechner läuft).

<Ctrl><Alt><Fn> (n=7..12)

Wechselt zum nächsten GUI terminal (falls ein GUI terminal auf screen
n-1 läuft). In der Standarteinstellung läuft aber normalerweise nichts in den Terminalfenstern

8 bis 12, aber das kann eingestellt werden.

<Tab>

(In einem Text Terminal) Vervollständigt automatisch das Kommando falls es einmalig ist, oder zeigt im anderen Fall eine Liste allr anderen Möglichkeiten.

<ArrowUp>

Scrollen und die Kommando History editieren. Drücken der <Enter> Taste um den Befehl auszuführen.

<Shift><PgUp>

Scrollen Terminal Ausgabe hoch. Funktioniert auch am login prompt, womit man sich die bootup messages ansehen kann.

<Shift><PgDown>

Scrollen Terminal Ausgabe runter.

<Ctrl><Alt><+>

(in X-windows) Ändern der X-server Auflösung (Wenn der X-server mit mehr als einer Auflösung konfiguriert ist). Für multible Auflösungen meiner SVGA Karte/Monitor, habe ich folgende Zeile in der Datei
/etc/X11/XF86Config (die erste Auflösung startet bei default, die größte bestimmt die Größe des “virtual screen”):

Modes "1024x768" "800x600" "640x480" "512x384" "480x300" "400x300"
"1152x864"

<Ctrl><Alt><->

(in X-windows) Ändern der X-server Auflösung in die Vorherige

<Ctrl><Alt><BkSpc>

(in X-windows) Beendet den momentanen X-windows server. Wird benutzt wenn der X-windows
server abstürzt und nicht normal beendet werden kann.

<Ctrl><Alt><Del>

Fährt das System herunter und rebootet. Dies ist der normale shutdown Befehl
für einen User auf der text-mode Console.

<Ctrl>c

Beendet den aktuellen Prozess (meist im text Modus bei kleinen Programmen).

<Ctrl>d

Logt aus dem aktuellen Terminal aus.

<Ctrl>d

Sendet [End-of-File] zum aktuellen Prozess. Nicht doppelt drücken den das bedeutet Logout

<Ctrl>s

Stopt den Transfare zum Terminal.

<Ctrl>q

Nimmt den Transfare zum Terminal wieder auf. Wird verwendet falls das Terminal mysteriöserweise
das responsing stoppt.

<Ctrl>z

Sendet den aktuellen Prozess in den Hintergrund

exit

Logout. Man kann auch logout verwenden, der das selbe bewirkt  (Falls eine zweite Shell gestartet wurde, e.g., verwende bash in der zweiten Shell
wird ausgelogt und man ist zurück in der ersten Shell)

reset

Restore a screwed-up terminal (a terminal showing funny characters)
to default setting. Use if you tried to “cat” a binary file. You may not
be able to see the Befehl as you type it.

<MiddleMouseButton>

Paste the text which is Aktuellely highlighted somewhere else. This
is the normal “copy-paste” operation in Linux.  (It doesn’t work with
Netscape and WordPerfect which use the MS Windows-style “copy-paste”. It
does work in the text terminal if you enabled “gpm” service using “setup”.)
Best used with a Linux-ready 3-button mouse (Logitech or similar) or else
set “3-mouse button emulation”).

~

(tilde) Das Home Verzeichnis (normally the Verzeichnis /home/my_login_name).
Beispielsweise, the Befehl cd ~/my_dir will Ändert my working
Verzeichnis to the subVerzeichnis “my_dir” under my home Verzeichnis.
Typing just “cd” alone is an equivalent of the Befehl “cd ~”.

.

(Punkt) Aktuelle Verzeichnis. Beispielsweise, ./my_program will attempt
to ausführen die Datei “my_program” located in your Aktuelles Arbeits Verzeichnis.

..

(Zwei Punkte) Verzeichnis parent to the Aktuelle one. Beispielsweise, the Befehl
cd
.. will Ändert my Aktuelle working Verzeichnis one one level up.

