Now this is a realy really awesome tool by Facebook itself. You can access it here:
http://www.facebook.com/friends/edit/?sk=phonebook
To make it specific, if you are logged into your Facebook Account, you can visit the above page to take you to the Telephone directory of your friends. To test you can Click to Get Facebook Friends Telephone Directory
You can print this too ;)
Showing posts with label discussions for IT People. Show all posts
Showing posts with label discussions for IT People. Show all posts
Wednesday, July 13, 2011
Wednesday, July 6, 2011
Terminal (Shell) on Mac OSX or Unix continues to show a folder even if it is deleted or renamed
I have logged this defect with Apple. But since then I have only been told it is legacy Unix behavior. And Unix is supposed to behave that way. In any case, I find it valuable to share this now.
-------------------------------------------------------------
This is already present on Apple Website since 19th March 2010 and has one response in addition to the emails. Read Further Apple Mac OSX Bug By Anwar Faiz.
-------------------------------------------------------------
Make a folder, let us say "xyz" on desktop and cd to this location on a terminal using 'cd' command.
Now rename that folder to "abc".
Now type 'ls' command on Terminal to see the content of folder "xyz", it still shows.
In addition if you use 'pwd' command, it still shows that you are in directory "xyz"
Worse is that even if you delete the folder "xyz" and empty trash. Even then using 'pwd' command would show your present working directory as "xyz" folder.
--------------------------------------------------------------
I got a detailed response for this. The same can be read over at same Apple Official website also. I am thankful to Mr. Bob Harris from New England, USA, who took time to explain.:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All expected behavior.
The 'cd' command makes a chdir() system service call, which opens the target directory and stores the open file descriptor in the process.
When you rename the folder, that just changes the directory entry in its parent folder, it does not change the file system inode for the directory nor does it affect already open file descriptors to the directory.
So when you do an 'ls' with no path, the 'ls' command will ask the file system for the '.' (current directory), which the file systems knows to use the current working directory it already has saved in the process.
This is how Unix has worked forever.
'cd' and 'pwd' are bash built-in commands, so bash has cached the last 'cd' path, and when you issue 'pwd', bash just echos the cached path information. It does not verify anything before displaying the path.
If you want to see the real current path, then try using
/bin/pwd
this will do the more complex reverse path reconstruction, which can have some unexpected responses, because of symbolic and hard links that may have been used to navigate down to the current directory location.
Worse is that even if you delete the folder "xyz" and empty trash. Even then using 'pwd' command would show your present working directory as "xyz" folder.
Again, bash is just echoing the cached path that bash last knew about.
Also since the process still has an open file descriptor to the directory open in the process as the current working directory, the file system will defer the actual directory delete until after that file descriptor is closed.
The fact that a file or directory will not be truely deleted if it is still open, allows an application to continue to use a file if it has it open, even when some other process deletes the file. This can be good for the application, but if that was a huge file and you were trying to free up space, you would not see the space returned until after the process that has the file open, closes the file.
You can use the 'lsof' command to find what processes have what files/directories open.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In addition, it was advised that, if I have additional Unix or Terminal related questions it would be best to post them in the Mac OS X Technologies > Unix Forum. So, one place where you can also redirect yourself for taking other unix Vodka Shots is Apple Unix Discussions
-------------------------------------------------------------
This is already present on Apple Website since 19th March 2010 and has one response in addition to the emails. Read Further Apple Mac OSX Bug By Anwar Faiz.
-------------------------------------------------------------
Make a folder, let us say "xyz" on desktop and cd to this location on a terminal using 'cd' command.
Now rename that folder to "abc".
Now type 'ls' command on Terminal to see the content of folder "xyz", it still shows.
In addition if you use 'pwd' command, it still shows that you are in directory "xyz"
Worse is that even if you delete the folder "xyz" and empty trash. Even then using 'pwd' command would show your present working directory as "xyz" folder.
--------------------------------------------------------------
I got a detailed response for this. The same can be read over at same Apple Official website also. I am thankful to Mr. Bob Harris from New England, USA, who took time to explain.:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All expected behavior.
The 'cd' command makes a chdir() system service call, which opens the target directory and stores the open file descriptor in the process.
When you rename the folder, that just changes the directory entry in its parent folder, it does not change the file system inode for the directory nor does it affect already open file descriptors to the directory.
So when you do an 'ls' with no path, the 'ls' command will ask the file system for the '.' (current directory), which the file systems knows to use the current working directory it already has saved in the process.
This is how Unix has worked forever.
'cd' and 'pwd' are bash built-in commands, so bash has cached the last 'cd' path, and when you issue 'pwd', bash just echos the cached path information. It does not verify anything before displaying the path.
