155 Sentences With "executable code" | Random Sentence Generator

Malware could contain executable code to turn on your webcam.

The tool allows researchers to upload firmware images, which the tool examines by extracting executable code where malware might be present.

Earth technology roadmap (and this is a common aspect of ICO white papers) the goal sounded more aspirational than grounded in executable code.

Think of the service mesh as the toolkit that keeps microservices communicating with each other and enabling applications at the level of executable code.

To this end, he developed what is arguably the smallest possible executable code (code that can be read by a machine) that can be represented by a prime number.

If you accidentally click a bad link or download the wrong file, that malware could contain executable code to turn on your webcam and send that video feed to a website or save it somewhere else.

One can reference an executable code library by using the /reference flag of the C# compiler.

A package that has a standardized structure for storing executable code and its associated resources, is called a bundle.

2, 5.5.3 - All published for IBM-PC. v3.1C was the first compiled into direct executable code. 4.0 was the first to feature networking.

Kotlin can also be used as a scripting language. A script is a Kotlin source file (.kts) with top level executable code. // list_folders.

They also attempted but failed to exploit CPU operations for memory alignment, division by zero, supervisor modes, segment limits, invalid opcodes, and non-executable code.

System Engineering is supported with SysML 1.4 modeling which can be coupled with executable code generation. SysML supports modeling from requirement definition and system composition using SysML Blocks and Parts, through to parametric model simulation. The executable code generation supports embedded HDL system languages (Ada, VHDL and Verilog), or it can be coupled with behavioral code generation of the standard code languages defined above.

Visual Studio features background compilation (also called incremental compilation). As code is being written, Visual Studio compiles it in the background in order to provide feedback about syntax and compilation errors, which are flagged with a red wavy underline. Warnings are marked with a green underline. Background compilation does not generate executable code, since it requires a different compiler than the one used to generate executable code.

WinAlign (Walign.exe and Winalign.exe) are tools designed to optimize the performance of executable code (binaries). WinAlign aligns binary sections along 4 KB boundaries, aligning the executable sections with the memory pages.

CIP-Tool permits models to be automatically converted to executable code. This greatly facilitates testing, documentation and final implementation. Currently the languages C/C++ and Java are supported as output formats.

Examples include natural language programming,Little, Greg, and Robert C. Miller. "Translating keyword commands into executable code." Proceedings of the 19th annual ACM symposium on User interface software and technology. ACM, 2006.

The Arduino IDE employs the program avrdude to convert the executable code into a text file in hexadecimal encoding that is loaded into the Arduino board by a loader program in the board's firmware.

Just in time compilation (JIT) is the generation of executable code on-the-fly or as close as possible to its actual execution, to take advantage of run time metrics or other performance enhancing options.

Single-use participants are restricted to use RELAP5-3D on a single computer, one user at a time. They receive the RELAP5-3D executable code and may receive up to 5 hours of staff assistance.

This allows the programmer to change executable code while it is running, set break points, and use other advanced debugging techniques on an embedded system, where such operations would not be possible otherwise. This type of tool appeared in 1980s-1990s, when most embedded systems were using discrete ROM (or later flash memory) chip, containing executable code. This allowed for easy replacing of ROM/flash chip with emulator. Together with excellent productivity of this tool this had driven an almost universal use of it among embedded developers.

Class designers allow the specification of arbitrarily complex data structures in a convenient form and the prescriptive nature of this description allows generation of executable code to perform list management, format translation, endian swapping and so on.

In NeXTSTEP, OPENSTEP, GNUstep, and their lineal descendants macOS and iOS, a bundle is a file directory with a defined structure and file extension, allowing related files to be grouped together as a conceptually single item. Examples of bundles that contain executable code include applications, frameworks, and plugins. This kind of bundle usually contains one file representing executable code, and files that represent resources such as nibs, templates, images, sounds, and other media. On some other systems, such as Microsoft Windows, these resources are usually included directly in the executable file itself at compile time.

Implementing literate programming consists of two steps: # Weaving: Generating a comprehensive document about the program and its maintenance. # Tangling: Generating machine executable code Weaving and tangling are done on the same source so that they are consistent with each other.

Self-extracting archives will only run under the operating system with which they are compatible. Also, since they must include executable code to handle the extraction of the contained archive file, they are a little larger than the original archive.

