Linux Command Reference

 

CREATED: November 2000 

Updated: 12-2001,12-2005, 07-2008, 09-27-2009

 

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Pros and Cons of Linux

 

PROS: Free alternative to Microsoft Windows.  Designed and supported for the benefit of the human race.  Very solid core operating system.

 

CONS:  Weak x-window shell (the point and click desktop interface); Gnome and KDE are easily broken and it can be difficult to fix.  Installing and uninstalling software is overly complex. 

 

TIP: Install Fedora by creating a virtual machine with Virtual Box by Sun.  This helps keep a clear separation between windows and linux on your PC. ==================================================================================================

Case: Linux is usually case sensitive: Type “clear” not “Clear” or “CLEAR”.

 

COMMAND

DESCRIPTION

ARGUMENTS

EXAMPLE

 

 

 

 

 

 

 

 

 

Terminal

MacOS X (Unix) search for this using spotlight so you can open a command shell where many of the commands here will help you.

Command key + space bar, type terminal.  A shortcut can be added to the desktop or the dock.

 

updatedb (creates and then updates the quick search file database(file index) that the locate command uses.)

Updates the rapid search data base.  If it has never run it must be run manually first.  Don’t forget to login as root.

 

Open a terminal window, type su root <Enter> then the root password then…

updatedb <Enter>

 

 

 

 

alias

(not to be confused with a Symbolic Link – which is what a shortcut is in Microsoft Windows)

 

These command-line shortcuts save a lot of typing. 

 

TIP: You can recreate the same dos shortcuts you may be used to ex

dos cls or clear screen is done with “clear” in Unix you could type alias ‘cls=clear’

alias <Enter> will show what alias’s are currently setup – note do to a bug some may appear messed up or different than you typed.

 

 

EXAMPLES IN /etc/bashrc.bash

 

# Do not leave any space see example

# correct: del='rm -rf' wrong: del = 'rm -rf'

#

alias  d='clear ; ls -all -h ; pwd'

alias  del='rm -rf'

alias  cls='clear'

alias  vismb='vi /etc/samba/smb.conf'

alias  restartsmb='/etc/rc.d/init.d/smb restart; sleep 2; smbclient -NL fedora'

alias  vibash='vi /etc/bashrc'

alias  vimsg='vi /var/log/messages'

alias  cpsys='cp /etc/samba/smb.conf /windows/sysinfo/ cp /etc/bashrc /windows/sysinfo/'

alias shut='shutdown -h now'

alias x='startx'

alias www='cd /var/www/cgi-bin/;chmod +755 *; clear; ls -all -h; pwd'

alias viipaddr='cd /etc/sysconfig/network-scripts/; ls -all ifcfg-eth*'

 

alias kde='switchdesk kde | startx'

 

alias locateupdate='/etc/cron.daily/slocate.cron'

#the above localupdate will force locate database of all files on

# the hard drive to be updated.

 

each time you logout or restart the Unix box the alias will be forgotten.  To make the system remember and load it each time go to this file but be careful because it is critical.

 

TIP Get familiar with the vi dos shell text editor first the basics of vi aren’t hard but vi will frustrate the hell out of you until you learn its basics commands!!!!!!!!

 

cd /etc

 

vi bashrc <Enter>

 

inside the vi editor DON’T JUST START PRESSING KEYS UNLESS YOU KNOW HOW TO DO THINS IN VI!!!!!

press the insert key on your keyboard use down arrow to go to last empty line press <Enter> key several times.

 

now type

alias ‘cls=clear’

now press the esc or escape key to exit insert or typing mode press  the shift key and hold it down now press the letter Z twice this will save and exit.  IF YOU MADE ANY MISTAKES PRES ESC KEY THEN SHIFT AND THE : COLON KEY NOW TYPE  q! <Enter> this will exit  you without saving and you can try again.

 

 

Apache (httpd)

This is the default Linux Web server that dominates the internet (~ 65%).

 

httpd is http protocol d stands for daemon which just means a service that your computer is providing.

Where is my home page?

 

/var/www/html/ directory the file name is index.htm.  To edit it from the DOS Window/shell prompt type:

 

vi /var/www/html/index.htm <Enter>

 

Tip: make a backup copy of files before editing them.  Ex. type

cp index.htm index_bk.htm <Enter>

service xinetd restart

service httpd restart <Enter>

Bash (see shell in this chart)

 

How do I know what shell I’m in?  From any shell type echo $0<Enter> (zero not “Oh”)

This is one of the “dos” shells or really shell prompt environments you can work in.  It is my favorite and I highly recommend it for beginners + advanced users too.  It has cool stuff like the up and down arrow keys will scroll through commands you type – not all shells do this.

A number of commands or features are available in this shell that the ‘c’ shell or korn or borne shell don’t support.

There is a version written for Sun Solaris Unix that can be install on Sun.

 

 

calculator

type bc

Simple system calculator

NONE

 

 

bc <Enter>

now type a calculation ex 5*50 <Enter>

 

TO EXIT: type quit <Enter>

cd (see pwd)

Change directory.  Careful most common mistakes is not leaving a space between cd and .. or / in ms dos you can type it either way.

..   backs up one dir or folder level at a time

/  go to the highest level of the hard drive useful if you then want to search for a file through entire HD.

 

cd <Enter> will take you to the “home” directory of the user you are currently logged in under.

 

cd – go to last dir you were in

 

 

 

 

cd [space] ..     wrong “cd..”     right “cd ..”

wrong dos way cd\   wrong Unix way   cd/  correct Unix way cd [space] /   or  cd /

 

this example works from any dir you’re in because is spells out the full or “absolute” path  go to a folder called  /dir1/dir2/dir3

 

cd /dir1/dir2/dir3/  notice the slash on the end it clearly tells the system dir3 is a directory NOT A FILE CALLED dir3.

 

 

CDROM Access

To do a manual mount at the shell prompt type:

 

mount –t iso9660  /dev/cdrom  /mnt/cdrom <Enter>

 

type cd  /mnt/cdrom <Enter>

 

now type ls –1  or dir –1 to see a directory of the CD  contents. (remember a CDROM disc must be present in the drive)

cfdisk (also see fdisk)

Great Non-Windows MENU - driven utility that shows you all your hard disk partitions and hard drives at a glance. 

Use the tab key to navigate menu choices and arrows to select drive  or partition - Warning be careful this util can delete partitions and chg the bootable status etc.

cfdisk <Enter>

chmod (also see chown)

Modify the permission “Mode” this is basically a built-in set of file or

 access permissions expressed in hexadecimal #’s.

755 (rwxr-r-) read write eXexute read

typically used for web pages.

 

-R recursively chg permissions

chmod 755 mydocument.txt

 

“no such file or directory” err msg when trying to execute a perl script.

chown

Change Owner

also see chmod

change owner

-h changes the ownership of a symbolic link (shortcut) but not the file that it points to.

 

-f suppress error messages.

 

-R Descends directories Recursively (allows you to make the change effective in all subdirectories

 

EXAMPLE:

chown mrbios:mrbios  filename

this says change the ownership to the user mrbios and the group mrbios with a colon in-between then the filename you wish to do this to.

 

Chown userID:GroupID  filename  if you don’t specify a group then just the owner will change and the group will not.

 

WARNING: this can create havoc esp. if different sub directories grant access that is not granted in the upper level directory this will strip those owners.  (continued…  -> )

(continued…)

Ex Top level dir folder called  Data contains Admin and Root.  but below are all the end user’s sub directories each end user has ownership or access to their folder if you are working in DATA and do a chown –R and make the owner root this will strip any other owners out of the individual end users folders and all end users will now not be able to access their folders (home directories).  You will then need to re add them one at a time on a folder by folder basis. Or restore from tape backup.