If you want to see the real current path, then try using
/bin/pwd
this will do the more complex reverse path reconstruction, which can have some unexpected responses, because of symbolic and hard links that may have been used to navigate down to the current directory location.
Worse is that even if you delete the folder "xyz" and empty trash. Even then using 'pwd' command would show your present working directory as "xyz" folder.
Again, bash is just echoing the cached path that bash last knew about.
Also since the process still has an open file descriptor to the directory open in the process as the current working directory, the file system will defer the actual directory delete until after that file descriptor is closed.
The fact that a file or directory will not be truely deleted if it is still open, allows an application to continue to use a file if it has it open, even when some other process deletes the file. This can be good for the application, but if that was a huge file and you were trying to free up space, you would not see the space returned until after the process that has the file open, closes the file.
You can use the 'lsof' command to find what processes have what files/directories open.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In addition, it was advised that, if I have additional Unix or Terminal related questions it would be best to post them in the Mac OS X Technologies > Unix Forum. So, one place where you can also redirect yourself for taking other unix Vodka Shots is Apple Unix Discussions
Thursday, June 16, 2011
Free National Aptitude Test Talenthunt 2011
Hi,
I came across a link www.nationaltalenthunt.com conducting a Free
National Aptitude Test on Sept 4, 2011. If it interest anyone, he/she may visit
the site. Please be advised that I have no relation with the aforementioned organization and have not tested any credibilty or quality of test.
Just wanted to pass the info.
I came across a link www.nationaltalenthunt.com conducting a Free
National Aptitude Test on Sept 4, 2011. If it interest anyone, he/she may visit
the site. Please be advised that I have no relation with the aforementioned organization and have not tested any credibilty or quality of test.
Just wanted to pass the info.
Friday, October 22, 2010
DOS and DDOS: An article on Hacking using Denial of Service Attacks
A very common term in the field of hacking and Security is DoS Attack. Hackers employ a number of techniques to attack and disrupt computer systems and networks. There is an important point here, to understand the two flavors of DOS attacks. Attacks can be of different types depending on the aim and speciality of the attacker. Some just want to disrupt computer systems but there are some hackers who intend to infiltrate the computers and steal sensitive information for drastic and really crazy purposes.
DOS or Denial of Service attack: This is a common way to attack a computer network. The main intention of a DOS attack is to disrupt the activities of the server through overloading it with unwanted requests. The attacker usually sends large number of requests to the server which leads to overloading. When the server gets overloaded, it is unable to answer to normal requests. DOS attacks are usually directed at websites. It is very easy to prevent and stop DOS attacks. In very plain words it should be noted that DOS attack if properly done can bring server on knees. Users and some scripts and functions would be starved of some services. These services may be among some of the crucial ones.
As said on the Symantec Website:
“ DoS is a Denial of Service to a victim trying to access a resource. In many cases it can be safey said that the attack requires a protocol flaw as well as some kind of network amplification.
Denial of Services is also an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services through the the consumption of bandwidth of the victim network, or the overloading the computational resources of the victim system.
The motivation for DoS attacks is not to break into a system. Instead, it is to deny the legitimate use of the system or network to others who need its services. One can say that this will typically happen through one of the following means:
1. Crashing the system.
2. Deny communication between systems.
3. Bring the network or the system down or have it operate at a reduced speed which affects productivity.
4. Hang the system, which is more dangerous than crashing since there is no automatic reboot. Productivity can be disrupted indefinitely.”
There is yet another but more advanced form of denial of service attack. Here, a large number of zombie computers are used to send requests to the server which is being attacked. This is popularly known as DDOS or Distributed Denial of Service Attack. This attack causes the server to get overburdened within a short span of time. The zombie computers are controlled by hackers by means of malware. Because of the large number of computers involved in the attack, the power of the attacker gets magnified thousands of times. The best way to protect against distributed denial of service attacks is to use a traffic filter. A traffic filter is a device that prevents traffic from the IPs from where the malicious requests are originating.
Again it is worth to mention what Symantec website says about this:
“A Distributed DoS (DDoS) is the combined effort of several machines to bring down victim. In many cases there is a master machine that launches the attack to zombie machines that are part of a bot network, as shown below in Figure 1. Some bot networks contain many thousands of machines used to launch an attack.”
-Mohd Anwar Jamal Faiz
Software Engineer (White Box API and Security) at Leading Software Product Company
DOS or Denial of Service attack: This is a common way to attack a computer network. The main intention of a DOS attack is to disrupt the activities of the server through overloading it with unwanted requests. The attacker usually sends large number of requests to the server which leads to overloading. When the server gets overloaded, it is unable to answer to normal requests. DOS attacks are usually directed at websites. It is very easy to prevent and stop DOS attacks. In very plain words it should be noted that DOS attack if properly done can bring server on knees. Users and some scripts and functions would be starved of some services. These services may be among some of the crucial ones.
