tutorial 9ku

tutorial - Power saving options of the hard disk

In Linux, the hard disk can be put to sleep entirely if it is not needed or it can be run in a more economic or quieter mode. On modern laptops, you do not need to switch off the hard disks manually, because they automatically enter an economic operating mode whenever they are not needed. However, if you want to maximize power savings, test some of the following methods.

The hdparm application can be used to modify various hard disk settings. The option -y instantly switches the hard disk to the standby mode. -Y puts it to sleep. hdparm -S x causes the hard disk to be spun down after a certain period of inactivity. Replace x as follows: 0 disables this mechanism, causing the hard disk to run continuously. Values from 1 to 240 are multiplied by 5 seconds. Values from 241 to 251 correspond to 1 to 11 times 30 minutes.

Internal power saving options of the hard disk can be controlled with the option -B. Select a value from 0 to 255 for maximum saving to maximum throughput. The result depends on the hard disk used and is difficult to assess. To make a hard disk quieter, use the option -M. Select a value from 128 to 254 for quiet to fast.

Often, it is not so easy to put the hard disk to sleep. In Linux, numerous processes write to the hard disk, waking it up repeatedly. Therefore, it is important to understand how Linux handles data that needs to be written to the hard disk. First, all data is buffered in the RAM. This buffer is monitored by the pdflush daemon. When the data reaches a certain age limit or when the buffer is filled to a certain degree, the buffer content is flushed to the hard disk. The buffer size is dynamic and depends on the size of the memory and the system load. By default, pdflush is set to short intervals to achieve maximum data integrity. It checks the buffer every 5 seconds and writes the data to the hard disk. The following variables are interesting:

/proc/sys/vm/dirty_writeback_centisecs
contains the delay until a pdflush thread wakes up in hundreths of a second.

/proc/sys/vm/dirty_expire_centisecs
defines after which timeframe a dirty page should be written out latest. Default is 3000 which means 30 seconds.

/proc/sys/vm/dirty_background_ratio
maximum percentage of dirty pages until pdflush begins to write them. Default is 5%.

/proc/sys/vm/dirty_ratio
when the dirty page exceed this percentage of the total memory, processes are forced to write dirty buffers during their time slice instead of doing more writes.

Another important factor is the way active programs behave. For example, good editors regularly write hidden backups of the currently modified file to the hard disk, causing the disk to wake up. Features like this can be disabled at the expense of data integrity.

In this connection, the mail daemon postfix makes use of the variable POSTFIX_LAPTOP. If this variable is set to yes, postfix accesses the hard disk far less frequently.

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source:http://linuxpoison.blogspot.com/2008/09/13578175711152.html

tutorial - OpenSuse/Fedora/CentOS performance boost by using prelink

prelink is a program which modifies ELF shared libraries and ELF dynamically linked binaries, so that the time which dynamic linker needs for their relocation at startup significantly decreases and also due to fewer relocations the run-time memory consumption decreases too (especially number of unshareable pages). Such prelinking information is only used if all its dependent libraries have not changed since prelinking, otherwise programs are relocated normally.

Installation:
Download prelink for OpenSuSe - here
You can also search http://rpm.pbone.net for Fedora/CentOS prelink package (prelink-0.4.0-15.1)

Install it: # rpm -ivh prelink-0.4.0-15.1

Configuration:
After sucesfull installation, run the following command (you need to be root)
# prelink -avmR

This can take a long time, after completion reboot your box and feel the difference in preformance.

Then same can be applied for fedora/CentOs

source:http://linuxpoison.blogspot.com/2008/09/13578175718995.html

tutorial - How to Enable-Disable Compiz Fusion effects in openSUSE

There may be instances when you need to disable Desktop Effects (Compiz Fusion) temporarily in openSUSE.

To disable Desktop Effects temporarily,

Press + F2 and type “metacity — replace”

This should let compiz to start but disables later on. This will replace metacity as the new Window Manager.

To re-enable Desktop Effects

Press + F2 and type “compiz-manager –replace”

This will let you make compiz-manager as the Window Manager again.

source:http://linuxpoison.blogspot.com/2008/09/135781757115486.html

tutorial - PDFedit - Opensource PDF editor

PDFedit - Free editor for PDF documents. Complete editing of PDF documents is possible with PDFedit. You can change raw pdf objects (for advanced users) or use many gui functions. Functionality can be easily extended using a scripting language (ECMAScript).