Common Linux Befehls–system info

pwd

Print working Direktory – Ausgabe des aktuellen Verzeichnisses, – zeigt den Namen meines aktuellen Verzeichnis
auf dem Bildschirm

hostname

Zeigt den Hostnamen (der Linux-Pc auf dem sie arbeiten).
Benutze netconf (Als root) um den Namen des Linux-PCs zu ändern

whoami

Ausgabe meines Login Namens.

id
username

Ausgabe der id (uid) und der Gruppen id (gid), der Effective id (falls anderst als die reale id) und die Supplementary Gruppen

date

Ausgabe oder Änderung des System Datums und der System Zeit. Beispielsweise kann man mit folgenem Befehl die Systemzeit auf 2010-12-31 23:57 ändern

date 123123572010

To set the hardware (BIOS) clock from the system (Linux) clock, use
the Befehl (Als root) setclock

time

Determine the amount of time that it takes for a process to complete
+ other info. Don’t confuse it with the date Befehl. E.g.

I can
find out how long it takes to display a Verzeichnis content using:

time ls

who

Determine the users logged on the machine.

rwho -a

(=remote who) Determine all users logged on your network. The rwho
service must be enabled for this Befehl to run. If it isn’t, run setup
Als root to enable “rwho”.

finger
user_name

System info about a user. Try: finger root

last

Zeigt eine Liste aller User die zu letzt in ihrem System eingeloggt waren.

history | more

Zeigt die letzten (100 oder so) Befehls ausführend from the Befehl line
on the Aktuelle account. The “| more” causes the display to stop after each
screenful.

uptime

Show the amount of time since the last reboot.

ps

(=print status) Listet alle Prozesse auf die aktuell unter dem aktuellen User laufen.

ps axu | more

List all the processes Aktuellely running, even those without the controlling
terminal, together with the name of the user that owns each process.

top

Keep listing the Aktuellely running processes, sorted by cpu usage (top
users first). In KDE, you can get GUI-based Ktop from “K”menu under “System”-”Task
Manager” (or by executing “ktop” in an X-terminal).

uname -a

(= Unix name with option “all”) Info on your (local) server. I can
also use guname (in X-window terminal) to display the info more
nicely.

free

Memory info (in kilobytes).

df -h

(=disk free) Print disk info about all the dateienystems (in human-readable
form)

du / -bh | more

(=disk usage) Print detailed disk usage for each subVerzeichnis starting
at the “/” (root) Verzeichnis (in human legible form).

cat /proc/cpuinfo

Cpu info–it show the content of the file cpuinfo. Note that
the dateien in the /proc Verzeichnis are not real dateien–they are
hooks to look at information available to the kernel.

cat /proc/interrupts

List the interrupts in use.

cat /proc/version

Linux Version und andere Informationen

cat /proc/dateienystems

Zeigt die Arten der Dateienysteme die momentan in Verwendung sind.

cat /etc/printcap

Zeigt die Eistellungen der Drucker.

lsmod

(Als root. Use /sbin/lsmod to ausführen this Befehl when you
are a non-root user.) Show the kernel modules Aktuellely loaded.


set|more

Show the Aktuelle user environment.

echo $PATH

Show the content of the environment variable “PATH”. This Befehl can
be used to show other environment variables as well. Use “set” to see the
full environment.

dmesg | less

Ausgabe der kernel messages (the content of the so-called kernel ring buffer).
Drücken “q” to quit “less”. Benutze less /var/log/dmesg to see
what “dmesg” dumped into this file right after the last system bootup.

Grundlegende Linux Operationen

any_Befehl
--help |more

Display a brief help on a Befehl (works with most Befehls). “–help”
works similar to DOS “/h” switch. The “more” pipe is needed if the output
is longer than one screen.

man
topic

Display the contents of the system manual pages (help) on the topic.
Try man man first. Drücken “q” to quit the viewer. The Befehl info
topic
works similar and may contain more up-to-date information. Manual pages
can be hard to read. Try any_Befehl --help for short,
easy to digest help on a Befehl. If more info needed, have a look to the
Verzeichnis /usr/doc. To display manual page from a specific section,
I may use something like in this example:  man 3 exit (this
displays an info on the Befehl exit from section 3 of the manual
pages).

apropos
topic

Give me the list of the Befehls that have something to to do with
my topic.

help Befehl

Display brief info on a bash (shell) build-in Befehl.

ls

List the content of the Aktuelle Verzeichnis. Under Linux, the Befehl
“dir” is an alias to ls. Many users have “ls” to be an alias to “ls –color”.

ls -al |more

List the content of the Aktuelle Verzeichnis, all dateien (also those starting
with a dot), and in a long form. Pipe the output through the “more” Befehl,
so that the display pauses after each screenful.