 

chown –R root:apache  *

 

meaning ch all subfolders and files  to userID of root and a GroupID of apache

 

 

clear

clears the screen same as dos cls command.

 

clear  <Enter>

copy file

see cp

 

 

cp

copies a file

-R copy and creates sub dir's as needed.

 

src: . or *.*

cp -R /Source_dir   /Destination_dir

ex:

cp -R . /Destination_dir <TIP> Destination dir must exist or will not copy.

 

-R Recursive copy and all cmd line arguments must come first before src and dst dir’s.

 

cp = copy file

Copy file

 

cp file1.txt file1_bkup.txt <Enter>

ctrl+alt F1

Break out of an Xwindows hang

 

follow up with ctrl+c a few times to break out once you are back at the shell prompt.

Customize Default

Windows shell prompt

Customize Default Appearance of shell prompt windows under KDE environment

 

Get a nice EZ on the eyes shell prompt under KDE x-windows shell.

N/A

Click on “Terminal Emulation” Icon usually at bottom of screen.  Now a dos shell should be open click on Options, Schema, chk “White on Black”, then click on Options, Font, chk Huge – if using large monitor.

 

Finally, to save changes: click Options, Save Options. If you don’t the preference setting will get forgotten.

daemon

pronounced demon.

 

Very important item / concept in Linux and windows 2000/NT and even windows 9x/ME.

 

Remember it’s this simple:

 

daemon = service and service = daemon.

 

this explains the magic letter ‘d’ that so often follows name that would make sense then get a ‘d’ slapped on the end.

 

Ex: http heard of  it?  how about httpd now it seems mysterious - it’s just apache web server. Read “httpDaemon”

 

smbd - smb is short for samba services which are windows compatible shares so this would be read “smbDaemon”

This is a service meaning it is running in the background all the time.  The equivalent in windows 95/98/ME is Norton antivirus - which is not visible except in the “notification area” in the lower right hand corner - there it runs and watches all files opened, created, run etc.  It works away silently scanning and watching for viruses.

 

Now you CAN run Norton antivirus in “application mode” which means you find the icon and double click it - now you can MANUALLY run a full system scan, or change options - like schedule weekly scans etc.

But I digress, lets get back to Linux.  In Linux (and win 9x but mainly 2000 / NT )  as you gain knowledge and ambition you can start and stop services.  Why?

 

Lets say you change a configuration to your apache web server, or add a new samba (windows compatible share) you could reboot to see the effect of these change or just restart the service instead and see the effects immediately without the wasting time rebooting just to find out the change didn’t work and then have to chg again and reboot and so on.

 

Security: Shut down *things* services you don’t use.  There’s an old saying: turn off all services - now turn on only the ones you need.  This helps close doors to your system that you didn’t know were open!

date

(see tip 1st)

 

Lets you print or set the date and time.

 

Note when you set the time you ONLY enter digits no letters allowed!  Or cmd will fail.

 

**TIP: if you just want to go 1hr ahead or behind then you can do just that as a shortcut and avoid the risk of messing up the system clock which can cause problems with system processes!  BE CAREFUL on production boxes.  The stuff here is geared towards home use of Linux where there aren’t important business programs running.

 

date --set=‘+2 minutes’ <Enter>

or for daylight savings time in spring (ahead)

 

date --set=‘+1 hours’ <Enter>

TIP2: You can also run X windows (if installed) and chg the time there.

date + “%D” show me date only

 

date + “%r”  show me time only

 

 

Setting the Time/Date:

1.) date <Enter> 

#REMARK: displays current date/time in human readable format.

Mon Apr 08 10:46:04 PDT 2002 <-Sys Output

 

2.)date +%m%d%H%M%Y%S

040810462002 <--System Output

 

04=April 08= 8th 1046= 10:46am, for pm type 22:46 2002= year 2002.Note you don’t enter the time zone and seconds are optional.

3.) Now basically retype the all digits output above and just chg the item you want: ex:

040809462002 <Enter>

    ^^ 09 instead of 10 to roll back 1hr for daylight savings time.

date <Enter>, shows time and date.

 

 

 

NOTE: be careful to type all commands in the proper upper/lower case exactly as I type in the examples [unless I made a mistake :) ]

 

df (Disk space Free)

Disk space Free - To determine how much free disk space on all hard drives and file system types: ex ext2, iso9660/cdrom, etc.

-h  show the output in ez to read human format

df -h

dir

list contents of a directory

FILLIN

 

dmesg also ctrl pg/up pg/dn key

display messages that you see at the startup of Unix / Linux.

press and hold ctrl  now press either pg/up pg/down

lets you scroll the display backup any time you missed something.

 

dmesg | more <Enter> display system msg’s pg at time.  to see info about your 1st network card type:

dmesg | grep eth0 <Enter>

DOS (vfat, FAT16 or FAT32  i.e. Microsoft) Partition Access

In order to access any drive such as a: CD ROM, floppy disk, or another hard drive or partition or logical drive (extended partition) you must

-------------------------->

first login as root

make a “mount point” which is just a normal directory.  For example:

mkdir /mnt/vfat <Enter> (note vfat mounts both FAT16 and FAT32 partition types with NO Change to the command above) now mount it by typing

mount –t vfat /dev/hda1  /mnt/vfat

to set this so it mounts every time windows starts

 

echo

used to echo the contents of important “system variables” or environment variables etc.

echo $FILLIN THIS CMD LATER

 

echo –n to dress up the output of a batch file or script in Unix

echo –n 

etc/sysconfig

 

 

 

exit

Shell prompt command that logs you  off the system (if you are not x windows) or will exit you from a shell environment ex…

Tip: from ms windows open a DOS window: click start, run type command <Enter> now type command <Enter> again and you will have opened a 2nd shell.  Now type Exit <Enter> and you will be back in the first shell now type exit <Enter> to close the shell prompt or “dos window”.

from xwindows open a shell prompt or xterm window (click on the monitor icon towards the bottom left).  now type csh to enter the C shell.  now type exit <Enter> to return to the first shell, exit again will close the shell prompt or xterm window.

 

Now quit windows  to the shell only “Dos” prompt.  type exit and you will be logged off. 

 

fdisk (See cfdisk more user friendly)

NOT the Microsoft DOS fdisk but a different program that does similar things but is run from Linux or a Linux boot disk vs. ms dos.

 

 

m    - shows you all the commands available

 

p  - Great command so you can not only see all the partitions on the disk but also see what Linux considers them and how Linux label’s them: ex hda1 for the first disk and the 1st primary partition.

 

(EXERCISE GREAT CARE when running fdisk).

 

type: df<Enter> this is to discover the device name: basically it will be ‘hda’ for IDE hard drives - most home pc’s.  And ‘sda’ for SCSI or SATA Drive - most servers that you would have at work.

rem: hda = ‘s IDE hard drive 1 but if you wish to see a 2nd HD then it would be hdb and so on.  Same with SCSI sda, sdb etc.

 

 

fdisk /dev/yourharddrivetype<Enter>

 

ex.  fdisk /dev/hda <Enter>

m <Enter> - you will see all commands.

p <Enter> you now see a nice neat list of partitions and labels etc.

 

finally type: q <Enter> to quit,  note if you make a mistake and use your backspace key or delete key you may get funny characters -

to get out of the situation press and hold ctrl then hit the c key.  This will let you break out and exit the program.

File Permissions

(Also see chmod)

Unix/Linux File permissions look strange and cryptic but in reality there are a few common ones that get used most of the time.

What is "CHMOD" and what do all those numbers mean?   

 

Basically CHMOD refers to setting the access privileges for a file.

