In an earlier post, I mentioned about the Runlevels in Ubuntu and how its different from the rest of the Linux family. Each Runlevel can be configured to start with certain services. A tool to manage the Services in Ubuntu is sysv-rc-config
This tool can be installed using the command:
sudo apt-get install sysv-rc-conf
Once installed, it can be used as:
This tool will display all the services and the runlevels. You can easily choose which services to load and which not to. The screenshot shows how it will appear. To exit the tool, press q key.
Although I am not a fan of Internet Explorer but sometimes it cannot be ignored especially when few websites have limited their access to IE browsers only or some old websites with poor markup which only renders on IE.
Internet Explorer (IE 5, 5.5, 6 and 7) can be installed and run on any Linux distribution. The package can be found and downloaded from these links:
When installing IEs4Linux, the Linux X-Window may crash, giving you the following error message:
The program ‘ies4linux-gtk.py’ received an X Window System error.
This probably reflects a bug in the program.
The error was ‘RenderBadPicture (invalid Picture parameter)’.
(Details: serial 5546 error_code 158 request_code 148 minor_code 7)
(Note to programmers: normally, X errors are reported asynchronously;
that is, you will receive the error a while after causing it.
To debug your program, run it with the –sync command line
option to change this behavior. You can then get a meaningful
backtrace from your debugger if you break on the gdk_x_error() function.)
The workaround this is to use the non-GUI, command based installation. To install use the command:
For further help:
I hope the day comes when all of this is not required and we have a true cross-browser web.
When we download video from Youtube or any other website, 90% chances are you are watching them using Flash Video Player whose format is FLV. Some of the videos uploaded in Youtube are sliced into multiple parts especially when Youtube only allowed you to upload a video of maximum 10 minute duration.
There is a simple but useful way of joining these files into a single under Ubuntu.
First you will need to install the package:
sudo apt-get install avidemux
Next, keeping the audio/video encoding unchanged, just join them (change the filenames accordingly):
Sometimes Google Chrome under Linux or Ubuntu gives the following error:
Your preferences can not be read.
Some features may be unavailable and changes to preferences won’t be saved.
This is because the owner of the following files have been changed for some unknown reason:
Under /home/[user]/.config/google-chrome/ the file Locale State and under /home/[user]/.config/google-chrome/Default the file Preferences.
Note: This tip works for Linux, for Windows the steps have not been personally tested.
If you are using Windows XP:
C:\Documents and Settings\[Username]\Local Settings\Application Data\Google\Chrome\User Data\Default
Mounting ISO files in Linux is quite straight forward and simple e.g. using the mounter function in Ubuntu straight from the context menu or by using a command line like this:
mount -o loop image.iso /mnt
Anyway mounting BIN/CUE image files is not that straight forward as they’ll need conversion to ISO before mounting, however the process is quite simple, but it need a small application called bchunk. The bchunk package contains a UNIX/C rewrite of the BinChunker program. It converts a CD image in a .bin/.cue format (sometimes .raw/.cue) into a set of .iso and .cdr/.wav tracks. The .bin/.cue format is used by some non-UNIX CD-writing software, but is not supported on most other CD-writing programs.
Runlevel is the mode in which the operating system like Linux is running. Conventionally, seven runlevels from 0 to 6 existed. Where 0 meant shutdown and 6 meant Reboot.
In previous versions, Ubuntu used to the /etc/inittab file to manage runlevels, just like most of the Linux distributions. This file was based on traditional init daemon, which is used to perform system startup tasks. This was replaced in Ubuntu 6.10 (Release date: 26th-Oct-2006) with Upstart, an event based daemon. Now there are several files under the /etc/events.d/ directory.
Normally, a system can not communicate with another system belonging to a different network address. IP forwarding is the mechanism of forwarding an IP packet from one network (example: 192.168.1.0) to another network (example: 192.168.2.0).
How to enable IP Forwarding in Linux?
By default, IP forwarding is disabled in linux. The current setting can be verfied using the command:
This will give the output: 0
Another way to test is to run:
This will give the output:
net.ipv4.ip_forward = 0
Where 0 means disabled and 1 means enabled.
Enabling IP Forwarding for the Current Running Kernel
Running either of commands will perform the task:
sysctl -w net.ipv4.ip_forward = 1
echo 1 > /proc/sys/net/ipv4/ip_forward
But this is only for the current running kernel session. After reboot the old values will be restored.
Permanently Enabling IP Forwarding
Open the required in VIM or any other text editor:
Locate the line and modify it as under:
net.ipv4.ip_forward = 1
But these changes will not take effect unless the system is restarted or the command is run:
sysctl -p /etc/sysctll.conf
For Redhat systems, restarting the network service will automatically reload the changes to sysctl.conf:
service network restart
On Ubuntu, this is also possible by restarting the procps service:
For Debian distributions open the /etc/network/options and make the following changes and restart the network service or reboot:
ip_forward = yes
For Redhat distribution open /etc/sysconfig/network and do the same:
FORWARD_IPV4 = true
The changes can be viewed using the commands mentioned above.