cd
Verzeichnis

Ändert Verzeichnis. Using “cd” without the Verzeichnis name will take you
to your home Verzeichnis. “cd -” will take you to your previous Verzeichnis
and is a convenient way to toggle between two directories. “cd ..” will
take you one Verzeichnis up.

cp
source destination

Dateien kopieren. E.g., cp /home/stan/existing_file_name .
will copy a file to my Aktuelle working Verzeichnis. Use the “-r” option (for
recursive) to copy the contents of whole directories, e.g. , cp -r
my_existing/dir/ ~ will copy a subVerzeichnis under my Aktuelle
working Verzeichnis to my home Verzeichnis.

mcopy
source destination

Kopiert eine Datei from/to a DOS dateienystem (no mounting necessary). E.g.,
mcopy
a:\autoexec.bat ~/junk . See man mtools for related Befehls:
mdir, mcd, mren, mmove, mdel, mmd, mrd, mformat ….

mv source destination

Move or rename dateien. The same Befehl is used for moving and renaming
dateien and directories.

ln
source destination

Erstellt a hard link called destination to the file called source.
The link appears as a copy of the original dateien, but in reality only one
copy of the file is kept, just two (or more) Verzeichnis entries point to
it. Any Änderts the file are automatically visible throughout. When one
Verzeichnis entry is Entferntd, the other(s) stay(s) intact. The limitation
of the hard links are: the dateien have to be on the same dateienystem, hard
links to directories or special dateien are impossible.

ln -s source destination

Erstellt einen Symbolic (soft) Link called “destination” to the file called
“source”. The symbolic link just specifies a path where to look for the
file. In contradistinction to hard links, the source and destination don’t
not have to tbe on the same dateienystem. In comparison to hard links, the
drawback of symbolic links are: if the original file is Entferntd, the link
is “broken”, symbolic links can also Erstellt circular references (like circular
references in spreadsheets or databases, e.g., “a” points to “b” and “b”
points back to “a”).

rm dateien

Entfernt (delete) dateien. You must own the file in order to be able to
Entfernt it. On many systems, you will be asked or confirmation of deleation,
if you don’t want this, use the “-f” (=force) option, e.g., rm -f *
will Entfernt all dateien in my Aktuelle working Verzeichnis, no questions asked.

mkdir
Verzeichnis

Make a new Verzeichnis.

rmdir
Verzeichnis

Entfernt an empty Verzeichnis.

rm -r dateien

(recursive Entfernt) Entfernt dateien, directories, and their subdirectories.
Careful with this Befehl Als root–you can easily Entfernt all dateien on the
system with such a Befehl ausführend on the top of your Verzeichnis tree,
and there is no undelete in Linux (yet). But if you really wanted to do
it (reconsider), here is how (Als root):
rm -rf /*

cat filename | more

View the content of a text file called “filename”, one page a time.
The “|” is the “pipe” symbol (on many American keyboards it shares the
key with “\”) The pipe makes the output stop after each screenful. For
long dateien, it is sometimes convenient to use the Befehls head and tail
that display just the beginning and the end of the file. If you happened
to use “cat” a binary file and your terminal displays funny characters
afterwards, you can restore it with the Befehl “reset”.

less
filename

Scroll through a content of a text file. Drücken q when done. “Less”
is roughly equivalent to “more” , the Befehl you know from DOS, although
very often “less” is more convenient than “more”.

pico
filename

Edit a text file using the simple and standard text editor called pico.

pico -w filename

Edit a text file, while disabling the long line wrap. Handy for editing
configuration dateien, e.g. /etc/fstab.

find / -name “filename“

Find the file called “filename” on your dateienystem starting the search
from the root Verzeichnis “/”. The “filename” may contain wildcards (*,?).

locate
filename

Find the file name of which contains the string “filename”. Easier
and faster than the previous Befehl but depends on a database that normally
rebuilds at night.