 

777: all can read/write/exec

 

755: owner can do all, group/others can read/exec

 

644: owner can read/write, group/others can read only

 

For Directories:

 

777: all can read, write, search

 

755: owner can do all, others and group can only search

Typical settings:

 

cgi scripts: 755

 

data files: 666

 

configuration files: 644 (files not updated by scripts)

 

directories: 777 (with proper permissions on files in directory)

 

chmod +777 file.txt <Enter>

find (see grep and especially locate /slocate)

searches for things like file names similar to dos dir  *.txt or dir filename.doc etc.

 

standard way: (won’t work in Linux)

find -i . -name term-paper -print

 

LINUX WAY:

find -iname *.* <Enter>

 

common mistake:

 

user’s forget to type -name followed by the filename

-name – makes the command more dos like and very useful.

TIP to search entire Hard drive don’t go to /root  type cd /

 

always case insensitive search with -i unless you really need to match case.  This is a good reason to keep most files lower case + uppercase the first letter of directories to make them stand out more.

 

“ ” quotes used with –name will let you select exact parts of file names to search for

* same a above find –name “*.txt” or “*essag*”

-atime +[number of days you choose]

-depth descend sub directories first then search the current directory – great if you are at the root directory i.e. ‘/’ then all subdir will be chked.

-mount – don’t look in mounted systems like the CDROM or floppy disk.

 

 

Ex:

 

find /etc | xargs grep "duck" 2> /dev/null

grep -s …        ^

 

find /etc | grep "duck" 2> /dev/null

           ^

Not using xargs can be bad.

 

it _will_ work, however it will only look through one file at a time.

 

using xargs allows you to use the bare minimum number of grep's as

possible.

 

say there were 1000 files, your way will launch grep 1000 times.

 

however, using xargs, grep may get executed only 10 times. (assuming

that 100 filenames will fit on the command line argument)

 

find /dir -type f | xargs grep "string" /dev/null

find /  –name “filename.*”  or

find / -iname “filename.*”  case insensitive!

 

find  / –name “*ash*”

 

find / -name “*partfilename*” | grep oot

 

find –name “*filename*”  -atime +30  \

this will find files that are 30 days old or older and will be case sensitive

 

find –iname –depth –mount “*filename*”

find -iname your-file-name <Enter> looks only in the current directory

 

find  / –iname –depth –mount “*filename*”

the slash says search the entire HD which take a LOT OF TIME so consider using locate which looks in a single file that gets updated on a regular schedule.

 

find /etc | xargs grep "duck" 2> /dev/null

 

won't get any msg’s about files you couldn't access, you might end up missing the file if u don’t have rights to it.

 

FLOPPY DISK

mtools

how to find and access a dos floppy disk in drive A:

 

mtools <Enter>   will give you a simple list of ms dos commands that you can use to access and manipulate copy delete etc dos files two and from Linux.

 

 

basically all the familiar dos commands but with an ‘m’ in front of them.

 

mread

mdir – to see a director

mcd

and so on.

Floppy Disk Drive Access

In Linux, the floppy drive is referred to as /dev/fd0

-t the file system type vfat for ms dos compatible fat 16 or fat 32.

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

free -t

same as dos mem, shows you free memory.

free -t <Enter>

 

fsck.ext2

or efsck2

 

efsck2 is used to check a Linux second extended file system

 

NOTE: YOU MUST only run this on an UNMOUNTED

partition or volume - do this by exiting all programs you are running esp. windows and typing: init 1<Enter>

then type umount /dev/yourdev+

partition <Enter>

(type df <Enter> to determine that

 

cd  / <Enter> to get to root.

File system repair aka checkdisk / check disk / scandisk for windows complete with an “automatic” hands-off mode, but different in the typical Linux way can offer many in-depth file repair options for those ranging from  medium to advanced knowledge.

 

or just fsck or e2fsck

 

fsck.ext2 /dev/hda3 or /dev/hdc1

 

TIP: type df <Enter> to see free disk space on various devices and you will probably see the device of your main root drive then can type the proper label  -> /dev/HD??  for it.

if you just type fsck.ext2 <Enter> you will just get a command options summary.

 

Don’t panic if your disk problem says NOT to just runt fsck.ext2 in “automatic” mode but rather you are directed to run in MANUAL mode.

 

Next, you must determine the IDE hard drive device name and partition name on your hard drive.

 

I used df <Enter> (Disk Free) to see free disk space on various devices and you will probably see the device of your main root drive then can type the proper label  that fsck.ext2 needs in order to scan. -> /dev/HD??  for it.

 

device

is the special file corresponding to the device (e.g. /dev/hdc1).

 

LOST AND FOUND BOX: Where do recovered  lost file or directory fragments go?

 

/lost+found/ is the name of the dir and it is located right off the root.

 

***************************************

SURE FIRE METHOD (hopefully): start up normally if you can.  login as root, type: init 1 for single user mode, in this mode you will be able to run:

umount   /dev/hda3  <Enter> and run a manual scandisk.  In  init 1 you are in single user mode and there are hardly any services running that would prevent un-mounting the root system drive.  If you get the error system is Clean you can  use -f to force the scandisk to run:

umount   -f /dev/hda3 

e2fsck -f -c -y /dev/hda3

 

NOTE: YOU MUST be in the root directory!!!!

cd  / <Enter> or you will get the error message saying  NO SUPERBLOCK or device found in something location. (search this document for more extensive info on SuperBlock)

 

type: pwd<Enter> print working directory to see what dir you are in.  remember not /root which is the root user’s personal directory but rather the file system root dir ‘/’

 

This worked on my system:

fsck.ext2 /dev/hda3

 

MY STORY:

 

Running RH Linux v 7.0 on a Pentium 166 with 64 meg of RAM for about 1 year.  The system forces a scandisk with fsck.ext2 after a predetermined number of boot’s - example 25.

 

One day the system would no longer boot past the scandisk message. I considered deleting and reinstalling Linux but I opted instead to attempt to fix the problem and learn more about the problem.

 

NOTE: fsck.ext2 is geared towards ext2 type of partitions/file system.  There is an e2fsck.ext3.  I was in a similar situation on 06-15-05 with Mandrake Linux 10.1. 

 

"bad magic number in super-block while ..."

 

The essential first step it to be sure you are at run level 1# and logged in as root.  Type init 0 <enter> and su root <enter> then run fdisk -l <enter> (lima not 1 one) this will spit a list of all partitions, even if not mounted.

 

to make repairs and get more info type fdisk /dev/hda <enter>

 

remember hda refers to the first hard drive, and hdb would be the 2nd and so on.

 

Now you may see a message that I saw that said:

 

“The number of cylinders for this disk is set to 11983.  There is nothing wrong with that, but this is larger than 1024 and could cause problems in certain setups:

1.) software that runs at boot time ...”

 

I typed m <enter> and a nice menu of choices appears letting you do a variety of things. Note you can only press a letter, not arrow, backspace, delete key etc.  If you do you get garbage characters. that’s ok press enter.

 

then I got an error when printing the partition table:

“Partition table entries are not in disk order”

 

grep

 

(See find, grep is used in combination with many other commands)

Super useful command that teams up very nicely with many other commands. A sort of search or filter command.

 

TIP: Watch out!   grep IS case sensitive.

 

TIP2: double up! 

 

history | grep cd | grep root

you can look for 2 things at once!

grep so useful it’s not funny!

take a look at this ------------->

locate  | grep messages

locate with no files after it will find all files

grep says I’ll look at that list and show you only entries that match in this case must contain the word messages

 

another time you are in a directory /etc

 you could type ls –1 –1 | grep hosts

and the hosts file will be listed.