As said on the Symantec Website:
“ DoS is a Denial of Service to a victim trying to access a resource. In many cases it can be safey said that the attack requires a protocol flaw as well as some kind of network amplification.
Denial of Services is also an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services through the the consumption of bandwidth of the victim network, or the overloading the computational resources of the victim system.
The motivation for DoS attacks is not to break into a system. Instead, it is to deny the legitimate use of the system or network to others who need its services. One can say that this will typically happen through one of the following means:
1. Crashing the system.
2. Deny communication between systems.
3. Bring the network or the system down or have it operate at a reduced speed which affects productivity.
4. Hang the system, which is more dangerous than crashing since there is no automatic reboot. Productivity can be disrupted indefinitely.”
There is yet another but more advanced form of denial of service attack. Here, a large number of zombie computers are used to send requests to the server which is being attacked. This is popularly known as DDOS or Distributed Denial of Service Attack. This attack causes the server to get overburdened within a short span of time. The zombie computers are controlled by hackers by means of malware. Because of the large number of computers involved in the attack, the power of the attacker gets magnified thousands of times. The best way to protect against distributed denial of service attacks is to use a traffic filter. A traffic filter is a device that prevents traffic from the IPs from where the malicious requests are originating.
Again it is worth to mention what Symantec website says about this:
“A Distributed DoS (DDoS) is the combined effort of several machines to bring down victim. In many cases there is a master machine that launches the attack to zombie machines that are part of a bot network, as shown below in Figure 1. Some bot networks contain many thousands of machines used to launch an attack.”
-Mohd Anwar Jamal Faiz
Software Engineer (White Box API and Security) at Leading Software Product Company
Thursday, July 29, 2010
Rich Internet Applications (RIAs) and Use of Adobe Flex in creating RIA
Rich Internet applications (RIAs) offer a rich, engaging experience that improves user satisfaction and increases productivity. Using the broad reach of the Internet, RIAs can be deployed across browsers and desktops. It enables a new class of applications that combines the responsiveness and interactivity of desktop applications with the broad reach and ease of distribution of the web. RIAs can yield increased return on investment (ROI) by providing simple means and improving the user interaction-enabling users to find information more easily, complete tasks quickly and accurately, and use rich data visualization to make better presentations as well as improved decisions.
Basically RIA is a technology that caters to following two need of the hour:
• A new class of client runtime that can support the range of needs inherent in rich Internet business applications
• Tools and technology that can provide a productive environment for building, maintaining, and managing these applications throughout their lifecycle
As mentioned by Adobe Official Website, RIAs offer organizations a proven, cost-effective way to deliver modern applications with real business benefits:
• Offer users a richer, more engaging experience.
• Keep pace with users' rising expectations.
• Increase customer loyalty and generate higher profits.
• Leverage existing personnel, processes, and infrastructure.
It is very important to note that business executives increasingly recognize the value customer engagement brings to their businesses. For example, in a recent study on engagement conducted by the Economist Intelligence Unit on behalf of Adobe, 80% of executives said that better engagement translates into improved customer loyalty, and 75% said they believed it meant higher profits. In March 2007, Forrester Research published "The Business Case for Rich Internet Applications," a report based on interviews with RIA technology providers and designers, as well as Forrester Research clients and customers. The report revealed that "well-designed RIAs can produce eye-popping results that can help prove the value of current investments and make the case for future RIA projects."
The first point before adopting RIA is to identify which technology is best. Undoubtedly, a unanimous choice would be Adobe products and framework. This becomes so easy choice because of primarily two reasons:
1) Usefullness and effectiveness
2) Less effort to adopt and build applications
3) Beautiful animation and visual appeal
4) Prominence of Flash Run Time Environment over computers worldwide.
If I try to analyze the fourth point in a better way, I would conclude that building RIAs with Adobe technologies offers additional benefits. Adobe's clients have a long history of delivering consistent, cross-platform experiences. The Adobe® Flash® Player runtime reaches 98% of Internet-enabled desktops and more than 450 million devices, offering businesses greater reach than with any other client technology available. Adobe AIR™, the latest client from Adobe, leverages the power of Flash Player while adding the capability to deploy RIAs directly to the desktop.
Finally, since Adobe technologies enable designers and developers to build RIAs with their current tools and skills, businesses can leverage existing personnel and assets to enhance customer engagement while minimizing expense.