Features:
    Convert PDT to XML files
    Insert pages from other PDF documents
    Save pages as image files
    Delinearize PDF files
    Extract text from PDF files
    Add text, Add text strikethrough & highlighting
    Rotate pages, Edit page metrics
    Draw lines and rectangles in the document
    Add fonts to the page

OpenSuse 11.0 user can install it using 1 click - here
Other - here

source:http://linuxpoison.blogspot.com/2008/09/135781757119652.html

tutorial - BasKet - note pad

BasKet Note Pads is an application that provides several baskets into which the user can drop all sorts of notes: rich text, links, images, sounds, files, colors, application launchers, and more.

Objects in the baskets can be edited, copied, and rearranged. This application can be used to quickly store Web objects (such as links, text, or images) or notes, and it can also help clean up a clutered desktop. It is also useful for collecting information for a report. The data in baskets can be shared with co-workers by exporting them to HTML.

OpenSuse 11.0 user can use 1 click install - here
For other, download here

source:http://linuxpoison.blogspot.com/2008/09/135781757114992.html

tutorial - Tweak Your Ubuntu The Easy Way

If you are constantly confused over the command line, and wanted to look for an easy way to tweak your Ubuntu, then Ubuntu Tweak is definitely the application for you.

Ubuntu Tweak allows you to tweak many desktop and system settings without going to the terminal. It provides a single access point for you to change some of the hidden Ubuntu settings that are not available during your default desktop installation.

UT is currently designed for Ubuntu GNOME desktop only.

Read more : http://maketecheasier.com/tweak-your-ubuntu-the-easy-way/2008/09/10/

source:http://linuxpoison.blogspot.com/2008/09/13578175711543.html

tutorial - Setup and Configuration of Opensource Media Center - Elisa

Elisa is an open source cross-platform media center connecting the Internet to an all-in-one media player.

The Elisa Media Center has many advanced features that will make your media center experience unique. It features an intuitive interface with a professional look and feel which can be easily used with a standard TV remote control.

Features:
  * Watch pictures with previews and animated slideshows
  * Watch movies and video clips
  * Browse music collection by artists or albums covers
  * Browse internet radio and picture websites
  * Media Browsing using Cover flow, Grid view, List view, Drag-and-drop
  * Audio visualization during playback
  * Supports all media formats using Gstreamer multimedia framework
  * Autodetection of media on your network that includes:
Network Drives
Rhythmbox
iTunes
Windows Mediaplayer
iPods, cameras
USB hard drives
  * Flickr integration and basic browsing
  * YouTube integration and basic browsing
  * Shoutcast integration and basic browsing
  * Remote control support
  * TouchScreen Support
  * Samba & UPnP and DAAP shares
  * Automatic updates of plugins and core
  * Themes

Installation:
OpenSuse user can use 1 click installer - here from Packman which supports openSUSE 11.0/10.3/10.2. This will download the elisa YaSt Metapackage (YMP) file and launch YaST Package manager for installation.

For Ubuntu:
Add the following line in /etc/apt/sources.list:
deb http://elisa.fluendo.com/packages gutsy main

Import the GPG key:
$ wget http://elisa.fluendo.com/packages/philn.asc -O - | sudo apt-key add -

Run:
$ sudo aptitude update

$ sudo aptitude install elisa
or:
$ sudo aptitude install elisa-extra

Setup and Configuration:
Thanks to the distro-specific packages provided by Fluendo, installation is simple for the majority of users. On launch, Elisa looks for the configuration file ~/.elisa/elisa.conf. If it does not find one (and it won't the first time you run Elisa), it creates a skeleton elisa.conf file that you can then edit in any text editor.

The important options to customize are the locations in which Elisa will look for media. The default elisa.conf specifies ./sample_data/movies, ./sample_data/music, and ./sample_data/pictures -- directories that do not even exist inside ~./elisa/.

You can add as many locations as you like. Just scroll down in the file to find each list. To configure movie directory, for example, look for the line [plugins.movies]. Beneath it is a line reading locations = ['file://./sample_data/movies/*'] -- change this to point to a directory on your own system, such as locations = ['file:///home/yourusername/movies/*']. If you have multiple directories, separate them with commas: locations = ['file:///home/yourusername/movies/*', 'file:///home/yourusername/tvshows/*'].