 

ls -R -all

to search all directories for a particular file do this:

ls -R -all | grep .txt   <--- will find all .txt files.  WARNING: do no use wildcard characters with grep or quotes.  *.txt will match nothing.  instead use .txt or filename.txt type search item exactly as it will appear.

 

find /etc | xargs grep "duck" 2> /dev/null

grep -s …

 

find /dir -type f -exec grep "string" {} /dev/null \; <Enter>

 

 

 

Lets say you edited an important file but forgot the location and command line arguments you used.

history | specialfile.txt

this will show you all commands you ran in the history list that contained the filed called “specialfile.txt

 

and especially to quickly fine a service and see if it is running:

ps ax | grep sendmail

 

grep * <Enter> will give you a list of all directories in your current dir. or you can specify a dir: > grep /etc/* <Enter>

 

To search for the word duck type:

grep 'duck' /etc/* <Enter>

groups

displays the groups a given user belongs to

userid

groups root

grub (see lilo)

A multi-boot loader that can kick off Linux and other OS’s.

GRUB an alternative to LILO. GRUB now comes with many distributions and will be the default in Fedora. GRUB can boot many more OS's than LILO and is more flexible.

 

 

gunzip

gzip

Tip use windows winzip!

-v

 

gzip -v filename.tar.gz

hardware

how to run the setup wizard in DOS (Shell prompt).

FILLIN

Windows Xconfigurator (capitalize the ‘X’)

or at the beginning: LinuxConf (all lower case, I believe).

 

help

 

Also see info command which is very useful!

to find help in the Unix dos shell

command --help

 

FreeBSD Unix command for help =

command -H <Enter>

ex cp -H <Enter>

clear --help  or cd --help  or whatever command you want help on.  TIP: often you will need the more and | or “pipe” cmd command   ls --help | more

history and ! or ‘bang’

 

 

previously typed commands

 

TIP: you can set how many commands you wish the system to store by editing the following file: profile

located: /etc

HISTSIZE=1000 (default size)

(note it’s NOT HISTORY=’s but HISTSIZE=’s)  

type history then <Enter>

 

! the bang symbol followed by a # in the command list.  ( Example   !20 <Enter> )

 

!! <Enter> to repeat the last command typed.

a list of commands followed by #’s will appear.

 

to see the root user’s history file go to /root/.bash_history

located in a file called .bash_history

 

To perform a command without scrolling to it type !20 for example to run command #20.

TIP: don’t run this from the /root folder it and other commands don’t seem to get recognized there.  if your in /root type cd / <Enter> to back-out of there.  also right=  !20    wrong way ! 20  no space between the bang symbol and its argument value (the number 20 in this case).

hosts file

/etc/hosts file

static mappings for netbios names.

sample of file would look

192.168.0.106      www.fedora.com

192.168.0.106      fedora

vi /etc/hosts <Enter>

I - Interactive startup (booting Fedora)

When starting watch carefully and you will see the msg “Press I for Interactive Startup” this will let you respond [Y]es or [N]o to the system’s request whether to start each service.

Not applicable (n/a)

I corrupted the Sendmail service by forcibly shutting it down as a part of testing the kill command.  The result was that the system hung the next time I rebooted at the point of starting the sendmail service.  So I used Interactive  mode and said no to it then used ntsysv to unchk it from auto start then R & R it – Removed and Reinstalled the RPM sendmail package.

ifconfig

Equivalent to ipconfig in win NT or winipcfg in win 9x/ME.  It displays IP Cards and the addresses they currently have.

FILLIN

ifconfig | more  <Enter> to see everything if running multiple NIC cards.

/sbin/ifconfig <Enter>

Tip: Unless you are logged in as root user you must type the full path to the system file.

info

gives you extended information about a command beyond the man pages bland facts.

 

info date <Enter>

install (see rpm)

See rpm - that stands for Fedora package manager.

 

Keep in mind installing packages is not quite so easy as windows.  Some packages may fail to install be cause they rely on other modules (programs) packages etc to be present or be a certain version.  It can be easy to get frustrated.

 

 

Note you do NOT need to specify the full path. Just type rpm --install  packagename.rpm

 

and YES your package name better end in rpm and not tar and or gz.  If it has tar or gz anywhere in the name it has been zipped with tar and or gz and must be extracted first.  Search this doc for that procedure.  Often tar and gz are used together.

[root]#  rpm --install linuxconf-1.25r7-3.i386.rpm <Enter>

IP Address - Setting it for the System NIC or Network Card(s).

 

You can also start Gnome and run LinuxConf which will proof what you type for mistakes.

/etc/sysconfig/network-scripts/ifcfg-eth0

this folder contains both the IP Address for each network card - Careful the first card is numbered like in math eth0 not eth1 which would be the 2nd card if you have 2 NIC cards in your system.

 

WARNING: **

The system in no-way proofs these files for mistakes. So you can type anything - the errors will affect other services.

 

TIP: always copy a file and add _bk and the date BEFORE changing it.  This way you have a simple “UNDO” available.

This is a sample of a typical NIC Card file:

The IP addr’s info must conform to your network - don’t just copy the info below.

DEVICE=eth0
BOOTPROTO=none
IPADDR=192.168.0.2
NETMASK=255.255.255.0

ONBOOT=yes
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
GATEWAY=192.168.0.254
USERCTL=no

 

Now to restart your network reboot or type this:

 

/etc/rc.d/init.d/network restart

 

then type ifconfig eth0 <Enter> or

just ifconfig | more to see the config for all NIC's.

 

 


vi /etc/sysconfig/network-scripts/ifcfg-eth0:0

<Enter>

 

Careful - The wrong Subnet mask will cause httpd the web server to fail and SMB or Samba windows sharing service too.

 

To create an alias that a NIC with two or more IP Addresses …

use vi editor to create an a file containing the same stuff as the sample file accept the line will be chg as follows:

 

DEVICE=eth0:0  the :0 indicates a virtual IP address for the first card this way you can have an unlimited number of IP address that all point back to one physical network card.

The next alias or virtual IP would be:

DEVICE=eth0:1, DEVICE=eth0:2, and so on.

IP Addresses DNS Alternative file Use this anytime but especially if you are NOT running a DNS server or DHCP Server

How, where do I set the IP address for the Linux system and How can I add multiple IP Addresses?

 

Solution: Edit /etc/hosts file.

from any directory… type

 

vi /etc/hosts  <Enter>

Now press the insert key to begin typing, then press esc key then Ctrl ZZ to save and exit.  To exit and Not save press esc, shift+: , q! <enter>

Remember hosts is NOT a directory it’s a file in a directory called /etc.  Often files in Linux have no extension such as .sys or .txt etc.

examples:

 

IP Address    Fully Qualified Domain name   Host name

24.130.184.55   fedora.domain1.com  fedora

24.130.148.115 www.w2kmain.com   w2kmain

 

This lets you set the host address for Linux, add multiple IP’s (multihomed) and add IP address for other hosts - necessary esp. If you aren’t running a DHCP or DNS server.

kill

Kills a process or service.  However, this doesn’t work quite as simply as it might seem: you can’t just type kill <enter>

-s  the signal you wish to send to the process

-pid  where pid is the number of the process you wish to kill.

kill –s kill 1701

 

Be careful what process you kill.  You can corrupt your system. A great way to safely experiment is to run a process such as the vi editor in the background and then kill it.

 

ex:  vi  madeupfilename.txt  &  <Enter>

now type ps ax  near the bottom of the list you will see vi  madeupfilename.txt followed by a pid or process ID #

now type kill –kill 1788

1788 is just an example of a process ID or pid.  Now  run ps ax again to see if the process # is really gone or “killed”

lilo

FILLIN a lot could be said here and more will be added.

