Computer Learning, My Free Writing on Computer and Information technology

It’s an easy thing, i just want to write it on this blog as a log so that i can remember it if i need it someday.

After writing shell script file, you have to set execute permission for your file as follows:
chmod permission your-script-name

$ chmod +x your-script-name
$ chmod 755 your-script-name

While to execute the file, you have to do:

$ bash your-script-name
$ sh your-script-name
$ ./your-script-name

Tags: executing script, linux

You may use this command to downgrade firefox from version 3 to version 2,

$ sudo apt-get remove firefox-3.0 && sudo apt-get install firefox-2

The already installed plugins won’t work for firefox 2. So you have to rename your firefox settings folder to other name by executing:

$ mv .mozilla mozilla.downgrade

Tags: linux, firefox, remove, browsing

For example you have just installing a new partition using gparted, now you could do these steps to access your new partition:

$ cd /
$ sudo mkdir /data
$ sudo mount -t ext3 /dev/hda4 /data

Now you already access the new partition. If you want to check whether your new partition already mounted, use this command:

$ df -h

if you don’t want to access your partition each time your computer restarting, execute:

$ sudo cp /etc/fstab /etc/fstab.backup
$ sudo nano /etc/fstab

And add this new line on the fstab.

/dev/hda4 /data ext3 nodev,nosuid 0 2

Save the file and iexit.

What if it doesn’t work?

If anything goes wrong, you could use livecd linux and copy fstab.backup that you have backuped by executing

$ sudo mv /etc/fstab.backup /etc/fstab

Tags: fstab, linux, new partition, gparted

For example you have just execute a command on Linux’s CLI. And since the command contains sensitive information, you have to delete it from the commands’ history.

You can use the command:

history -d number_of_the_comment

For example you access a command #history to display the commands’ history on your Linux engine.

# history
1 rpm -ivh bla..bla..bla..
2 mpg123 file1.mp3
3 mail people@secret_website.com
4 history

To delete the mail command, you can use

history -d 3 [click enter]

Tags: linux learning, linux command

These are the specifications of Acer 4520

• AMD Turion 64?2 TL-58
• VGA NVIDIA GeForce 7000M
• HDD 80GB
• WLAN atheros AR5006EG 802.11 b/g
• Acer Crystal Eye webcam

When ubuntu first installed, the VGA can only support the safe graphic mode and the sound card cannot performs. Luckily there are methods to fix this thing.

1. Insert Ubuntu’s CD (all version, you may use Xubuntu, ubuntu, edubuntu, etc)
2. choose Save graphic mode
3. Install as usual
4. configure APT so to enable repository DVD’s based instasllation , but if you have internet connection, then you don’t have to configure it
5. Install these packages
   1. nvidia-glx-new (VGA)
   2. linux-restricted-modules (sound card)
   3. linux-backports-modules (sound card)
   4. ndiswrapper-common (Atheros wifi)
   5. ndisgtk (Atheros wifi visual)
   6. ndiswrapper-utils-1.9 (dependency
      ndisgtk)
   7. cheese (webcam)
6. Download the driver net5211.inf (the Win XP version not the Vista version) , you can search via Google, the file usually archieved
7. extract the archieved driver
8. Execute this programs

    # ndiswrapper -i net5211.inf
   
   # ndiswrapper -l //make sure the device status is present
   
   # ndiswrapper -m //make sure the latest line shows wlan0 alias
   
   # ndiswrapper -ma
   
   # loadndisdriver

9. Configure sound

   //sound configuration
   
   nano /etc/modprobe.d/alsa-based //add text below on the last line.
   
   options snd-hda-intel model=acer

10. Save/CTRL + X
11. Click System > Administrator > Restricted Driver Manager
12. Enable VGA Driver
13. Restart your PC

PS: There are some laptops that use broadcomm WIFI instead of antheros, so install the driver:

#apt-get install bcm43xx-fwcutter

restart without installing ndiswrapper.
Tags: Linux and Open Source, Linux, Acer 4520

Many RM files in Linux can’t be played using Real Player due to some unknown reasons, Try to use VLC if you face this problem.

PS:

1. But VLC can’t be used to play the RMVB (real media video bitrate).

2. To play RMVB, you could install Real Media for Linux.

3. RM video can also played using MPlayer.

related article: how to install Real Media for Linux