./program_name

Run an executable in the Aktuelle Verzeichnis, which is not on your PATH.

touch
filename

Ändert the date/time stamp of the file filename to
the Aktuelle time. Erstellt an empty file if the file does not exist.

xinit

Start a barebone X-windows server (without a windows manager).

startx

Start an X-windows server and the default windows manager. Works like
typing “win” under DOS with Win3.1

startx — :1

Start another X-windows session on the display 1 (the default is opened
on display 0). You can have several GUI terminals running conAktuellely.
Switch between them using <Ctrl><Alt><F7>, <Ctrl><Alt><F8>,
etc.

xterm

(in X terminal) Run a simple X-windows terminal.  Typing exit will close it.  There are other, more advanced “virtual” terminals
for X-windows. I like the popular ones: konsole and kvt
(both come with kde) and gnome-terminal (comes with gnome).
If you need something really fancy-looking, try Eterm.

xboing

(Im X terminal). Very nice, old-fashioned game. Many small games/programs
are probably installed on your system. I also like xboard (chess).

shutdown -h now

(Als root) Shut down the system to a halt. Mostly used for a remote
shutdown. Use <Ctrl><Alt><Del> for a shutdown at the console (which
can be done by any user).

halt

reboot

(Als root, zwei Befehle) Halt or reboot the machine. Used for remote
shutdown, simpler to type than the previous Befehl.

Network apps

netscape

(Im X terminal) Run netscape (requires a separate Netscape installation).
The Aktuelle versions of Netscape (4.x) are known to be big and buggy. They
occasionally crash by vanishing (no other harm done). Also, when not connected
to the network , Netscape likes to refuse to do anything (looks like it
hanged)-it revives when you connect.

netscape -display host:0.0

(in X terminal) Run netscape on the Aktuelle machine and direct the
output to machine named “host” display 0 screen 0. Your Aktuelle machine
must have a Dateirechte to display on the machine “host” (typically given
by executing the Befehl xhost
Aktuelle_machine_name in
the xterminal of the machine host. Other X-windows program can be run remotely
the same way.

lynx
file.html

Zeigt eine html Datei oder surft zur nexten webseite im Text mode.

pine

Ein gutes text-mode E-Mail Programm. Another good and standard one is elm.
Your Netscape mail will read the mail from your Internet account. pine will let you read the “local” mail, e.g. the mail your son or a cron process
sends to you from a computer on your home network. The Befehl mail
could also be used for reading/composing mail, but it would be inconvenient–it
is meant to be used in scripts for automation.

elm

Ein gutes tex-mode Email Programm. In etwa wie das vorherige Programm.

mutt

A really basic but extremally useful and fast mail reader.

mail

A basic operating system tool for e-mail. Look at the previous Befehls
for a better e-mail reader. mail is good if you wanted to send
an e-mail from a shell script.

licq

(in X term) An icq “instant messaging” client. Another good one is kxicq.
Older distributions don’t have an icq client installed, you have to do
download one and install it.

talk
username1

Talk to another user Aktuellely logged on your machine (or use “talk
username1@machinename”
to talk to a user on a different computer) . To accept the invitation to
the conversation, type the Befehl “talk
username2“. If
somebody is trying to talk to you and it disrupts your work, your may use
the Befehl “mesg n” to refuse accepting messages. You may want
to use “who” or “rwho” to determine the users who are
Aktuellely logged-in.

mc

Startet den “Midnight Commander” Datei Manager (ist in etwa wie der bekannte “Norton commander”
für Windows).

telnet
server

Connect to another machine using the TELNET protocol. Use a remote
machine name or IP address. You will be prompted for your login name and
password–you must have an account on the remote machine to login. Telnet
will connect you to another machine and let you operate on it as if you
were sitting at its keyboard (almost). Telnet is not very secure–everything
you type goes in open text, even your password!

rlogin
server

(=remote login) Connect to another machine. The login name/password
from your Aktuelle session is used; if it fails you are prompted for a password.

rsh
server

(=remote shell) Yet another way to connect to a remote machine. The
login name/password from your Aktuelle session is used; if it fails you
are prompted for a password.

ftp
server

Ftp another machine. (There is also ncftp which adds extra
features and gftp for GUI .) Ftp is good for copying dateien to/from
a remote machine. Try user “anonymous” if you don’t have an account on
the remote server. After connection, use “?” to see the list of available
ftp Befehls.  The essential ftp Befehl are: ls (see the
dateien on the remote system), ASCII,
binary (set the file
transfer mode to either text or binary, important that you select the proper
one ), get (copy a file from the remote system to the local system),
mget
(get many dateien at once), put (copy a file from the local system
to the remote system), mput (put many dateien at once), bye
(disconnect). For automation in a script, you may want to use
ncftpput
and ncftpget, Beispielsweise:

ncftpput -u my_user_name -p my_password -a remote.host.domain remote_dir
*local.html

minicom

Minicom Programm (sieht in etwa aus wie “Procomm for Linux”).