To the Rescue: Installed or reinstalled windows and now Linux won't boot.

 

Let's look at a common mishap: in this scenario you have a dual-boot Linux/Windows computer and you happily use LILO in your master boot record partition (MBR) to boot to one OS or the other. You decide to upgrade or re-install your Windows setup. Zap! There goes the MBR (Windows ALWAYS zaps the MBR when it installs even though it's unnecessary and in decidedly poor form).

Now you're in a pickle. Your Linux partition is still fine, but it's inaccessible. How do you get back into Linux in order to re-run lilo so that it can rewrite the multi-boot loader into the MBR? Why with your boot disk, of course.

 

With the Fedora boot disk, it's a piece of cake. Just insert the floppy, boot, log in as root and type lilo at the command line. Everything's back to normal.

lilo.conf

Your boot configuration file.  It contains the info for the lilo boot manager menu that appears when you first start your system. 

 

Also contains the partition that Linux is on and the hard drive.

 

Located: /etc/

Note: I made changes but there were NOT reflected after rebooting.????

 

Linux single

single user mode to start Linux if you forgot the root password

at the login prompt type

Linux single

once in type passwd root

and choose a new password.

Linux” (LIN-NUCKS)

pronounced LIN-NUCKS NOT LINE-NICKS - don’t feel bad - I said it wrong in the beginning too.

In my opinion one of the best things about getting involved in some way with Linux and the Open Source Movement is the honest Open sharing of knowledge.

 

There are many good online communities about people helping people - the world could sure use more of that!

Also, because of Linuxs' complexity and power you don’t have to horde knowledge as often happens in Information Technology departments in corporations  with Microsoft products - which are much simpler to use - so people fear losing their edge or value an thus horde knowledge and keep it to themselves.   Linux - offers you limitless ways to find places in the OS to specialize your knowledge - this makes you a valuable contributor but at the same time dependent on your fellow users in the Linux community.

linuxconf

 

Tip: At boot to chg timeout of config menu go to Configuration, boot and chg default.

 

 

There are two versions of this utility that are basically the same:

1.) runs under windows in Gnome xwindows click: Programs, System, LinuxConf

 

DOS  based configuration utility.  Is the same as the Xwindows configuration util.  Just type Click Programs, System, linuxconf <Enter> use the enter key to open up items on the tree and tab to get to the exit button.

N/A

LinuxConf <Enter>

 

This utility may seem a bit crude: it took a lot work and I read it is 80,000 lines of programming in the C++ language.

lmhosts file

/etc/samba/lmhosts file,

used by the Apache web server to determine the IP of certain static web sites most importantly a mapping between the netbios name ‘localhost’ and the default IP Address: 127.0.0.1

 

 

locate 

(Note: locate is just an alias/shortcut/or pointer to slocate).

 

WARNING: this IS case sensitive AND adds files like once a session / day to it’s database so if you make a new file it won’t appear unless ->

 

locate is like spotlight in the Mac

awesome fast file and directory search tool. That searches THE ENTIRE HARDDRIVE and any other mounted drives. ex /mnt/cdrom, etc.

 

Note: this and other utilities may fail if run while you are in the /root directory.  So always change directories

 

TIP: Fedora Linux install you must run ‘updatedb’ while logged in as root to create the catalog or Database.

And to force it to update.

best part is that you don’t have to use wildcards

 

to search for   message1.txt  message_RA-5.doc

and Rhlinux_message_system.db  all of the files can be searched for by typing:

locate Message <Enter>

no quotes are needed nor command line options etc.

 

Note you must be logged in as the root surperuser.

 

----> you force a Manual Update!

To force an immediate manual update (no matter which directory you are in) type:

./etc/cron.daily/slocate  <Enter>

 

NOTE: File index NOT updated in real time, only when a scheduled “cron job” runs every hour/day or not at all.

 

locate *.conf

 

locate -i host.conf <Enter>

 

-i ignores case matches UPPER or lowercase.

 

TIP: if you are using a new system type su root <Enter> then the root password now type updatedb <Enter> this will run for a while and either update your file database - if it is empty then trying to match files as mentioned above will not work if the database has never been created or is empty.

 

TIP2: combine it with grep to filter the results

 

locate “*moz*” | grep “Mozilla”

 

slocate host.conf <Enter> calling it directly vs. by it’s shortcut name locate which is really just a pointer:  locate->slocate

login - text or command line instead of the GUI

Often power users want to start with the text or DOS based style login not xwindows. 

key words: text login, text only login, command line login,

text logon command logon…. etc.

vi /etc/inittab and change the line that says,
"id:5:initdefault:" to read "id:3:initdefault:". Or copy it and put a ‘#’ in

Fedora tested 4/2002 works fine.

logrotate

this is one of the standard system maintenance routines. 

 

look in the /etc/cron.daily/ directory and you will see a list of daily jobs that can be modified or you could add your own routines there.  Any “job” or batchfile that you add there will automatically be run daily by the system.

Same notation for /etc/cron.weekly/ and /etc/cron.monthly/ folders.

 

lpstat

shows pending print jobs in the queue

you can kill print jobs

lpstat <Enter>

now take a job # and type lpstat lj-1756

lj-1756 is an example of a made up job #

ls (also see dir)

list or directory list

-R recursive search just like dir /s in ms dos world!  Very useful option!!!

ls –a1 | less

-1 display one file or folder per line.

B  move back

Space Bar to move forward

q to quit!!!

 

Great cmd to search for part of a file

ls -all  *ilenam* will return files called

filename, coolfilenames.doc, etc.

 

less is same as dir /p in ms  dos says show me a page at a time.

 

And finally:

 

use ls to see the date, and time, individual and group ownership of an individual file:

 

ls -all filename.txt

 

ls -R -all

search all dir’s for a file do this:

 

ls -R -all | grep .txt    ß will find all .txt files.  WARNING: do no use wildcard characters with grep or quotes.  *.txt will match nothing.  instead use .txt or filename.txt type search item exactly as it will appear.

man

FILLIN

FILLIN

 

mkbootdisk

to make a bootable system floppy disk

you can create a new boot disk by logging in as root and executing the command mkbootdisk. You need to know your kernel version and your floppy device (usually /dev/fd0). Use the uname -a  command to display your kernel version as in this example session:

my kernel is : 2.2.16-22 Aug 22, 2000.

 

mkbootdisk --device /dev/fd0 2.2.16-22

 

Note you may need to unmount you floppy disk first:

 

umount /dev/fd0 and that’s NOT UNmount but Umount - but typed all in lowercase I’m just emphasising the U vs UN.

 

Also, if your in any version of xwindows exit first then run this from the bash shell.

 

In Linux, the floppy drive is referred to as /dev/fd0.

 

uname –r  (TO Discover which Kernel version you are using)

 

mkbootdisk --device /dev/fd0 2.2.x-yy

 

Finally: Test the disk.  I tested mine and it failed with “Error 0x10” - this typically indicates a problem with the floppy disk itself (or possibly the floppy disk drive).  So I did a full format of the disk under windows then re-ran the process under Linux and test booted it and it worked fine.

 

so test yours!

more and the | or “pipe” command

lets you see output that is longer than one page just one page at a time works exact same way dos.

 

also Shift+PageUp will let you scroll backup to see previous pages.  Tip: if you do this at the start of Linux you can see all the start up screen messages.

‘|’ the pipe symbol. Read from left to right.  The output of  command on the left becomes the input for the command on the right.

 

TIP: Did you know when you use more to display one page at a time that you can use enter and space bar to scroll.

ls -all | more <Enter>

now pressing Enter again will scroll down one line at a time and pressing space bar will scroll one page at a time!