Some systems combine the offline and online approaches. Some systems write out executable code (e.g., JSP, ASP, PHP, ColdFusion, or Perl pages) rather than just static HTML. That way, personnel don't have to deploy the WCMS itself on every web server.

A specification language is a formal language in computer science used during systems analysis, requirements analysis, and systems design to describe a system at a much higher level than a programming language, which is used to produce the executable code for a system.

Timing attacks are often overlooked in the design phase because they are so dependent on the implementation and can be introduced inadvertently with compiler optimizations. Avoidance of timing attacks involves design of constant-time functions and careful testing of the final executable code.

The compiler can be operated from, and generate executable code for, the DOS, OS/2, Windows, Linux operating systems. It also supports NLM targets for Novell NetWare. There is ongoing work to extend the targeting to LinuxInstalling Open Watcom on Linux - Open Watcom. OpenWatcom.org wiki.

Dynamic statements specify processing operations and result in executable code generation by the compiler. A dynamic statement consists of an operator followed by a list of operands and additional operators. An operand may be a single name, a constant, a data-element reference or an expression.

On an IBM PC compatible machine, the BIOS selects a boot device, then copies the first sector from the device (which may be a MBR, VBR or any executable code), into physical memory at memory address 0x7C00. On other systems, the process may be quite different.

Graphical Plots of the simulation can be generated. There is also support for generating executable code from State Machines for both simulation, as well for use in applications. BPMN models (using BPSim), can be simulated creating tabulated results for analysis. BPSim also supports Monte Carlo probability-based simulations.

A typical parser generator associates executable code with each of the rules of the grammar that should be executed when these rules are applied by the parser. These pieces of code are sometimes referred to as semantic action routines since they define the semantics of the syntactic structure that is analyzed by the parser. Depending upon the type of parser that should be generated, these routines may construct a parse tree (or abstract syntax tree), or generate executable code directly. One of the earliest (1964), surprisingly powerful, versions of compiler-compilers is META II, which accepted an analytical grammar with output facilities that produce stack machine code, and is able to compile its own source code and other languages.

Many imperative languages (e.g. C) make a distinction between statements and definitions, with a statement only containing executable code and a definition instantiating an identifier, while an expression evaluates to a value only. A distinction can also be made between simple and compound statements; the latter may contain statements as components.

Fifteen proposals were received, based on a variety of technical approaches, including obscured source code, compiler intermediate languages, and annotated executable code. The technology of ANDF, chosen after an evaluation of competing approaches and implementations, was Ten15 Distribution Format, later renamed TenDRA Distribution Format, developed by the UK Defence Research Agency.

Unlike the RUP, the AUP has only seven disciplines : # Model. Understand the business of the organization, the problem domain being addressed by the project, and identify a viable solution to address the problem domain. # Implementation. Transform model(s) into executable code and perform a basic level of testing, in particular unit testing.

In a language with free pointers or non-checked array writes (such as in C), the mixing of control flow data which affects the execution of code (the return addresses or the saved frame pointers) and simple program data (parameters or return values) in a call stack is a security risk, possibly exploitable through stack buffer overflows as the most common type of buffer overflows. One of such attacks involves filling one buffer with arbitrary executable code, and then overflowing the same or some other buffer to overwrite some return address with a value that points directly to the executable code. As a result, when the function returns, the computer executes that code. This kind of an attack can be easily blocked with W^X.

Scrap (.shs) files have been used by viruses because they can contain a wide variety of files (including executable code), and the file extension is not shown even when "Hide file extensions from known file types" is disabled. The functionality can be restored by copying registry entries and the DLL from a Windows XP system.

Every application contains al least a Code #0 resource with size information and jump tables, a Code #1 resource with executable code and data resources containing pre-initialized values of global variables in compressed form. Other resources that may be contained are forms, form objects, alerts and multimedia data, e. g. images and sounds.

File systems with folders are typically absent as are SQL databases. Software development requires use of a cross compiler, which runs on a computer but produces executable code for the target device. Debugging requires use of an in-circuit emulator, JTAG or SWD. Software developers often have access to the complete kernel (OS) source code.

These are arbitrary bit patterns that specify, when control is passed to the subprogram, which registers are to be preserved. Since register masks are a form of data embedded within the executable code, they can make linear parsing of the machine code difficult. This can complicate optimization techniques that are applied on machine code.

