interpreter

A program that executes instructions written in a high-level language. There are two ways to run programs written in a high-level language. The most common is to compile the program; the other method is to pass the program through an interpreter.

An interpreter translates high-level instructions into an intermediate form, which it then executes. In contrast, a compiler translates high-level instructions directly into machine language. Compiled programs generally run faster than interpreted programs. The advantage of an interpreter, however, is that it does not need to go through the compilation stage during which machine instructions are generated. This process can be time-consuming if the program is long. The interpreter, on the other hand, can immediately execute high-level programs. For this reason, interpreters are sometimes used during the development of a program, when a programmer wants to add small sections at a time and test them quickly. In addition, interpreters are often used in education because they allow students to program interactively.

Both interpreters and compilers are available for most high-level languages. However, BASIC and LISP are especially designed to be executed by an interpreter. In addition, page description languages, such asPostScript, use an interpreter. Every PostScript printer, for example, has a built-in interpreter that executes PostScript instructions.

Read More

compile

)To transform a program written in a high-level programming language from source code into object code.Programmers write programs in a form called source code. Source code must go through several steps before it becomes an executable program. The first step is to pass the source code through a compiler, which translates the high-level language instructions into object code.

The final step in producing an executable program -- after the compiler has produced object code -- is to pass the object code through a linker. The linker combines modules and gives real values to all symbolic addresses, thereby producing machine code.

Read More

Compiler

)A program that translates source code into object code. The compiler derives its name from the way it works, looking at the entire piece of source code and collecting and reorganizing the instructions. Thus, a compiler differs from an interpreter, which analyzes and executes each line of source code in succession, without looking at the entire program. The advantage of interpreters is that they can execute a program immediately. Compilers require some time before an executable program emerges. However, programs produced by compilers runmuch faster than the same programs executed by an interpreter.

Every high-level programming language (except strictly interpretive languages) comes with a compiler. In effect, the compiler is the language, because it defines which instructions are acceptable.

Because compilers translate source code into object code, which is unique for each type of computer, many compilers are available for the same language. For example, there is a FORTRAN compiler for PCs and another for Apple Macintosh computers. In addition, the compiler industry is quite competitive, so there are actually many compilers for each language on each type of computer. More than a dozen companies develop and sellCcompilers for the P

Read More

machine language

Machine language is the lowest-level programming language(except for computers that utilize programmable microcode). Machine languages are the only languages understood bycomputers.

Why Humans Don't Use Machine Language

While easily understood by computers, machine languages are almost impossible for humans to use because they consist entirely of numbers. Programmers, therefore, use either a high-level programming language or an assembly language. An assembly language contains the same instructions as a machine language, but the instructions and variables have namesinstead of being just numbers.

Programs written in high-level languages are translated into assembly language or machine language by acompiler. Assembly language programs are translated into machine language by a program called anassembler.

Every CPU has its own unique machine language. Programs must be rewritten or recompiled, therefore, to runon different types of computers.

Read More

command

An instruction to a computer or device to perform a specific task.Commands come in different forms. They can be:

special words (keywords) that a program understands.

• function keys

choices in a menu

• buttons or other graphical objects on your screen

Every program that interacts with people responds to a specific set of commands. The set of commands and the syntax for entering them is called the user interface and varies from one program to another.

The DOS operating system makes a distinction between internaland external commands. Internal commands are commands, such as COPY and DIR, that can be handled by the COMMAND.COM program. External commands include thenames of all other COM files, as well as EXE and BAT files.

Read More

program

There are many programming languages -- C, C++, Pascal, BASIC,FORTRAN, COBOL, and LISP are just a few. These are all high-level languages. One can also write programs in low-level languages called assembly languages, although this is more difficult. Low-level languages are closer to the languageused by a computer, while high-level languages are closer to human languages.
A program is like a recipe. It contains a list of ingredients (calledvariables) and a list of directions (called statements) that tell the computer what to do with the variables. The variables can represent numeric data, text, or graphical images.(n) An organized list of instructions that, when executed, causes thecomputerto behave in a predetermined manner. Without programs, computers are useless.

Eventually, every program must be translated into a machine language that the computer can understand. This translation is performed by compilers, interpreters, and assemblers.

When you buy software, you normally buy an executable version of a program. This means that the program is already in machine language -- it has already been compiledand assembled and is ready to execute.

(v) To write programs.

Read More

instruction

A basic command. The term instruction is often used to describe the most rudimentary programming commands. For example, acomputer's instruction set is the list of all the basic commands in the computer's machine language.

Read More

Software

Software means computer instructions or data. Anything that can be stored electronically is software, in contrast to storage devicesand display devices which are called hardware.

The Difference Between Software and Hardware

The terms software and hardware are used as both nouns and adjectives. For example, you can say: "The problem lies in the software," meaning that there is a problem with the program or data, not with the computer itself. You can also say: "It is a software problem."

The distinction between software and hardware is sometimes confusing because they are so integrally linked. Clearly, when you purchase a program, you are buying software. But to buy the software, you need to buy the disk (hardware) on which the software is recorded.