 

 

ls –help | more <Enter>

 

 

mount (see also umount - cmd to unmount)

 

mount USB device (see last column)

 

(mount point) is a directory that can be located on almost any partition or directory but normally you should go to /mnt

directory and then create a new directory such as ‘ext1dos’ for example for a ms dos logical drive in the extended partition.

mounts a device like a: hard drive, floppy drive, or CD ROM.  Windows does the same thing only behind the scenes and automatically.

 

Linux does some of this automatically but sometimes you will need to do it manually.

 

Drive Labels: (IDE Drives)

 

physical hard drive #1:

/dev/hda

 

physical hard drive #2:

/dev/hdb

 

physical hard drive #3:

/dev/hdc

 

physical hard drive #4:

/dev/hdd

(the normal limit is 4 IDE drives for a PC).

 

SCSI drives are same as above but are labeled ‘sd for SCSI drive instead of HD.

 

Partition Numbers: 1-4 are the 4 primary partition's.  4 is special because it can be designated as an extended partition (ext) and then can contain logical drives which will receive the number 5 for the 1st logical drive, 6 for the next and so on.

 

Example:

/dev/hdb2  =’s second primary partition on the second IDE drive.

 

/dev/hda5 =’s first logical drive in the extended partition on drive1.

 

To mount the floppy disk:

mount /dev/fd0 /mnt

 

Then cd to /mnt and the contents of the floppy disk will be available.

If you have a MSDOS disk that you want access to, you can use the command:

mount -t msdos /dev/fd0 /mnt

To check and see if it mounted you can cd to the directory and type 'ls' and see if the contents have changed

or type df to see a nicer list.

 

When you are done with the floppy disk, you will have to unmount it from the file system. To do this type:

umount /dev/fd0

OR

umount /mnt

Either one will successfully unmount the file system. You cannot unmount a file system while you are in the directory that the filesystem is mounted to. This will give you a device busy error. You will have to cd out of that directory before unmounting it. Note the name of the command is 'umount' and not 'unmount' -- this is often a source of frustration with new users of Linux.

Now when you cd to /mnt it should be empty.

 

Warning Experienced Users’ only!

Here’s a sample of creating then mounting a partition: Caution be careful when using fdisk that you are working with had aka the floppy disk and not your hard drive!

 

1.    bash# fdisk /dev/hda
2.    bash# mkdir /test
3.    bash# mount /dev/hda1 /test
4.    bash# ls /test
5.    You should see root-partition list like this -
6.    bin   fd    lib   mnt  proc  sbin  usr
7.    boot  dev   etc   home  lost+found  opt  root  tmp   var

 

 

Create a mount point:

mount –t vfat /dev/hda1  /mnt/vfat  <Enter>

 

mounting an extended drive:

mount -t vfat /dev/hda5 /mnt/xxx  <Enter>

 

mount floppy MS-DOS disk: (-t MS-DOS is optional, if the disk is ms dos format)

mount -t MS-DOS /dev/fd0  mnt/floppy <Enter>

 

 

TIP: type vi /etc/fstab <Enter>

Now you can view the contents of your File System Table or fstab.  Be careful, if you want to make changes make a backup copy of the file first in the same directory and don’t change the main system ext2 or swap partitions.

 

In this file you can set additional DOS partitions you might wish to use or store data on such as user home directories.

 

MOUNT USB: (tested 12/2005 on Mandrivia Linux 2006).

 

1.     start Linux and open terminal window or start with command prompt if windows not loaded.  Good method if you need to load a video driver because your kde xwindows won’t start.

2.     logon as root

3.     make a directory called USB as follows: md /mnt/USB

4.     plug-in the USB device and type dmesg which will display the system message if the system recognized the USB device.

5.     typical USB mount for 1st device, assuming you are not using a USB mouse/keyboard etc.

6.     mount -t vfat /dev/sba1 /mnt/USB <Enter> there should be no messages - error or otherwise. Note: sba1 the 1 means partition 1.

7.     type ls /mnt/USB you should see the contents of the device.

8.     if successful type cd /mnt/USB <Enter>

9.     Done, if it didn’t work type dmesg and look back and see what the device was mounted as.

 

 

mouseconfig

Run from the shell prompt to configure your mouse.

 

mouseconfig <Enter>  Use Tab to move cursor around and Enter to press button.

MySQL

Great open source Database Server. Not installed in Fedora by default.  You dnload and install it from www.MySQL.com. 

 

Note: You also NEED to dnload the client rpm also in order to run the essential mysqladmin utility.

 

 

Network card configure manually

Method to configuring your network card manually.  1 discover Linux driver name.  Ex my card is an Intel pro 100b.  the driver name is ‘eepro100’

edit /etc/modules.conf

Add the following line:

alias eth0 eepro100b

 

note this assumes you are using a PCI nic not an old ISA.  Search online for similar directions.

 

edit(create)ifcfg-eth1

 

vi /etc/sysconfig/network-scripts <Enter>

add the following:

DEVICE=eth0

IPADDR=192.168.1.1

ONBOOT=yes

 

edit:

vi /etc/sysconfig/network

NETWORKING=yes

FORWARD_IPV4=yes

 

last:

etc/rc.d/init.d/network restart <Enter>

type ifconfig eth0 <Enter>

nfs

Network File System - this is the main way Linux to Linux pc’s share or “export” files.

 

create a sample share folder ex:

 

mkdir /nfs_share <Enter>

 

edit the exports file:  vi /etc/exports <Enter>

Allow no spaces.  Any blank lines should begin with ‘#’

#

/nfs_share (rw)  <-- Best method! Simple # but insecure.

#

or by IP addr

/nfs_share 192.168.0.10()

client side mounting the remote Linux pc’s share from a Linux pc!

 

mount hostname:/nfs_share /mnt/remotepc_nfs_share <Enter>

 

See: http://www.saragossa.net/LinuxG3/ls-nfs.shtml

ntsysv (services manager run from dos/shell prompt)

List of services starting automatically, you can add or remove from the list of services which start automatically

 

vital for samba to make sure “smb” is set to start automatically each time the system starts.

path (please see “Script, how to run it!)

Setting the system path in Fedora Linux. 

 

First be aware that programs can be executed by typing there name ONLY if the directory where they are located is in the path.  This is similar to ms dos

The settings for all users are in /etc/profile, including the path stmt.

path arguments are separated by the colon.

also add the thing about making scripts from  for dummies book.

 

vi  /etc/profile

 

just follow the existing syntax if you add directories to the path or remove them.

 

WARNING: Always make a backup copy of any critical system file BEFORE you edit them!! Ex cp /etc/profile /etc/profile_bk <Enter>

 

AND: put a comment in the file you edit with the date and time you made the change and the reason!!!  This way if you look back at a system log and say hey this err message started on 2/22/2001 and look at the file you edited and see the same date you will know what “change” caused the problem!!

 

Pipe Symbol ‘|’

pipes the output that would result from typing one command like dir or fine –name “some filename” and lets it be used as the input for the next command

FILLIN A GOOD USEFUL SETUP USING REAL DEFAULT FILES

.  Example first search for all files less than 100kb in size | now pipe that output to the sort command which will sort their names alphabetically and finally | pipe that list to a text file so I can have it saved.

ps (see kill, and services also).

process?

ax

ps ax | more this will show a list of processes running one page at a time.

pwd

Print Working Directory this cmd shows the full path of where you are located the Linux prompt  only shows just the current dir name

none

pwd <Enter>

 

WARNING: be careful, Linux DOES NOT put the full path in the command prompt like dos does.  It only puts the current dir in the prompt so always type pwd to see the full path so you know where you are with out guessing!