Dateien Packen und Entpacken

tar -zxvf filename.tar.gz

(=tape archiver) Untar a tarred packt einen tarball (*.tar.gz or
*.tgz) that you downloaded from the Internet.

tar -xvf filename.tar

Untar a tarred aber nicht gepackten tarball (*.tar).

gunzip
filename.gz

Entpackt eine gezippte Datei (*.gz” or *.z). Use gzip (also zip
or comDrücken) if you wanted to comDrücken dateien to this file format.

bunzip2
filename.bz2

(=big unzip) Entpackt a file (*.bz2) zipped mit dem bzip2 Packprogramm
utility. Wird für größere Dateien verwendet

unzip
filename.zip

Entpackt eine Datei (*.zip) das gepackt ist mit einem Packprogramm das kompatibel ist
zu WINZIP für Windows.

unarj e filename.arj

Extract the content of an *.arj archive.

uudecode -o outputfile filename

Decode a file encoded with uuencode.  uu-encoded dateien
are typically used for transfer of non-text dateien in e-mail (uuencode transforms
any file into an ASCII file).

Prozesse in Linux

ps

(=print status) Display the list of Aktuellely running
processes with their process IDs (PID) numbers. Use ps axu to
see all processes Aktuellely running on your system (also those of other
users or without a controlling terminal), each with the name of the owner.
Use “top” to keep listing the processes Aktuellely running.

fg
PID

Bring a background or stopped process to the foreground.

bg
PID

Send the process to the background. Opposite to fg. The same can be
accomplished with <Ctrl>z.  If you have stopped jobs, you have
to type exit twice in row to log out.

any_Befehl&

Run any Befehl in the background (the symbol “&” means “run the
proceeding Befehl in the background”).

batch any_Befehl

Run any Befehl (usually one that is going to take more time) when
the system load is low. I can logout, and the process will keep running.

at 17:00

ausführen a Befehl at a specified time.  You will be prompted for
the Befehl(s) to run, until you Drücken <Ctrl>d.

kill
PID

Force a process shutdown. First determine the PID of the process to
kill using ps.

killall
program_name

Kill program(s) by name.

xkill

(in an xwindow terminal) Kill a GUI-based program with mouse. (Point
with your mouse cursor at the window of the process you want to kill and
click.)

lpc

(Als root) Check and control the printer(s). Type “?” to see the list
of available Befehls.

lpq

Show the content of the printer queue. Under KDE (X-Windows), you may
use GUI-based “Printer Queue” available from “K”menu-Utilities.

lprm
job_number

Entfernt a printing job “job_number” from the queue.

nice
program_name

Run
program_name adjusting its priority. Since the priority
is not specified in this example, it will be adjusted by 10 (the process
will run slower), from the default value (usually 0). The lower the number
(of “niceness” to other users on the system), the higher the priority.
The priority value may be in the range -20 to 19. Only root may specify
negative values. Use “top” to display the priorities of the running processes.

renice -1 PID

(Als root) Ändert the priority of a running process to -1. Normal users
can only adjust processes they own, and only up from the Aktuelle value
(make them run slower).

<Ctrl>c, <Ctrl>z, <Ctrl>s, and <Ctrl>q
also belong to this chapter but they were described previously.
In short they mean: stop the Aktuelle Befehl, send the Aktuelle Befehl
to the background, stop the data transfer, resume the data transfer.

Grundlegende Linux Administrations Befehle

printtool

(Als root Im X-Terminal) Configuration tool for your printer(s). Settings
go to the file /etc/printcap.

setup

(Als 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

(Als root, either in text or graphical mode). You can access and Ändert
hundreds of setting from it. Very powerful–don’t Ändert too many things
at the same time, and be careful with changing entries you don’t understand.

xvidtune

(Im 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 Änderts permanent, display the frequencies
on the screen and transfer them to the setup file /etc/X11/XF86Config.

alias ls=”ls –color=tty”

Erstellt an alias for the Befehl “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 dateien). 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

Erstellt 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 Verzeichnis is
/home/user_name.

useradd
user_name

Das selbe wie der Befehl ” adduser
user_name ".

userdel
user_name

Löscht einen Account (funktioniert nur als root). The user’s home Verzeichnis and
the undelivered mail must be dealt with separately (manually because you
have to decide what to do with the dateien).