You are not limited to file:// URLs, either -- network shares are accessible via other standard protocols, from smb:// or nfs:// to http://. When you have made the appropriate changes to the [plugins.movies], [plugins.music], and [plugins.pictures] sections, save elisa.conf and restart Elisa.

Demo (Youtube):

source:http://linuxpoison.blogspot.com/2008/09/135781757117972.html

tutorial - How to restore GRUB with an Ubuntu Live CD

Sometimes, if an Ubuntu installation goes wrong, or a Windows bootloader overwrites MBR and doesn't recognise the Linux installation, we have to restore our GRUB bootloader

we boot the Live CD, we choose the first option and in a few minutes we have arrived at the Live CD Desktop.

So, we go : Applications --> Accessories --> Terminal

Then, we have to remember which is our Ubuntu installation partition.

In our example, it is the second one (/dev/sda2), formatted as ext3, in the first HDD of a SATA controller. We suppose that it is the second one, since, in case we have Windows that demand to be in the first partition (/dev/sda1), this one is occupied.

Now, you have to be really careful. You have to enter the right partition, instead of sda2 (unless it is the same) In the terminal :

cd /

sudo -s -H

mount -t ext3 /dev/sda2 /mnt

mount -t proc proc /mnt/proc

mount -t sysfs sys /mnt/sys

mount -o bind /dev /mnt/dev

chroot /mnt /bin/bash

And now, you are actually "running" Ubuntu within the Hard Drive but through Live CD's terminal.

Now we restore GRUB like that:

1) Restoration to MBR

grub-install /dev/sda

2) Restoration to partition (example: /dev/sda2)

grub-install /dev/sda2

In the first case (that is the most usual) you have certainly installed GRUB on MBR after you receive, in the terminal, the message that there are no errors.

After you reboot, you have your favorite bootloader restored.

source:http://linuxpoison.blogspot.com/2008/09/135781757117174.html

tutorial - Tune TCP/IP setting using sysctl

Tunable TCP settings can be found on /proc/sys/net/ipv4 . Here are the details of few of them.

tcp_keepalive_probes : Number of KEEPALIVE probes tcp sends out, until the server decides that the connection is broken.

tcp_keepalive_time : This value shows how often tcp sends out KEEPALIVE messages. The default is 7200 (2 hours).

tcp_syn_retries : Number of times initial SYNs for a TCP connection attempt will be retransmitted. This value should not be more than 255. This is only the timeout for outgoing connections.

tcp_retries1 : This defines how often an answer to a TCP connection request is retransmitted before it gives up. This is only the timeout for incoming connections.

tcp_fin_timeout : The length of time (in seconds) TCP takes to receive a final FIN before the socket is always closed. This is required to prevent DoS attacks

You can change the values by updating the files in /proc/sys/net/ipv4 or sysctl . To make it permanent add it to /etc/sysctl.conf. Below are the default values of these parameters, you can change these values to suite your requirement.

# vi /etc/sysctl
net.ipv4.tcp_fin_timeout = 60
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_time = 7200
net.ipv4.tcp_syn_retries = 5
#

source:http://linuxpoison.blogspot.com/2008/09/13578175713637.html

tutorial - openSUSE or Novell SUSE

openSUSE 11.0 is based on the Linux kernel version 2.6.25 and provides a cornucopia of features. If you choose to download the full DVD, you can expect a whopping 4.5 GBs for the iso-format file. Other options include a Live CD and over the network. The good news is that you can use a BitTorrent client to get the iso file.

So what differentiates openSUSE from Novell's other distributions, namely SUSE Linux Enterprise Desktop (SLED) and SUSE Linux Enterprise Server (SLES)? To quote from the openSUSE FAQ:

"openSUSE, created and maintained by the openSUSE project, is a stable, integrated Linux operating system that includes the latest open source packages for desktop productivity, multimedia, Web-hosting, networking infrastructure and application development. It contains everything you need to get started with Linux and is ideal for individuals who wish to use Linux on their personal workstations or to drive their home networks."

"Novell refines and enhances openSUSE to create a hardened and supported suite of enterprise Linux products suitable for data center deployments, edge server deployments, business desktops, and business infrastructure deployment."