Redirector  Symbol. ‘ > ’ (note it works in both Linux and windows in a very similar way)

Redirect output.  Why would you want to do this?

 

If you like working in windows because you know how to do get around well.  You may need to check for a file or something in Linux and want to dump a directory’s file list to a text file then move on to a -->

-->

floppy disk or over a network to windows to examine in a word processor like ms word for example.  Or make a help file like this file with out having to type the exact error message all over etc.

Example: in windows then Linux.  Each ex shows a directory list but instead of being outputted to the screen it is “redirected” or piped to

 

windows: dir > directory.txt <Enter>

to see contents: edit directory.txt <Enter>

 

Linux:  ls -all  > directory.txt <Enter>

to see contents: vi directory.txt <Enter>

Removing Linux

It is not enough to use ms dos boot disk and fdisk to delete all the Linux partitions (option 3 delete and 4 non-dos partitions) you must also fix the boot record

 

after deleting unwanted Linux partitions boot with a ms dos disk (which must contain the fdisk command) and type fdisk /mbr this means rebuild the master boot record if it still won’t boot ok then reboot from  the dos disk and type sys c:  (you will need the sys.com program copied on to the disk )

rm (delete)

Re Move file or directory

-r recursively descend into sub directories to delete files.

-f force and NEVER Prompt. Never prompting is needed more than you might realize.  Try making a directory called dir1 then make a directory inside it called dir2 so it should look like …/dir1/dir2  now type rm –rif (which is same as rm –r –i –f)

 

-d to remove directories; but forget it. It always fails for me with the error “rm: cannot unlink ‘/dir_delme’” instead just use rm –ri or rm –rif

 

-i  will prompt you before deleting good safety net

rm –d –r  /directory-name

rm –ri filename

rm -r -f  directory-name

or

rm -rf directory-name

or

rm -ri to remove file or directories and always get prompted first.

 

TIP: if your lazy and have a bad memory you might want to do this:

 

edit your alias file for a particular profile and add the ms dos equivalent (sort of)

 

alias del=’rm -r-i -f’

then you can just type del directory name.  Note additions to the alias file (location for root user is /root/.bashrc don’t become effective until after you log off /on.  or if you want to test it just type it at the command line or shell prompt and it will be effective immediately.

 

TIP: To make your aliases file available for everyone on your system do the following:

chown mrbios:mrbios aliases

chown mrbios:mrbios aliases.db

where mrbios is an ordinary user with no special access.

 

rm (del)  same as rm (remove)

delete files

 

del filename.ext  <Enter>

route

 

Route comes into play mainly when you have two or more network cards installed and active

 

(If you get a LONG PAUSE after typing this and pressing enter you probably have some invalid routes, be patient it may take a minute or so to show what routes are available.)

Beginners – Skip right over this.  This is an advanced topic and is most likely of very little use to you anyways.

 

This is an advanced command.  To really “route” between two “network” or physical (not logical) networks requires 3 pc’s, 2 hubs (which are not joined with a network cable – that is the router’s job.

And finally a Linux box/pc with 2 network cards.

 

Yes Linux can make the PC act as a Router.  Route with no arguments shows the routes that Linux currently has mapped to get IP packets from one subnet (or network) to another. 

What is shown in the example is how to add a “route” to a network or IP subnet.

 

To delete a route type the same thing as on the right to add a route but instead of –add type

 –del.

 

-n  , route –n <Enter> verify that your routes are setup correctly.

 

BEFORE THE ROUTE TAKES EFFECT: you must at least stop and restart the network card services.

 

ifconfig eth0 down

ifconfig eth1 down

then

ifconfig eth0 up

ifconfig eth1 up.

 

Often I find I need to restart Linux all together before the route really works.

 

If you try to add the same route twice you will get the error “SIOCADDRT: File Exists.” This is just telling you the route is already mapped.  Not to worry.

 

 

“route add –net 192.168.1.0  netmask 255.255.255.0 dev eth0” <Enter>

Now add a second route on the second network card.

 

“route add –net 192.168.2.0  netmask 255.255.255.0 dev eth1” <Enter>

 

Tip: type what’s “inside the quotes” but not the quotes themselves.

 

SAMPLE ROUTES (Two Network Cards installed):

 

route add –net 24.130.184.55  netmask 255.255.255.0 dev eth0

 

route add –net 24.130.184.56  netmask 255.255.255.0 dev eth1

 

 

or you can edit files to setup and chg routes:

 

/etc/sysconfig/network-scripts/ifcfg-eth0

rpm (see install)

Fedora Package Manager – Use to install, Update or remove packages from your system.

 

What IS an SRPM and why should you use it over an RPM? There are four reasons why:

 

1. The binary RPM is not available.++1(see footnote section at the bottom of this doc)

2. The RPM you try to install complains about library and dependency problems.

3. You want to make changes to the source code.

4. You want to optimize for a particular CPU.

-qa  (see a list of all packages installed and their version number)

 

(run rpm -qa | more <Enter> to find the exact pkg name so you can run the uninstall.

or better yet:

rpm -qa | more | grep -i partialpkg_name <Enter>

(-i means Case insensitive) so to uninstall MySQL…

rpm -qa | more | grep -i mysQl <Enter>  

 

-e packagename – will uninstall a package

 

-Uvh – use to upgrade a software package

ex rpm –Uvh newerapplication-2.2.i386.rpm

 

Normal Install:

rpm --install linuxconf-1.25r7-3.i386.rpm <Enter>

 

TIP: The uninstall name of a pkg

ex:  “MySQL-3.23.49a-1.i386.rpm”  is the same except you drop .i386.rpm

 

rpm -e MySQL-3.23.49a-1 <Enter> will do the job.  As always watch out for upper/lower case!  It must be exact!

 

rpm –qa

 

rpm –qa > installedpkg’s.txt  (puts output into a text file).

 

rpm –e sendmail (will uninstall sendmail pkg).

 

Going from SRPM to RPM:

rpm --rebuild newpkg-1.0.src.rpm. Where ‘newpkg-1.0.src.rpm’ is the name of your SRPM.

 

[root]# rpm -e  linuxconf-1.25r7-3.i386.rpm

error: package linuxconf-1.25r7-3.i386.rpm is not installed

 

This common error is the result of trying to uninstall a package that is NOT installed, or the uninstall is damaged.

 

The proper way to install is:

rpm --install linuxconf-1.25r7-3.i386.rpm <Enter>

samba (see Samba below)

 

(also see NFS or Network File System - which is the native UNIX file sharing method)

Also Known As SMB Services – Basically allows 2 way communications between Linux and Microsoft Windows 95, NT4, W2K.

 

Setting up Users:

 

useradd -s /bin/bash -d /home/"userid" -m

passwd "userid"

Enter Password: <pw>

 

smbpasswd -a "userid"

Enter Password: <pw>

 

search for Special “Samba Services Info” section below this table chart.

/etc/rc.d/init.d/smb restart <- Fedora

 

This restart should immediately reflect the changes you have made to the smb.conf file.

 

Note: on the windows side you will often need to close  connection in explorer to the Linux pc then reopen it.  Just refreshing the windows may cause error message that the share is no longer available.

Samba (smb)

Networking with Windows 95 and Fedora Linux

If you want to connect to win95 PC or nt4 and maybe nt5 or win2k you must setup your

 

Note the host or PC name is not set in smb.conf but rather /etc/hosts file

 

How do I see my Current Ms Windows compatible Shares from Linux?

 

Type:

 

smbclient -L hostname -U% <Enter>

 

If prompted for a password just press <Enter>

 

‘hostname’ must be replaced with the (netbios?) name of your computer.