groupadd
group_name

Erstellt a new group on your system. Non-essential but can be handy even
on a home machine with a small number of users.

passwd

Ändert the password on your Aktuelle account. If you are root, you can
Ändert the password for any user using:  passwd
user_name

chmod perm filename

(=Dateirechte ändern) Ändert the file access Dateirechte for the dateien you
own (unless you are root in which case you can Ändert any file). You can
make a file accessible in three modes: read (r), write (w), ausführen (x)
to three classes of users: owner (u), members of the same group as the
owner (g), others on the system (o). Check the Aktuelle access Dateirechtes
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 Dateirechte for the owner of the file,
the second for his/her group, the third for others. A “no” Dateirechte is
shown as “-”.

E.g., this Befehl will add
the Dateirechte to read the file
“junk” to all (=user+group+others):

chmod a+r junk

Dieser Befehl will Entfernt the Dateirechte to ausführen the file junk from
others:

chmod o-x junk

You can set the default file Dateirechtes for the news dateien that you
Erstellt using the Befehl umask (see man umask).

chown
new_ownername filename

chgrp new_groupname filename

Ändert Dateibesitzer und die Gruppe. You should use these two Befehls
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 Als root. The root account
is for administration and the su Befehl 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).

kernelcfg

(Als root in X terminal). GUI to to add/Entfernt kernel modules. You can
do the same from the Befehl line using the Befehl “insmod“,
but “insmode” is less “newbie-friendly”.

lsmod

Listet die aktuellen geladenen Kernel Module auf. A module is like a device driver–it
provides operating system kernel support for a particular piece of hardware
or feature.

modprobe -l |more

List all the modules available for your kernel. The available modules
are determined by how your Linux kernel was compliled. Every possible module/feature
can be compiled on linux as either “hard wired” (fast, non-removable),
“module” (maybe slower, but loaded/removable on demand), or “no” (no support
for this feature at all).

insmod parport

insmod ppa

(Als root) Insert modules into the kernel (a module is roughly an equivalent
of a DOS device driver). This example shows how to insert the modules for
support of the external parallel port zip drive (it appears to be a problem
to get the external zip drive to work  in any other way under RH6.0
).

rmmod
module_name

(Als root). Entfernt the module module_name from
the kernel.

setserial /dev/cua0 port 0×03f8 irq 4

(Als root) Set a serial port to a non-standard setting. The example
here shows the standard setting for the first serial port (cua0 or ttyS0).
The standard PC settings for the second serial port (cua1or ttyS1) are:
address of i/o port 0×02f8, irq 3. The third serial port (cua2 or ttyS2):
0×03e8, irq 4. The forth serial port (cua3 or ttyS3): 0×02e8, irq 3. Add
your setting to /etc/rc.d/rc.local if you want it to be set at
the boot time. See man setserial for good a overview.

fdisk

(Als root) Linux hard drive partitioning utility (DOS has a utility
with the same name).

cd /usr/src/linux-2.0.36

make xconfig

(Als root in X terminal). Nice GUI front-end for configuration of the
kernel options in preparation for compilation of your customized kernel.
(The Verzeichnis name contains the version of your Linux kernel so you may
need to modify the Verzeichnis name if your Linux kernel version is different
than 2.0.36 used in this example. You also need the “Tk” interpreter and
the kernel source code installed. ) The alternatives to “make xconfig”
are: “make config”  (runs a scripts that asks you questions in the
text mode) and “make menuconfig” (runs a text-based menu-driven configuration
utility).

Try:

less /usr/doc/HOWTO/Kernel-HOWTO for more information.

After the configuration,  you may choose to proceed with kernel
compilation of the new kernel by issuing the following Befehls:

make dep

make zImage

The last Befehl will take some time to complete (maybe 0.5 h, depending
on your hardware). It produces the file “zImage”, which is your new Linux
kernel. Next:

make modules

make modules_install

Read: /usr/doc/HOWTO/Kernel-HOWTO for information on how to install
the new kernel. You will probably also find it useful to read “man depmode”.
Configuration, compilation and installation of a new kernel is not difficult
but it CAN lead to problems if you don’t know what you are doing.