Novell markets the SLED and SLES products at organizations looking for a fully hardened and supported Linux distribution. They also include some products that can't be shipped with the openSUSE distribution. Novell chose the GNOME desktop to base its SLED product around for a number of reasons, not the least of which was the influence of Miguel de Icaza and Nat Friedman. The Mono project is also tightly coupled with GNOME and gives Novell a strong application development and porting base to offer enterprise customers.

source:http://linuxpoison.blogspot.com/2008/09/13578175711936.html

tutorial - VLC Media player problem with Compiz

Today after log time I was running compiz under Gnome (OpenSuse 11) to impress my wife :) and fired up VLC to play a movie and oops -- VLC din't show up any video and was only playing the audio part of the movie.

So, If you are facing similar issue then follow this ....

Open VLC preference settings: Go to Settings --> Preferences

From the preference window go to Video --> Output modules and select the "Advance option" and select the video output module as "X11 Video Output" from the drop down

Save the settings and restart VLC and now you should able to see the video under compiz.

source:http://linuxpoison.blogspot.com/2008/09/13578175719566.html

tutorial - How to view Routing Table and Change your default Gateway

The netstat -nr command will provide the contents of the touting table. Networks with a gateway of 0.0.0.0 are usually directly connected to the interface. No gateway is needed to reach your own directly connected interface, so a gateway address of 0.0.0.0 seems appropriate. The route with a destination address of 0.0.0.0 is your default gateway.

Example below:

# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window irtt Iface
172.19.12.0     0.0.0.0         255.255.254.0   U         0 0          0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 eth0
0.0.0.0         172.19.12.1     0.0.0.0         UG        0 0          0 eth0

Change Your Default Gateway

you'll need to update your /etc/sysconfig/network file to reflect the change. This file is used to configure your default gateway each time Linux boots.

NETWORKING=yes
HOSTNAME=bigboy
GATEWAY=192.168.1.1

source:http://linuxpoison.blogspot.com/2008/09/135781757115595.html

tutorial - DPKG and APT-GET commands for packages (Debian/Ubuntu)

APT-GET

    * Clean up non-existent data
      # apt-get autoclean

    * Update list
      # apt-get update

    * Install/update a package
      # apt-get install

    * review dist-upgrade prior:
      # apt-get -Vsu -o Debug::pkgProblemResolver=yes dist-upgrade

    * Apply updates
      # apt-get -Vu upgrade

    * Upgrade all dependencies
      # apt-get -Vu dist-upgrade

    * Search cache
      # apt-cache search

    * Remove and purge packages
      # apt-get --purge remove

DPKG

    * Install/Update package
      # dpkg -i

    * Check listing of installed packages
      # dpkg -l **

    * file belongs to
      # dpkg --search /path/to/file

    * List of file in package
      #dpkg -L

    * Info about package
      # dpkg -s

source:http://linuxpoison.blogspot.com/2008/09/135781757110212.html

tutorial - Mac OS like Dock in openSUSE (Avant Window Navigator)

Avant Window Navigator (AWN/Awn) is a dock-like navigation bar for the linux desktop that positions itself at the bottom of the screen. It can be used to keep track of open windows and behaves like a normal window list, something like ...

Requirement:

1. your system should support Compositing (using AIGLX or XGL). In openSUSE 11.0 AIGLX compositing is enabled by default.

2. Make suere Compositing is enabled. To verify this

    # grep -i composite /etc/X11/xorg.conf
    Option       “Composite” “on”

If missing, under “Section Extensions” add the line

    Option       “Composite” “on”

So it looks as follows:

    Section “Extensions”
    Option “Composite” “on”

3. Make sure Compositing Manager is installed. Compiz, Compiz-manager, Beryl, metacity etc

Installation:

1) Got to yast --> Software Management and search for "avant" and select and install it (For this make sure you have the packman repso include)

Running and Configuration:

1) After sucessfull installation run the avant window navigator using following command
# avant-window-navigator

2) Now run the Avant manager to preferences and setting using following command
# awn-manager

3) under General tab click Bar Appearance. Select “3D look” under Look listbox.

4) under General. There is a list box for “Icon Effects”. Select your icon effect. Once selected, click referesh button to update.

5) You can select from a list of various available applets under Applets. Select the applet and click Activate.