Flex is a standard-based programming model for high performance rich internet applications. Flex application will take advantage of adobe flash player 9, 10 et. Al. and this will enable developer to extend the capabilities enables the client with richer applications in real time. Technically, the Flex framework represents the presentation tire in multitier architecture applications and will be easy integrated with server-side functionality. If you want to create flex application then, you will start this application on Flex builder, which is IDE with visual layout, debugging, skinning, coder hinting and styling for developing rich Internet applications. In my opinion, the biggest advantages of using the Flash player as a runtime for your RIA as opposed to using AJAX: Firstly, the Write once, deploy cross platform capability. Secondly, You can turn your Flex application into a desktop application without much changes. So that means switching your application from Web based to Desktop and Vice versa is so easy in Flex. Thirdly, you can build UI's that look and feel the way you want them to, and not forced into having limitations by your development technology. Fourth, Flex provides many many tools, data grids, containers, components, 3d integration etc. Fifth ActioScript 3.0 provides you endless features and capabilities. And lastly, you can run Flex based Flash swf files even with PHP, Java or Asp.net. And in addition, there are many other benefits that compel anyone to learn, try and use Flex.
So wish you all great applications to come up from Adobe flex. Rich Internet Applications have started blooming and I can only see them in coming future. A long time to reign for RIAs particularly Adobe Flex and AS 3.0. (IMO (, in my opinion) ;) )
Happy Flexing!!!
Mohd Anwar Jamal Faiz
View ToughJamy : An Informal Me!!
View MeOnShow Website
Basically RIA is a technology that caters to following two need of the hour:
• A new class of client runtime that can support the range of needs inherent in rich Internet business applications
• Tools and technology that can provide a productive environment for building, maintaining, and managing these applications throughout their lifecycle
As mentioned by Adobe Official Website, RIAs offer organizations a proven, cost-effective way to deliver modern applications with real business benefits:
• Offer users a richer, more engaging experience.
• Keep pace with users' rising expectations.
• Increase customer loyalty and generate higher profits.
• Leverage existing personnel, processes, and infrastructure.
It is very important to note that business executives increasingly recognize the value customer engagement brings to their businesses. For example, in a recent study on engagement conducted by the Economist Intelligence Unit on behalf of Adobe, 80% of executives said that better engagement translates into improved customer loyalty, and 75% said they believed it meant higher profits. In March 2007, Forrester Research published "The Business Case for Rich Internet Applications," a report based on interviews with RIA technology providers and designers, as well as Forrester Research clients and customers. The report revealed that "well-designed RIAs can produce eye-popping results that can help prove the value of current investments and make the case for future RIA projects."
The first point before adopting RIA is to identify which technology is best. Undoubtedly, a unanimous choice would be Adobe products and framework. This becomes so easy choice because of primarily two reasons:
1) Usefullness and effectiveness
2) Less effort to adopt and build applications
3) Beautiful animation and visual appeal
4) Prominence of Flash Run Time Environment over computers worldwide.
If I try to analyze the fourth point in a better way, I would conclude that building RIAs with Adobe technologies offers additional benefits. Adobe's clients have a long history of delivering consistent, cross-platform experiences. The Adobe® Flash® Player runtime reaches 98% of Internet-enabled desktops and more than 450 million devices, offering businesses greater reach than with any other client technology available. Adobe AIR™, the latest client from Adobe, leverages the power of Flash Player while adding the capability to deploy RIAs directly to the desktop.
Finally, since Adobe technologies enable designers and developers to build RIAs with their current tools and skills, businesses can leverage existing personnel and assets to enhance customer engagement while minimizing expense.
Flex is a standard-based programming model for high performance rich internet applications. Flex application will take advantage of adobe flash player 9, 10 et. Al. and this will enable developer to extend the capabilities enables the client with richer applications in real time. Technically, the Flex framework represents the presentation tire in multitier architecture applications and will be easy integrated with server-side functionality. If you want to create flex application then, you will start this application on Flex builder, which is IDE with visual layout, debugging, skinning, coder hinting and styling for developing rich Internet applications. In my opinion, the biggest advantages of using the Flash player as a runtime for your RIA as opposed to using AJAX: Firstly, the Write once, deploy cross platform capability. Secondly, You can turn your Flex application into a desktop application without much changes. So that means switching your application from Web based to Desktop and Vice versa is so easy in Flex. Thirdly, you can build UI's that look and feel the way you want them to, and not forced into having limitations by your development technology. Fourth, Flex provides many many tools, data grids, containers, components, 3d integration etc. Fifth ActioScript 3.0 provides you endless features and capabilities. And lastly, you can run Flex based Flash swf files even with PHP, Java or Asp.net. And in addition, there are many other benefits that compel anyone to learn, try and use Flex.
So wish you all great applications to come up from Adobe flex. Rich Internet Applications have started blooming and I can only see them in coming future. A long time to reign for RIAs particularly Adobe Flex and AS 3.0. (IMO (, in my opinion) ;) )
Happy Flexing!!!
Mohd Anwar Jamal Faiz
View ToughJamy : An Informal Me!!
View MeOnShow Website
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