Monday, January 16, 2012

Features of Android

As android is open source and freely available to manufacturers for customization, there are no fixed hardware and software configurations. however, android itself supports the following features:
  • Storage -uses SQLite, a lightweight relational database, for data storage. 
  • Connectivity - supports GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth (includes A2DP and AVRCP), WiFi, LTE, and WiMAX.
  • Messaging - supports both SMS and MMS.
  • Web browser - based on the open-source Webkit, together with Chrome's V8 JavaScrpit engine
  • Media support - including support for the following media:H.263, H,264 (in 3GP or MP4 container), MPEG-4 SP, AMR, AMR-WB(in 3GP cotainer), AAC, HE-AAC (in MP4 or 3GP container), MP#, MIDI, ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP
  • Hardware support - Accelerometer sensor, camera, digital compass, proximitry sensor, and GPS
  • Multi-touch - supports multi-touch screens
  • Multi-tasking - supports multi-tasking applications
  • Flash support - Android 2.3 supports Flash 10.1
  • Tethering - supports sharing of internet connections as a wired/wireless hotspot

Thursday, January 5, 2012

Linux wallpaper

10 Experimental programming Language

  1. Go
  2. F#
  3. Chapel
  4. dart
  5. zimbu
  6. x10
  7. haxe
  8. opa
  9. fantom
  10. ceylon
These are then 10 cutting-edge programming languages, each of which approaches the art of software development from a fresh perspective, tackling a specific problem or a unique shortcoming of today's more popular languages. Some are mature projects, while others are in the early stages of development. Some are likely to remain obscure, but any one of them could become the breakthrough tool that changes programming for years to come -- at least, until the next batch of new languages arrives.

Sunday, January 1, 2012

How USB work in virtualbox (linux)


VirtualBox 4 seems to have the same permission problems described for Linux. If I connect an USB drive, it appears as “unavailable” in VBoxManage or grayed-out in then guest-GUI dropdown mene, no matter what filter I define in the host settings. How can I solve it?
It is a permission problem. For a quick test, start VirtualBox as root. If your USB device is not longer grayed-out, you may have the same problem. Problem could be fixed by adding group permissions to vboxusers in your Linux.
First of all you will need VirtualBox, not VirtualBox Open Source Edition (OSE). The latter version doesn’t support USB devices. And download VirtualBox 4 Oracle VM VirtualBox Extension Pack, its support for USB 2.0 devices, VirtualBox RDP and PXE boot for Intel cards.

For Ubuntu
After installing VirtualBox 4 do the following in Ubuntu:
# Go to System -> Administration.
# Scroll down to “Users and Groups”.
# Open Users and Groups
# Click “Manage Groups”.
# When the group settings menu pops up, scroll down to vboxusers. Highlight it. Click “Properties”.
# Check the box beside your user name below the part which says group members. Press OK.
# Reboot.
# Load Virtualbox, and USB should be enabled (when you added on usb device filter, now all devices are now ‘tickable’).
For Fedora
After installing VirtualBox 4 do the following in Fedora:
# Go to System Preferences.
# Scroll down to “Users and Groups”.
# Open Users and Groups
# Click “Groups”
# Click “Add Group”
# When the new group settings pops up, type “vboxusers”. Highlight it. Click “Properties”.
# Check the box beside your user name below the part which says group users. Press OK. (Now you will see that the group members is your user name)
# Reboot.
# Load Virtualbox, and USB should be enabled (when you added on usb device filter, now all devices are now ‘tickable’).

Package Management


Debian based systems (including Ubuntu) uses apt-* commands for managing packages from the command line. Let us review how to use apt-* commands to view, install, remove, or upgrade packages.
APT is acronym for Advanced Package Tool. It supports installing packages over internet (ftp or http). You can also upgrade all packages in single operations, which makes it even more attractive.
Dpkg is Debian packaging tool which can be use to install, query, uninstall packages.

You can also try GUI based or high level interface to the Debian GNU/Linux package system. Such as:
1) aptitude: It is a text-based interface to the Debian GNU/Linux package system.
2) synaptic: GUI front end for APT
Rpm based Linux package names generally end in .rpm similarly Debian package names end in .deb, for example: apache_2.2.14_i386.deb
Install software using apt
$ apt-get install {package-name}
$ apt-get install php
Remove software using apt
$ apt-get remove {package-name}
$ apt-get remove php
Remove/erase package and configuration file
$ apt-get –purge remove {package-name}
$ apt-get –purge remove php
Updating the list of packages in your sources.list
$ apt-get update
Update software using apt
$ apt-get -u upgrade
$ apt-get upgrade php
To change the list of apt mirrors
$ apt-setup
Search for package
$ apt-cache search package
show all installed and removed packages
$ dpkg -l
show install status of package
$ dpkg -l apache
Verify if package sudo is install or not
$ dpkg -l | grep -i ‘apache’
List packages related to the apache:
$ dpkg -l ‘*apache*

List files owned by the installed package

# dpkg -L apache
What package owns the file
$ dpkg -S {/path/to/file}
$ dpkg -S /bin/netstat
show status of package
$ dpkg -s {package-name}
$ dpkg -s php
show details of package
$ dpkg -p php
list relevant packages
$ apt-cache search “network security”
Find out all denyhosts packages
$ apt-cache search denyhosts
install package from a deb file
$ dpkg -i {filename}.deb
purge package
$ dpkg -P php
re-run the configure for a package
$ dpkg-reconfigure php
get the source
$ apt-get source php
config build-deps for source and install as needed
$ apt-get build-dep
install package from specific release
$ apt-get -t {release} install php
prevent name from running at bootup
$ update-rc.d -f {name} remove
upgrade the distribution
$ apt-get –u dist-upgrade
How to know what packages may be upgraded
apt-show-versions is a program that shows what packages in the system may be updated and several useful information.