6) Download and install the plugins from here

7) Download and install the required thems from here

8) To make the Dock appear online, add it to the system startup in GNOME here

Finally Avant in action

source:http://linuxpoison.blogspot.com/2008/09/13578175717290.html

tutorial - How to add a program/Script to Gnome Startup

Things are always simple in Linux, it's just a mater to know them to do it.

There may be a case where you want to kick start a particular application or script as soon as you login into your Gnome desktop. For example I want to run "Avant Window Navigator" every time I login into my Gnome.

Here is the way to do this....

Go to Gnome contor center by using command: gnome-control-center
This should open up the control center from where you can manage your personal desktop settings

Now go to group "System" and select "Session" this should open up the windows where all the start up applications are listed, click on "Add" to add or browser to your application or script to get executed every time you login to Gnome

source:http://linuxpoison.blogspot.com/2008/09/13578175711903.html

tutorial - Accept/Reject mails from domain using Sendmail (access.db)

The sendmail access database file can be created to accept or reject mail from selected domains.
Since "/etc/mail/access" is a database, after creating the text file, use makemap to create the database map.

# makemap hash /etc/mail/access.db < /etc/mail/access

Below is example access file

# by default we allow relaying from localhost...
localhost.localdomain           RELAY
localhost                       RELAY
127.0.0.1                       RELAY

# accept mail from PayPal
paypal.com      OK

# Reject Mail
posterclub@e.allposters.com     REJECT
posterclub@email.allposters.com REJECT
plastmarket.com                 REJECT
jr@jrtr.org                     REJECT
7b2.606@fe01.atl2.webusenet.com REJECT
mysoldpad.com                   REJECT

# Discard Mail
1and1-private-registration.com DISCARD
# forum admin mails:
fictionaluser@gmail.com         DISCARD

# Reject full mailbox
fictionaluser@linuxweblog.com ERROR:4.2.2:450 mailbox full
fictionaluser@linuxweblog.net REJECT

# Blacklist recipients
linuxweblog.net ERROR:550 That host does not accept mail

# Spam friend domains: exempt domains from dnsbl list checking
Spam:linuxweblog.org      FRIEND

# Spam friend users: exempt email users from dnsbl list checking
# example:
# Spam:user@domain.tld         FRIEND
# clients
Spam:fictionalclient@hotmail.com FRIEND

source:http://linuxpoison.blogspot.com/2008/09/1357817571538.html

tutorial - VLC media player installation on OpenSuse

First, add a new repository (installation source) in YaST (YaST2 -> Software -> Installation Sources)

Add the following Repository:

Type: HTTP / Servername: download.videolan.org /
Directory: /pub/videolan/vlc/SuSE/

Replace in the Directory above with your installed SuSE Version. Supported at this time are :

10.1
10.2
10.3
11.0

Confirm the addition.

The repository is signed with a GPG Key (gpg key C8DA93D2 fingerprint BC8D 780D E330 8581 B2E0 7085 33DE 8FB7 C8DA 93D2). Accept this key in YaST and it will warn you in case there is something suspect with the repository.
Accept everything by clicking Finish.

Installation

Go to Software Management and enter VLC in the searchbox and search for it. Select it and click Accept to install it with all it's dependencies. This might require the SUSE CD or DVD.

If you want VLC's Mozilla Plugin, you have to select the vlc-mozillaplugin manually. It does not get installed by dependencies.

source:http://linuxpoison.blogspot.com/2008/09/13578175717841.html

tutorial - Usefull 100+ Commands

   1. Schedule a queue to run at 9am on March 1st. Note: Ctrl-d to save and exit.

      $ at 9am March 1

   2. Schedule a queue to run after 5 minutes.

      $ at now +5 minutes

   3. Check any jobs pending to run, same as at -l .

      $ atq

   4. Empty out a file.

      $ cat /dev/null > /path/to/file

   5. Change directory, see also pushd and popd.

      $ cd

   6. List run level information for the service type.

      $ chkconfig --list

   7. Change owner recursively.

      $ chown -R : /path/to/directory

   8. Change shell.

      $ chsh

   9. Scan recursively for viruses.

     $ clamscan -r

10. Compare two files.

     $ cmp file1 file2

11. Copy keeping the directory structure.

      $ cp --parent /source/path /destination/path

12. Copy keeping the permissions of the user.

      $ cp -p

13. Copy recursive.

      $ cp -r

14. Copy without shell aliasing.

      $ \cp

15. List crontab for user.

      $ crontab -u -l

16. Check current date and time.

      $ date

17. Set current date and time, may need to set the hardware clock to the system time too, `man hwclock`.

      $ date -s 'Wed May 28 11:35:00 EST 2003'