Compilation of a kernel is a good way to test your hardware, because
it involves a massive amount of computing. If your hardware is “flaky”,
you will most likely receive the “signal 11″ error.

depmod -a

(Als root) Build the module dependency table for the kernel. This can,
Beispielsweise, be useful after installing and booting a new kernel. Use “modprobe
-a” to load the modules.

ldconfig

(Als root) Re-Erstellt the bindings and the cache for the loader of dynamic
libraries (“ld”). You may want to run ldconfig after an installation of
new dynamically linked libraries on your system. (It is also re-run every
time you boot the computer, so if you reboot you don’t have to run it manually.)

mknod /dev/fd0 b 2 0

(=make node, Als root) Erstellt a device file. This example shows how
to Erstellt a device file associated with your first floppy drive and could
be useful if you happened to accidentally erase it. The options are: b=block
mode device (c=character mode device, p=FIFO device, u=unbuffered character
mode device). The two integers specify the major and the minor device number.

fdformat /dev/fd0H1440

mkfs -c -t ext2

(=floppy disk format, two Befehls, Als root) Perform a low-level formatting
of a floppy in the first floppy drive (/dev/fd0), high density (1440 kB).
Then make a Linux dateienystem (-t ext2), checking/marking bad blocks (-c
). Making the dateien system is an equivalent to the high-level format.

badblocks /dev/fd01440 1440

(Als root) Check a high-density floppy for bad blocks and display the
results on the screen. The parameter “1440″ specifies that 1440 blocks
are to be checked. This Befehl does not modify the floppy.

fsck -t ext2 /dev/hda2

(=file system check, als root) Check and repair a dateienystem. The example
uses the partition hda2, dateienystem type ext2.

dd if=/dev/fd0H1440 of=floppy_image

dd if=floppy_image of=/dev/fd0H1440

(Zwei Befehls, dd=”data duplicator”) Erstellt ein Image einer Diskette to
the file called “floppy_image” in the Aktuelle Verzeichnis. Then copy floppy_image (file) to another floppy disk. Works like DOS “DISKCOPY”.

Programme unter Linux Installieren

rpm -ivh filename.rpm

(=RedhatPackageManager, install, verbose, hashes displayed to show
progress, Als root.) Install a content of RedHat rpm package(s) and print
info on what happened. Keep reading if you prefer a GUI installation.

rpm -qpi filename.rpm

(=RedhatPackageManager, query, package, list.) Read the info on the
content of a yet uninstalled package
filename.rpm.

rpm -qpl filename.rpm

(=RedhatPackageManager, query, package, information.) List the dateien
contained in a yet uninstalled package
filename.rpm.

rpm -qf filename

(=RedhatPackageManager, query, file.) Find out the name of the *.rpm
package to which the file
filename (on your hardrive) belongs.

rpm -e packagename

(=RedhatPackageManager, erase=uninstall.) Uninstall a package pagckagename.
Packagname
is the same as the beginning of the *.rpm package file but without the
dash and version number.

kpackage

gnorpm

glint

(Im X terminal, Als root if you want to be able to install packages)
GUI fronts to the Red Hat Package Manager (rpm). “glint” comes with RH5.2,
“gnorpm” with RH6.0, “kpackage” comes with RH6.1 or must be installed separately
but is the best of the three. Use any of them to view which software packages
are installed on your system and the what not-yet-installed packages are
available on your RedHat CD, display the info about the packages, and install
them if you want (installation must be done Als root).

Zugriff auf Festplatten und Partitionen unter Linux

mount

Mounting drives.  Examples are shown in the next Befehls.

mount -t auto /dev/fd0 /mnt/floppy

(Als root) Mount the floppy. The Verzeichnis /mnt/floppy must
exist, be empty and NOT be your Aktuelle Verzeichnis.

mount -t auto /dev/cdrom /mnt/cdrom

(Als root) Mount the CD. You may need to Erstellt/modify the /dev/cdrom
file depending where your CDROM is. The Verzeichnis /mnt/cdrom must
exist, be empty and NOT be your Aktuelle Verzeichnis.

mount /mnt/floppy

(as user or root) Mount a floppy as user. The file /etc/fstab
must be set up to do this. The Verzeichnis
/mnt/floppy must not
be your Aktuelle Verzeichnis.

mount /mnt/cdrom

(as user or root) Mount a CD as user. The file /etc/fstab
must be set up to do this. The Verzeichnis
/mnt/cdrom must not be
your Aktuelle Verzeichnis.

umount /mnt/floppy

Unmount the floppy. The Verzeichnis
/mnt/floppy must not be
your (or anybody else’s) Aktuelle working Verzeichnis. Depending on your setup,
you might not be able to unmount a drive that you didn’t mount.