Categories of Computer Software

Software is often divided into two categories.  Systems software includes the operating system and all the utilitiesthat enable the computer to function. Applications software includes programs that do real work for users. For example, word processors, spreadsheets, and database management systems fall under the category of applications software.

Top 5 Software Related Questions

1. What is application software?

2. What is systems software?

3. What is software package?

4. What is software engineer?

       5.What is enterprise application?

Read More

HOW TO HACK AOL®, YAHOO® AND HOTMAIL®

We get numerous calls from people who want to recover AOL®, Yahoo® or Hotmail® or other online and email passwords. We do not do this type of work. Many of these people claim that they have lost their passwords because they have been hacked and now need to get their password back. As we have reviewed information on the web, we found very little real information about the actual techniques that could be used to hack these services. So we decided to pull together a detailed explanation.   What follows is a detailed explanation of the methodologies involved. We do not condone any illegal activity and we clearly mention in this article techniques that are illegal. Sometimes these methods are known as "Phishing."   You can also search for additional information at the IT Security Search Engine, Security Search Authority.   THE HOAX Let's dispose of one technique that is absolutely a hoax (meaning a fraud: something intended to deceive; deliberate trickery intended to gain an advantage.) If you see a newsgroup post or web page with something like the following, it is a hoax and will not work.   : : : (([[THIS REALLY WORKS ]])) : : : (1) send an E-mail to passwordrecovery@yourdomainhere.com (2) In the subject box type the screenname of the person whose password you wish to steal (3) In the message box type the following: /cgi-bin/start?v703&login.USER=passmachine&class=supervisor&f={your aol password}&f=27586&javascript=ACTIVE&rsa (4) Send the e-mail with priority set to "high" (red ! in some mailprograms) (5) wait 2-3 minutes and check your mail (6) Read the message.-Where YOUR password was typed before, NOW, the password of the screenname in the code string is there!!! Why does this work? It´s a special decryption-server that AOL-employees can use to decrypt passwords.The aolbackdoor account is a bot that reads your authentification from the message body and identifiying you as a valid AOL Staff-member, you will get the password mailed back to you. The trick is that this Bot´s script seems to be a little bit buggy and it automatically recogises you as an supervisor (AOL-Staff member), even if you use a normal AOL account. This means, that EVERYONE having a valid AOL account can hack as many other accounts as he wants.   This is just a scam to steal your password and may explain some of the calls we get from people saying they were hacked. Never give your password to anyone. No legitimate web service or customer service representative will ask for it or need it. There is no magic email address or series of commands that will reveal the passwords of users.   LOCALLY STORED PASSWORDS Most browsers, including Internet Explorer® and Netscape®, the AOL® client, and Windows® Dial-Up Connections allow you the option to store passwords. These passwords are stored on the local machine and (depending upon where and how it is stored) there is usually a method of recovering these passwords. Storing any password locally is insecure and may allow the password to be recovered by anyone who has access to the local machine. While we are not currently aware of any program to recover locally stored AOL® passwords, we do not recommend that these are secure. Software does exist that can recover most of the other types of locally stored passwords.   TROJAN A Trojan is a program that is sent to a user that allows an attacker to control functions of the target computer, recover information from the target or to delete or damage files on the target. The name Trojan is given because the program will usually come attached to some other program or file that entices you to run it. There are a wide variety of Trojans any number of which can be programmed to capture passwords as they are typed and to email or transmit them to a third party. To protect yourself against Trojans, you should never execute or download software or files that are not from a trusted source. It is critical that anyone working on internet use a virus protection program (which should catch most Trojans.) Note that since a Trojan requires the password to be typed or stored in order to be recovered, this is not an effective way to recover your own password. It could explain, however, how someone could lose their password to a hacker. Sending someone a Trojan program is certainly illegal and we do not recommend or condone this activity. A Trojan is unlikely to be effective in recovering a particular account password since it requires the target to install it. However, hackers will often bulk mail Trojans to thousands of people in the hope that a small percentage will get caught. Legitimate account holders who may have been caught by a Trojan and can authenticate themselves should contact their service provider to have their account passwords reset.   KEYLOGGER A keylogger is a program or piece of hardware that records all keyboard keystrokes to an encrypted file which can then be read later. Based on the order of the keystrokes, it is usually easy to identify the password(s) from the file later. Like the Trojan, this also requires that someone actually type the password. Keyloggers come in two types: hardware and software. A hardware keylogger can be fitted between the keyboard cable and the computer and can be activated with a few keystrokes. It is then left in place until after the password that you are looking to recover is typed. Later it is removed and the file of keystrokes is examined for the password. A hardware keylogger is undectable by anti-virus software. A software keylogger is installed on a system and effectively has the same function, however, it is a little bit more complex to use since it must be installed to run stealthily to be effective. A keylogger could be used to steal a password from someone who is using an office computer or sharing a computer. It is possible that installing and using such a device or piece of software could be illegal depending upon whether the target has a presumption of privacy when using the computer on which the keylogger is installed.   IMPERSONATION It is possible to impersonate a program on a computer by launching windows that look like something else. For instance, let's say you login to the MSN® service and visit a website (in this case a hostile website.) It would be possible for this website to pop-up some windows that look like something else. They could look almost identical to windows that an inexperienced user might expect from his local computer. The user could be fooled into submitting information to the hostile website. For instance, consider the effect of seeing the following series of windows:       If these could trick you into entering your password, then you could end-up sending your password to the attacker. Windows such as these could be created to mirror virtually any program or series of actions. Your browser will likely identify your operating system and your IP address might identify your ISP. Therefore, a hostile website could target you with a series of screen shots that look exactly as they should on your system. The key is that the screen shots are not coming from your system, but are coming from the hostile website. First, creating such a hostile website is probably fraudulent and illegal. We do not recommend or condone this activity. To protect yourself against this type of attack, make sure to configure your browser for high security and enable warnings for any code that is executed on your system.   SNIFFING If two people do not share the same computer, but do share the same network, it may be possible for one to sniff the others' packets as they sign-on. The traffic between your computer and the internet site you are accessing may be able to be recorded and decrypted or "played-back." This is not a simple attack to execute, but is possible if two people are close to one another and share a hub. Again, this is likely to be illegal and we do not condone this activity.   BRUTE-FORCE ATTACK Many people want to find software to perform a brute-force attack. This is really impractical. It would take hundreds of thousands of years to attempt any kind of reasonable brute-force attack on AOL®, Yahoo® or Hotmail® and this would expand exponentially if the password is longer than the minimum length. Using multiple computers or multiple sessions could reduce this to merely thousands of years. This is highly illegal since these services own the servers on which an account is hosted. Even if you are hacking your own account, you don't own the servers and the service is going to monitor and log this activity. It is extremely unlikely that you could recover a password in this way, but it is extremely likely that you'd be arrested and prosecuted for doing this.   SOCIAL ENGINEERING Social engineering is the name given to the art of attacking the person, rather than the computer or system. The basic principle is that many people can be talked into giving someone else their id and password if they think it is someone that they can trust. For instance, I might call someone and say I was from AOL and that I was finally getting around to responding to their technical support question. I would then ask you to describe the problem that you are having and tell you that we have a solution. However, I just need to verify the account. Can you give me the username and password again? A surprising number of people would fall for this obvious scam. There is no limit as to how elaborate this can be. The more information that is given by the caller, the more realistic or believable the call is. Again, never give your password to anyone. No legitimate customer service representative will ask for this information.   These are the basic methods that we are aware of for hacking an AOL®, Yahoo®, Hotmail® or any other dial-up or on-line password. Hopefully this will answer some questions and help you protect yourself against these attacks.   Password Crackers, Inc. does offer an America Online (AOL)® Personal Filing Cabinet (.pfc) conversion service. We can convert AOL® Personal Filing Cabinets (.pfc) to either Netscape®, Microsoft Outlook® (.pst) or text (.txt) formats. You can get more information about this service here.