18. Show disk free in human readable format.

$ df -h

19. Configure interface using DHCP protocol.

$ dhclient eth0

20. Find context differences between two files.

$ diff -c

21. Creating a patch file.

      $ diff -Naur oldDir/oldFile newDir/newFile > new_patchFile

22. Kernel buffer

      $ dmesg

23. Show disk used in human readable format.

      $ du -h /path/to/directory

24. Find files larger than 10MB.

      $ find /path/to/file -size +10000k

25. Find file permissions with setuids.

      find / $ -perm -4000 -o -perm -2000 $ -exec ls -ldb {} \;>> /tmp/suids

26. Search for world writable files and directories.

      $ find / -perm -002

27. Display information on free and used memory.

      $ free

28. Grep on word boundaries.

      grep -w

29. Count the number of mathces - similar to “wc -l”.

      $ grep -c

30. Perform timings of device reads for benchmark and comparison purposes.

      $ hdparm -t /dev/hda1

31. Set the hardware clock to the current system time.

      $ hwclock --systohc

32. check the ip address

      $ ifconfig

33. Add an ip address to eth0.

      $ ifconfig eth0:x xxx.xxx.xxx.xxx

34. Install loadable kernel module. You can also use `modprobe` to do the same.

      $ insmod

35. Displays information about your system’s CPU and I/O.

      $ iostat [ interval [ count ] ]

36. List iptables firewall rules in numeric format.

      $ iptables -L -n

37. HangUP process so it will re-read the config file.

      $ killall -HUP

38. Install the boot loader and increase verborsity.

      $ lilo -v -v

39. Query the boot map.

      $ lilo -q

40. One time boot to the named kernel.

      $ lilo -R

41. Create symbolic link to the target file or directory.

      $ ln -s

42. Configure dynamic linker run-time bindings

      $ ldconfig

43. List the IPs bound via Ensim

      $ listaliases

44. Quickly search for indexed files. Run `updatedb` to update the indexed database.

      $ locate

45. List files.

      $ ls

46. List loaded kernel modules

      $ lsmod

47. Create the access.db file database map for sendmail.

      $ makemap hash /etc/mail/access.db < /etc/mail/access

48. Create/Make a new directory.

      $ mkdir

49. Generate a random 128 character length password.

      $ mkpasswd -l 128

50. Read in the contents of your mbox (or the specified file).

      $ mail -f /var/mail/nameOfFile

51. Print the mail queue

      $ mailq

52.

      $ mailstat /path/to/procmail/log

53. Description of the hierarchy directory structure of the system

      $ man hier

54. Check the MD5 message digest.

      $ md5sum

55. Mount points check.

      $ mount

56. Provide information about your systems’ processor.

      $ mpstat [ interval [ count ] ]

57.

      $ ncftpget -R -u -p
      hostname /local_dir /remote_dir

58.

      $ netstat -a | grep -i listen

59. Will show you who is attached to what port.

      $ netstat -anpe

60.

      $ netstat -n

61. See which programs are listening on which port

      $ netstat -lnp

62. Will show you what local TCP ports are open and what programs are running on them.

      $ netstat -lntpe

63. Will show you what local UDP ports are open and what programs are running on them.

      $ netstat -lnupe

64. Run a program with modified scheduling priority. (# range between -20 to +20, negative is higher priority)

      $ nice -n # [command to nice]

65. Scan network

      $ nmap -v hostname/ip

66. Patch and keep a backup

      $ patch -p# -b < patch_file

67.

      $ ps -ecaux

68. Turn off all quotas for users and groups, verbose mode

      $ quotaoff -augv

69. Check quota for all users and groups interactively, do quotaoff first.

      $ quotacheck -augmiv

70. Turn on all quotas for users and groups

      $ quotaon -augv

71. Add host ip to route on a particular device.

      $ route add -host xxx.xxx.xxx.xxx dev eth0:x

72.

      $ rdate

73. Remove file

      $ rm

74. Remove kernel module

      $ rmmod

75. Display the routing table in numeric.

      $ route -n

76.

      $ rpm

77. Uninstall/erase package.

      $ rpm -e

78. Erase without dependency check.

      $ rpm -e --nodeps

79. List out installed rpms by date, latest on top.

      $ rpm -qa --last | less

80. Rebuild rpm database.

      $ rpm --rebuilddb

81. Find which package owns the file.

      $ rpm -qf /path/to/file
      $ rpm -q --whatprovides /path/to/file

82. Verify package.

      $ rpm -V

      or

      $ rpm -Vf /path/to/file

83. Locate documentation for the package that owns the file.

      $ rpm -qdf /path/to/file

84. Query information on package.

      $ rpm -qip

85. Query files installed by package.

      $ rpm -qlp

86. Gives list of files that will be installed/overwritten.

      $ rpm -ql

87. Will show the scripts that will be executed.

      $ rpm -q --scripts

88. Display system activity information

      $ sar

89. Print a 0 padded sequence of numbers.

      $ seq -w 1 10

90. Record eveything printed on your terminal screen.

      $ script -a

      Ctrl+D to exit out. `more ` to view.

91. Check the status of a service.

      $ service status

92. Restart after shutdown and force fsck (fsck may take a while).

      $ shutdown -rF now

93. Split a file into pieces with numeric suffixes, so it can be burnt to cds.

      $ split -d -b 640k big_input_filename.gz piece_file_prefix.gz.

      To piece it back you can `cat piece_file_prefix.gz.* > original.gz`
94. Determine if a network service binary is linked againt tcp wrapper, libwrap.a

      $ strings -f | grep hosts_access

96. how to use tar

      $ tar -cvzf fileName.tar.gz `find /file/path -mtime -1 ! -type d -print`

97.

      $ tar -xvzpf fileName.tar.gz /path/to/file.txt

98. How to use tcpdump

      $ tcpdump -i eth0 dst port 80 | more

99. System process status

      $ top

100. View the full command line.

      $ top -c

101. Create empty file of 0 byte

      $ touch

102. Similar to `which` - shows full path to the command.

      $ type

103. Check the limit of user

      $ ulimit -a

104. Check the version of kernel running

      $ uname -a

105. Update package profile with rhn

      $ up2date -p

106. Install package via up2date.

      $ up2date -i

107.

      $ uptime

108.

      $ usermod

109. Utility reports virtual memory statistics

      $ vmstat [second interval] [no. of count]

110. Show who is logged on and what they are doing.

      $ w

111. Periodically watch output of a command in full screen

      $ watch ''

112. Run and generate the apache reports using webalizer

      $ webalizer -c /path/to/webalizer.conf

113. Recursive download of a url, converting links, no parent.

      $ wget -r -k -np

114. Mirror, convert links, backup original, dynamic to html and output a “logFile”.

      $ wget -m -k -K -E -o [logFile]

115. Locate the binary, source, and manual page files for a command.

      $ whereis

116. Shows the full path of command.

      $ which

117. Show who is logged on.

      $ who

118. Yum package updates

      $ yum check-update           -- check to see what updates are needed
      $ yum info     -- show basic information about a package
      $ yum update -- update particular package

119. Control jobs:

      $ Ctrl-z   -- suspend foreground job
      $ jobs     -- list jobs
      $ bg       -- send job to background
      $ fg       -- bring job to foreground

source:http://linuxpoison.blogspot.com/2008/09/135781757118230.html

tutorial - How to Upgrade to latest Firefox on openSUSE

In order to have the latest Firefox running on your box, you need to add a repository to your system so that whenever a new version of Firefox is released we can simply upgrade it without any pain.

1) Add the Firefox repository (goto): Yast -- Software -- Software Repositories
Repository Name (A description that is meaningful to you)
Type:HTTP
Server:download.opensuse.org
Directory on Server: /repositories/mozilla/openSUSE_11.0/

click OK, then (optionally) Refresh Now, then Finish. Now, you can update Firefox the same way you update openSUSE

2) Installation
Now got to Yast -- Software -- Software Management and search for firefox

Click on "Accept" to start with the installation of Latest firefox release. After successful installation, check the firefox version to confirm

Now, whenever there is a new firefox release, just refresh the repository, search for firefox and upgrade it, easy

source:http://linuxpoison.blogspot.com/2008/09/13578175713106.html