 

Example:

smbclient -L fedora -U% <Enter>

 

N/A

 

TIP: copy this file before you edit or make changes to it.  Do so with this command

cp /etc/samba/smb.conf /etc/samba/smbbackup.conf

 

type ntsysv <Enter> and then use tab and the space bar to “check” smb and snmpd to start automatically.  Then you must click Ok to save then shutdown and restart Linux.

 

To test: samba first can you ping your IP address from Linux  ping your.IP.address.number from  the Linux box and a windows pc.

 

next on the Linux box type: 

Smbclient –L yourlinuxhostname –U% in version 7 you will probably get an “ssn” error message but some default shares should be listed like [home] and a work group called [Myshare] keep in mind it is a good idea but NOT necessary to have a DNS or netbios name server setup. search this document for

“smbclient”

shares in a file called smb.conf

sensible way to edit it is  TYPE:

 vi /etc/samba/smb.conf  <Enter> For a real quick simple start don’t change the file when you get samba services started a share will appear with the host name of your computer ex mine is fedora and a workgroup will appear in network neighborhood called  by default “myshare”.

 

FILLIN  <see sheet to walk you through setting up a Microsoft windows compatible share>

 

My Shortcut:

alias restartsmb=

'/etc/rc.d/init.d/smb restart;

 

Manual method Type:

/etc/rc.d/init.d/smb restart <Enter>

scandisk

the equivalent in Linux is called fsck.ext2 or fsck or e2fsck

 

see fsck.ext2 in this table to find out how to use it.

 

 

Scripting, how to run it!

 

equivalent to windows batch files or

*.bat  ex autoexec.bat

 

In Mac OSX / Darwin FreeBSD Unix environment the path is set in /etc/profiles file. You must use sudo if you’re not logged on as root /etc/…

 

NEVER edit this or any sys config file without making a bkup first.

 

Ex: sudo cp /etc/profile profile.bk1 <Enter>

 

then

 

sudo pico /etc/profile <Enter>  Ctrl+X to exit Y to save.

First be aware that programs can be executed by typing there name ONLY if the directory where they are located is in the systems “run path” (you can determine this by typing which madeupfilename <Enter> at the shell prompt.  The answer will say no madeupfilename in  (usr/…. Your system path will appear in the parenthesis)

 

 

TIP: before trying these examples be sure you verify and know what directory you are working in!  pwd <Enter> will print the working directory (full path).  The Linux command prompt does NOT do this like dos does.

However, in ms dos you can execute any “batch file” or program if you switch to the directory where the batch file is located.  In Linux the app will NOT execute even if you are in the directory (if that directory is not mentioned in the system Path statement) 

 

 

TIP: warning.  It is ez to be fooled by Linux if you are used to DOS.  Lets say you have a file that has been made executable in a directory called /scripts  so the full path and file name is /scripts/myscript.fff.  you test it and it works fine (it says Hello World! [echo Hello World!].  You type which myscritps.fff <Enter>  and indeed the system confirms that /scripts directory is in the system’s search path.

 

Create a disposable folder called /delme at the root, type cd /delme.  Create a script that echo’s good bye! [ echo goodbye]

 

Confirm the file/dir is not in the search path by typing which myscript.fff. now you make the script executable by typing chmod +755 myscript.fff. 

 

Now you run the script by typing myscrip.fff <Enter> the screen should say Hello World! because the system NEVER looked in the current directory for myscript.fff rather, it searched the directories listed in the system search path, completely unlike DOS which always looks in the current directory first then the search path if it doesn’t find a match.  To be sure what script you are actually runnint type ./scriptname <Enter> 

You can execute it if you preface the script or program or “batch file” with “./”  ex to run a script (text file with commands in it) called myscript.txt   type ./myscript.fff  <Enter> 

 

To make it “executable” you MUST type chmod 755 myscript.fff <Enter> this # 755 adds executable the property.  This is very important for cgi perl  scripts!! Now you can run the script from the shell prompt by typing ./myscript.fff (if you are in the same directory as the script, if you are not then you can execute it by typing the full path to the file name ex:

/scripts/myscript.fff <Enter> you do not and should not use  “./” when you are typing the full path to the file.

 

Once again this is very different from ms windows / DOS since the extension in Linux does NOT tell the system what kind of file it is as opposed to windows where a batch or script file must end in *.bat.

sendmail

Email Server for Internet Mail

When you are finished, use the m4 macro processor to generate a new sendmail.cf by executing the m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf command

 

/etc/aliases run newaliases to update sendmail.  my internal url http://rhlinux9.domain1.com

 

sendmail -d0.1 -bv root | grep SASL

/etc/mail/sendmail.mc

 

/sbin/service sendmail restart

 

 

service - start starting Stop stopping

 

see also ps

This shows the method for starting and stopping a service.

 

just type service <Enter> and you will get a short but useful list

 

--status-all will list all services and whether they are running or not

 

--full-restart

 

restart, self explanatory.

start

stop

service xinetd restart

service httpd restart <Enter>

don’t forget to type ‘service’

will restart / recycle the Apache web server (if you’re not sure if it is running see ntsysv and be sure httpd[*] has a star next to it to show that it is set to start).

 

TIP: to see a list of currently running services a page at a time type ps ax | more <Enter>

Warning: don’t just randomly pick just any service to recycle - it may corrupt or crash your system.

 

TIP2: service --status-all > runningservices.txt <Enter>

This will pipe out all the info to a text file that you can put on a floppy disk and move over to windows to email it.

setterm

(screen saver - shell prompt adj time)

Great “look and feel” preference setting cmd for your DOS shell prompts.  You can type it at cmd line or add it to a file to make the pref chg perm.

setterm <Enter> to see full list.

 

-blank is useful sets the time out to blank screen or set to never if you prefer.

 

Adding to this file did not work on my system.  What did work was simply typing the setterm command at the shell prompt / command line and pressing Enter:

 

Temporary Setting: (persists until logging out or rebooting)

setterm -blank 0 -store > /dev/tty1 <Enter>

don’t forget to reenter the command for each virtual terminal ex:

 

setterm -blank 0 -store > /dev/tty2 <Enter>

 

all the way through tty6

 

Perm Setting:

vi /etc/rc.d/rc.local <Enter>

add the following lines for each terminal:

 

setterm -blank 20 -store > /dev/tty1

and so on… through /dev/tty6

setterm -blank 0 -store > /dev/tty6

setterm -blank 10 <Enter> [0-60min are valid intervals] in one min of no activity your screen will blank.

 

Note: It mainly makes sense for home use, where you reboot daily, to edit the file so the change is permanent:

 

vi /etc/rc.d/rc.local <Enter>

add the following lines for each terminal:

 

setterm -blank 20 -store > /dev/tty1

 

NOTE: I had a problem where the terminal setting of the last entry (tty6) over-wrote all other previous settings (i.e. tty1-5) settings.

 

 

 

setup

Super valuable DOS/shell prompt config tool to run in DOS if you need to chg config settings including services - this is very important if Xwindows cannot start do to a misconfigured system.

 

setup

shell  change

How do I know what shell I am in? FILLIN

 

How I move from one shell to another and then get back?

csh – C shell

bash – Bash shell

sh – Borne Shell ?

 

sh – the prompt changes.

 

Note when you login as a “regular user” vs. a superuser like  root – you will see the command prompt change.

 

service SERVICENAME status <Enter>

 

 

at any shell prompt type csh <Enter> this puts you in the C shell.  Next type exit and you will return to whatever shell you were previously in (which could even be the c shell).  Now type sh <Enter> for the Borne ? shell…. and so on. you will notice the up and down arrow keys don’t work in the Korn shell.

 

service httpd status <Enter>

 

TIP: Type exit <Enter> once to many times and you will be logged off the system.

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