Read More

Password Crackers,

Password Crackers, Inc. offers services and software to convert your America Online (AOL)® Personal Filing Cabinet (.pfc) files and items to Microsoft Outlook® (.pst) format, Netscape® format, or Text (.txt) format.

America Online (AOL)® offers users the option to store incoming/read and sent email items in the AOL® Personal Filing Cabinet (.pfc). AOL® can store these items in the Personal Filing Cabinet on the user’s local hard disk automatically if the user chooses this option. These items can then be reviewed by opening the Personal Filing Cabinet in AOL®. The Personal Filing Cabinet (.pfc) is stored on the local hard disk in a proprietary AOL® format. In addition to email items, the Personal Filing Cabinet can store newsgroup messages, downloaded files, favorite places and the user’s address book (as well as some other items.) The Personal Filing Cabinet is usually stored on the users hard disk in the AOL® directory in a subdirectory called \organize. It will have the same name as the users’ AOL® screen name and no extension.

Password Crackers, Inc. offers a conversion service to convert data in the AOL® proprietary Personal Filing Cabinet (.pfc) format to either text format (.txt), Netscape® format, or Microsoft Outlook® format (.pst) so that users can access these email items without using AOL®. All Personal Filing Cabinet (.pfc) email items can be converted to either .pst or .txt formats. Newsgroup postings (if any) can only be converted to .txt or Netscape® format, since Microsoft Outlook® does not store newsgroup postings. We do not convert the list of downloaded files. Addressbooks are converted to Outlook (.pst) format and Favorite Places are returned as a favorites.htm file which can be imported directly into Internet Explorer or other browsers. At this time the service is only available to users on PC compatible platforms. We do not currently offer the service for users on Mac platforms. We can convert mail items from all PC versions of AOL®.

Password Crackers, Inc.'s AOL® Personal Filing Cabinet (.pfc) conversion service is $75/PFC for files returned in Outlook® .pst format. This includes conversion of AOL® stored email, Addressbook and Favorites. For files returned in other formats, files that contain newsgroup items, or bulk file conversions, please contact us first by email for a written quote.

Read More