Network administration Tools

netconf

(Als root) A very good menu-driven setup of your network.

pingmachine_name

Check if you can contact another machine (give the machine’s name or
IP), Drücken <Ctrl>C when done (it keeps going).

route -n

Show the kernel routing table.

nslookup
host_to_find

Query your default domain name server (DNS) for an Internet name (or
IP number) host_to_find. This way you can check if your DNS works.
You can also find out the name of the host of which you only know the IP
number.

traceroute host_to_trace

Have a look how you messages trave to host_to_trace
(which is either a host name or IP number).

ipfwadm -F -p m

(for RH5.2, seen next Befehl for RH6.0) Set up the firewall IP forwarding
policy to masquerading. (Not very secure but simple.) Purpose: all computers
from your home network will appear to the outside world as one very busy
machine and, Beispielsweise, you will be allowed to browse the Internet from
all computers at once.

echo 1 > /proc/sys/net/ipv4/ip_forward

ipfwadm-wrapper -F -p deny

ipfwadm-wrapper -F -a m -S xxx.xxx.xxx.0/24 -D 0.0.0.0/0

(Drei Befehls, RH6.0). Does the same as the previous Befehl. Substitute
the “x”s  with digits of your class “C” IP address that you assigned
to your home network. See here
for more details. In RH6.1, masquarading seems broken to me–I think I
will install Mandrake Linux:).

ifconfig

(Als root) Display info on the network interfaces Aktuellely active (ethernet, ppp, etc). Your first ethernet should show up as eth0, second
as eth1, etc, first ppp over modem as ppp0, second as ppp1, etc. The “lo”
is the “loopback only” interface which should be always active. Use the
options (see ifconfig --help) to configure the interfaces.

ifup interface_name

(/sbin/ifup to it run as a user) Startup a network interface.
E.g.:

ifup eth0

ifup ppp0

Users can start up or shutdown the ppp interface only when the right
Dateirechte was checked during the ppp setup (using netconf ).
To start a ppp interface (dial-up connection), I normally use kppp available
under kde menu “internet”.

ifdown
interface_name

(/sbin/ifdown to run it as a user). Shut down the network
interface. E.g.: ifdown ppp0 Also, see the previous Befehl.

netstat | more

Displays a lot (too much?) information on the status of your network.

Musik bezogene Linux Befehle

cdplay play 1

Play the first track from a audio CD.

eject

Eject the CD
ROM tray

play my_file.wav

Spielt eine wave Datei ab.

mpg123 my_file.mp3

Spielt eine mp3 Datei ab.

mpg123 -w my_file.wav my_file.mp3

Erstellt a wave audio file from an mp3 audio file.

knapster

(in X Terminal) Start the program to downolad mp3 dateien that other
users of napster have displayed for downloading. Really cool!

cdparanoia -B  “1-”

(CD ripper)  Read the contents of an audio CD and save it into
wavedateien in the Aktuelle directories, one track per wavefile.  The
“1-”

means “from track 1 to the last”. -B forces putting each track into
a separate file.

playmidi my_file.mid

Spielt eine midi Datei ab.  playmidi -r my_file.mid
will display text mode effects on the screen.

sox

(argument not given here) Convert from almost any audio file format
to another (but not mp3s).  See man sox.

Graphik bezogene Linux Befehle

kghostview my_file.ps

Zeigt eine postscript file auf dem Bildschirm.  I can also use the older-looking ghostview
or gv for the same end effect.

ps2pdf my_file.ps my_file.pdf

Erstellt eine pdf (Adobe portable document format) Datei aus einer postscript
Datei.

gimp

(in X terminal) A humble looking but very powerful image processor.
Takes some learning to use, but it is great for artists, there is almost
nothing you can’t do with gimp. Use your mouse right button to get local
menus, and learn how to use layers. Save your file in the native gimp file
format *.xcf (to preserve layers) and only then flatten it and save as
png (or whatever).  There is a large user manual /usr/

gphoto

(in X terminal) Mächtiger Foto Editor.

giftopnm my_file.giff > my_file.pnm

pnmtopng my_file.pnm > my_file.png

Convert the propriatory giff graphics into a raw, portable pnm file.
Then convert the pnm into a png file, which is a newer and better standard
for Internet pictures  (better technically plus there is no danger
of being sued by the owner of giff patents).