Application bundles are directory hierarchies, with the top-level directory having a name that ends with a `.app` extension. In an application bundle, the first directory in the bundle underneath the top-level directory is usually named `Contents`. Within `Contents` there is usually another directory (called `MacOS` on Macs), which contains the application's executable code.

Object files -- executable or not -- are typically stored in a container format, such as Executable and Linkable Format (ELF) or Portable Executable (PE) which is Operating System-specific. This gives structure to the generated machine code, for example dividing it into sections such as .text (executable code), .data (initialized global and static variables), and .

WindowsSCOPE shows processes, DLLs, and drivers running the computer at the time of the memory snapshot as well as open network sockets, file handles, and registry key handles. It also provides disassembly and control flow graphing for executable code. WindowsSCOPE Live is a version of the tool that allows analysis to be performed from a mobile device.

Existing 8080 assembly source code (albeit no executable code) was thereby made upward compatible with the new 8086 to a degree. In contrast, the 432 had no software compatibility or migration requirements. The architects had total freedom to do a novel design from scratch, using whatever techniques they guessed would be best for large- scale systems and software.

JAL (Just Another Language) is a Pascal-like programming language and compiler that generates executable code for PIC microcontrollers. It is a free-format language with a compiler that runs on Linux, MS-Windows and MS-DOS (OSX support). It is configurable and extendable through the use of libraries and can even be combined with PIC assembly language.

The S-record format was created in the mid-1970s for the Motorola 6800 processor. Software development tools for that and other embedded processors would make executable code and data in the S-record format. PROM programmers would then read the S-record format and "burn" the data into the PROMs or EPROMs used in the embedded system.

Position-independent executables (PIE) are executable binaries made entirely from position-independent code. While some systems only run PIC executables, there are other reasons they are used. PIE binaries are used in some security-focused Linux distributions to allow PaX or Exec Shield to use address space layout randomization to prevent attackers from knowing where existing executable code is during a security attack using exploits that rely on knowing the offset of the executable code in the binary, such as return-to-libc attacks. Apple's macOS and iOS fully support PIE executables as of versions 10.7 and 4.3, respectively; a warning is issued when non-PIE iOS executables are submitted for approval to Apple's App Store but there's no hard requirement yet and non-PIE applications are not rejected.

This allows programs to load and save any files for which the corresponding datatypes exist. File descriptors did not need to be embedded in the executable code. An independent system of loaders was not needed for new productivity software. Amiga productivity software tools therefore have a smaller size and a more clean design than similar programs running in other operating systems.

The tool could also generate from them, automatically, executable code; first in the Ada programming language and later also in the C programming language.STATEMATE: a working environment for the development of complex reactive systems, In 1987, the company was re-formed as a USA entity, called I-Logix Inc., and AdCad Ltd. became its R&D; branch, renamed as I-Logix Israel, Ltd.

The Executable UML method enables valuing the model as intellectual property, since the model is a fully executable solution for the problem space. Actions are specified in action language. This means that the automatic generation of implementation code from Executable UML models can be output in an optimized form. Executable UML is intended to serve as executable code as well as documentation.

A computer virus is software usually hidden within another seemingly innocuous program that can produce copies of itself and insert them into other programs or files, and that usually performs a harmful action (such as destroying data). An example of this is a PE infection, a technique, usually used to spread malware, that inserts extra data or executable code into PE files.

DTM placement and deployment density is driven by the targeted needs of the respective utility. Remote Over-The-Air (OTA) updates / upgrades are supported by certain DTM device offerings. This OTA capability, when supported, allows the operator to perform remote configuration and / or executable code (i.e., Firmware) updates of the DTM device(s) without the need for costly truck rolls or unit replacement.

The only version of Lotus 1-2-3 offered for the Tandy 2000 was Release 1A. This was customized to take advantage of the unique hardware of the computer, including its full 768K of RAM, high resolution color graphics, and two extra function keys. Release 1A's executable code was about 60 KB smaller than the later Release 2, which provided greater macro programming facilities.

SYS is also a command in Microsoft BASIC used to execute a machine language program in memory. The command took the form `SYS n` where n is a memory location where the executable code starts. Home computer platforms typically publicised dozens of entry points to built-in routines (such as Commodore's KERNAL) that were used by programmers and users to access functionality not easily accessible through BASIC.

Scala ( ) is a general-purpose programming language providing support for both object-oriented programming and functional programming. The language has a strong static type system. Designed to be concise, many of Scala's design decisions are aimed to address criticisms of Java. