Ubuntu Guide

ssh to remote host without password

admin — Wed, 10 Mar 2010 03:52:13 +0000

By default we need type remote user’s password to access to remote host with ssh command.This tutorial shows how to configure to access remote host without password.

First,assume:

local host:192.168.1.100
remote host:192.168.1.101,username:username
we want to access to username@192.168.1.101 from 192.168.1.100 without password using ssh

1.Open terminal in 192.168.1.100 machine and type:

ssh-keygen

just press Enter to finish this command and it will create plublic/private rsa key pair:id_rsa,id_rsa.pub

2.Create .ssh directory in remote host which we want to access to.For security,change the permission to 700.
use ssh to access to remote host:

ssh 192.168.1.101 -l username

create .ssh directory and change it’s permission:

mkdir .ssh
chmod 700 .ssh

3.copy and paste id_rsa.pub file from localhost to remote host’s .ssh folder and rename to authorized_keys

scp .ssh/id_rsa.pub username@192.168.1.101:/home/username/.ssh/authorized_keys

Now,use ssh command to access to username@192.168.1.101 from 192.168.1.100 and it won’t ask for password again.
In addition,if it outputs:Agent admitted failure to sign using the key.Try ps -Af|agent to make sure ssh-agent has started.If not,start it and add id_rsa :

ssh-agent
ssh-add id_rsa

GPRename-A complete batch renamer for files and directories(GUI)

admin — Mon, 08 Mar 2010 03:46:26 +0000

GPRename is a GUI tool based on gtk2-perl in Linux.It can easily rename multiple files or folders,it supports change filename in lowercase/uppercase,insert remove or replace letters in filename include the extension,change filename to number.

Install GPRename in Ubuntu

Just search gprename in System->Administration->Synaptic Package Manager
Or open terminal from Applications->Accessories menu,and type this command to install GPRename:

sudo apt-get install gprename

Now,you can launch GPRename from Applications->Accessories menu or by type gprename command.

In the left,choose a directory and in bottom do what you want to change with these files/folders in this directory.Click Preview and preview the changes in right box->New Name.Finally click Rename button to do the change.

GPRename source page:http://gprename.sourceforge.net/

Couple of amusing linux commands

admin — Sat, 06 Mar 2010 14:38:45 +0000

Today I found this in ubuntu forums,although it could be a long time ago I had to share it with you!

Easter Egg
Open terminal from Applications->Accessories->Terminal.Type these command in turns:

apt-get moo
aptitude moo
aptitude -v moo
aptitude -vv moo
aptitude -vvv moo
aptitude -vvvv moo
aptitude -vvvvv moo
aptitude -vvvvvv moo

Enjoy the output!If you have install apt-build(use sudo apt-get install apt-build),you could also type:

apt-build moo

cal 9 1752
We know,cal month year prints the calendar.But

cal 9 1752

Outputs:

September 1752
Su Mo Tu We Th Fr Sa
1 2 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

Here is the reason:

Britain and the British Empire (including the eastern part of what is now the United States) adopted the Gregorian calendar in 1752 (see the Calendar (New Style) Act 1750) by which time it was necessary to correct by 11 days. Wednesday, 2 September 1752 was followed by Thursday, 14 September 1752 to account for 29 February 1700 (Julian). After 1753, the British tax year in Britain continued to operate on the Julian calendar and began on 5 April, which was the “Old Style” new tax year of 25 March. A 12th skipped Julian leap day in 1800 changed its start to 6 April. It was not changed when a 13th Julian leap day was skipped in 1900, so the tax year in the United Kingdom still begins on 6 April.(from:http://en.wikipedia.org/wiki/Gregorian_calendar)

Next command is :

fortune

it may prints famous quotation,or something humourous and it prints different in each fortune command.
If you installed fortune-zh(sudo apt-get install fortune-zh),it can even prints Tang poem Song jambic verse .Of course,you’d first make your system support printing Chinese language.

Try other amusing commands:

yes
ddate
xeyes
cowsay (sudo apt-get install cowsay)
cowthink

Remmina-free and open-source Remote Desktop Client written in GTK+

admin — Thu, 04 Mar 2010 03:47:26 +0000

Remmina is a remote desktop client written in GTK+, aiming to be useful for system administrators and travellers, who need to work with lots of remote computers in front of either large monitors or tiny netbooks.Remmina supports multiple network protocols in an integrated and consistant user interface. Currently RDP, VNC, XDMCP and SSH are supported.
Remmina is free and open-source software, released under GNU GPL license.Currently,the latest version Remmina 0.7.4 released on February 18, 2010.
Install in Ubuntu

Add Remmina PPA by editing /etc/apt/sources.list with this command (or open system->Administration->Software Sources and add Remmina PPA source.)

sudo gedit /etc/apt/sources.list

append this line into the end of the file:
for 9.10:

deb http://ppa.launchpad.net/llyzs/ppa/ubuntu karmic main

for 9.04:

deb http://ppa.launchpad.net/llyzs/ppa/ubuntu jaunty main

Add the key and update:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 5A0FA8F1
sudo apt-get update

Now,there should be three packages in ubuntu repository:
* “remmina”, the main GTK+ application
* “remmina-gnome”, the GNOME desktop applet
* “remmina-xfce”, the Xfce panel plugin
Install them from synaptic package manager,or use the sudo apt-get install packagename command to install them.

Remmina mainpage:http://remmina.sourceforge.net/index.shtml

Screenshots (from Remmina mainpage)

Ubuntu Tweak 0.5.2 Release and upgrade/download link included

admin — Tue, 02 Mar 2010 04:20:14 +0000

Ubuntu Tweak has released a new version 0.5.2.This release has a few bug fixed and friendly improvment.
Since version 0.5 brought “Application Center” and “Source Center” with synchronizing function,user can easily get more fresh softwares.Despite user always didn’t know what has updated after every sync.
So Ubuntu Tweak 0.5.2 add new item highlight in App and Source Center.
Bug fixed:
Ubuntu Tweak > System menu > Nautilus options
Python bug during startup
Cancel button won’t work when choosing a new GNOME menu logo icon
Crashes on choosing window manager configuration
Metacity reports error with: ‘NoneType’ object has no attribute ‘replace’
typo in LockDown.py
typo in nautilus.py

Download/Upgrade to this new version

Download deb or source package from:https://launchpad.net/ubuntu-tweak/0.5.x/0.5.2

If you have add the PPA source and installed an old Ubuntu-Tweak version,you can check and upgrade from Update-Manager (System->Administration->Update Manager).Or,use this command to install all available updates:

sudo apt-get upgrade

Add medibuntu sources to install more useful softwares in Ubuntu

admin — Thu, 25 Feb 2010 03:37:12 +0000

This tutorial shows how to add medibuntu to ubuntu sources that makes your ubuntu can available more free softwares.
By now,medibuntu includes following binary packages:
# aacgain
# aacplusenc
# acroread-fonts
# alsa-firmware
# amrnb
# amrwb
# app-install-data-medibuntu
# apport-hooks-medibuntu
# gizmo5
# googleearth-data
# googleearth
# hot-babe
# ices
# libamrnb3
# libamrnb-dev
# libamrwb3
# libamrwb-dev
# libavcodec-extra-52
# libavcodec-unstripped-52
# libavdevice-extra-52
# libavdevice-unstripped-52
# libavfilter-extra-0
# libavfilter-unstripped-0
# libavformat-extra-52
# libavformat-unstripped-52
# libavutil-extra-49
# libavutil-unstripped-49
# libdvdcss2
# libdvdcss-dev
# libpostproc-extra-51
# libpostproc-unstripped-51
# libswscale-extra-0
# libswscale-unstripped-0
# medibuntu-keyring
# non-free-codecs
# realplayer
# rmconverter
# w32codecs
# w64codecs

Step1:Edit /etc/apt/sources.list file by this command (open terminal from Applications->Accessories->Terminal to type command):

gksudo gedit /etc/apt/sources.list

append following code into the end of the file(for ubuntu9.10):

deb http://packages.medibuntu.org/ karmic free non-free

change karmic(ubuntu 9.10)in previous code to hardy/intrepid/jaunty/lucid(ubuntu 8.04/8.10/9.04/10.04).

Step2:Use this command to add GPG key:

sudo apt-get install medibuntu-keyring

update your system:

sudo apt-get update

Done.Now,you can install the packages list in the top by apt-get install command or from synaptic package manager

Tomfox-firefox addon to Create Tomboy notes from Firefox

admin — Thu, 25 Feb 2010 02:59:57 +0000

You may want to note something useful with Tomboy when you’re browsing the web,it is inconvenient to copy and paste again and again.
Tomfox is a firefox addon that adds a “Create Tomboy Note” option to the right click menu. Users can send a selected piece of text to a Tomboy note directly from within Firefox.

Get Tomfox:https://addons.mozilla.org/en-US/firefox/addon/8276

Tomfox also provides several useful options and you can get them from preferences windows:

Tile windows vertically/horizontally in Ubuntu easily with X-Tile

admin — Tue, 23 Feb 2010 04:58:45 +0000

When you are operating on several windows and want to do some compared things,it is convenient to quat tile windows,or tile windows vertically/horizontally with keyboard shortcuts.
X-tile is a gnome applet for your panel (or optionally a standalone application)that allows you to select a number of windows and tile them in different ways.
This is especially useful for comparing products in separate web pages,or for programmers refering to documentation as they are programming.

Install X-tile

Download the deb package and double click to install.
x-tile_1.3.1-1_all.deb
You’d better to use this command to install X-tile(open terminal from Applications->Accessories menu to type command),because it may prompts you to install some dependences.

sudo dpkg -i x-tile_1.3.1-1_all.deb

When I first install x-tile,I need to install python-psutil by following command and then run previous command to install again.

sudo apt-get install python-psutil

Create keyboard shortcuts to quick tile windows in different ways

After installation,you can do this tile things with GUI by open X-tile from Applications->Accessories menu.

However,it’d better to create shortcuts rather than click icons.
Go to System->Preferences->Keyboard shortcuts to open following screen.Click Add,type a name as you like and type following commands:

x-tile –tile-all-vertically (skip main window, directly tile all opened windows vertically)
x-tile –tile-all-horizontally (skip main window, directly tile all opened windows horizontally)
x-tile –tile-all-quad (skip main window, directly quad tile all opened windows)
x-tile –maximize-all (skip main window, directly maximize all opened windows)

In the screen,I create 4 shortcuts.Single click on right of the highlight line and set its key combination.

More:http://open.vitaminap.it/en/x_tile.htm

How to reset forgotten user/boot password in Ubuntu

admin — Mon, 22 Feb 2010 02:33:32 +0000

If you forgot your ubuntu user password,or you have enabled root user and forgot the password,you can try following to reset the forgotten password.

First,start your machine and when it boots into grub menu,select “Ubuntu GNU Linux …. (recovery mode)” (just use up/down arrow key to highlight it,not press enter).

Press E to get into edit screen,there find ro single and change it into rw single init=/bin/bash,then press Ctrl+x or b to boot into a command line.

type following command:

mount -a
 
passwd your-user-name

it will prompts to input new password.If you want to reset the root password,change the second command to passwd root.
Now,restart and login with the new password.

How to view PDF files online in Firefox on Ubuntu 9.10(Karmic)

admin — Mon, 22 Feb 2010 01:45:47 +0000

In Ubuntu PDF files by default are opened in a separate PDF viewer.However,it would be better to view the online PDF files in web browser.Following shows how to get online PDF embedded within the Firefox window.

First,open terminal from Application->Accessories->Terminal to type this command to install Mozplugger and Evince:

sudo apt-get install evince mozplugger

Edit the Mozplugger config file by:

gksudo gedit /etc/mozpluggerrc

find out following section:

application/pdf:pdf:PDF file
application/x-pdf:pdf:PDF file
text/pdf:pdf:PDF file
text/x-pdf:pdf:PDF file
ACROREAD()
repeat noisy swallow(kpdf) fill: kpdf “$file”
repeat noisy swallow(Xpdf) fill: xpdf -g +9000+9000 “$file”
repeat noisy swallow(okular) fill: okular “$file”
GV()
repeat noisy fill exits: evince “$file”

replace above with following code if you want to use xpdf PDF viewer within the Firefox:

application/pdf:pdf:PDF file
application/x-pdf:pdf:PDF file
text/pdf:pdf:PDF file
text/x-pdf:pdf:PDF file
repeat noisy swallow(Xpdf) fill: xpdf “$file”
ACROREAD()
repeat noisy swallow(kpdf) fill: kpdf “$file”
repeat noisy swallow(okular) fill: okular “$file”
GV()
repeat noisy fill exits: xpdf “$file”

Or if you would like the Evince PDF viewer replace with this:

application/pdf:pdf:PDF file
application/x-pdf:pdf:PDF file
text/pdf:pdf:PDF file
text/x-pdf:pdf:PDF file
repeat noisy swallow(evince) fill: evince “$file”
ACROREAD()
repeat noisy swallow(kpdf) fill: kpdf “$file”
repeat noisy swallow(Xpdf) fill: xpdf -g +9000+9000 “$file”
repeat noisy swallow(okular) fill: okular “$file”
GV()
repeat noisy fill exits: evince “$file”

Close and save changes.Logout and back in,then open Firefox and try to view a PDF file.
Original text:http://sprayfly.com/2010/01/15/view-pdf-files-inline-in-firefox-on-ubuntu-karmic-9-10/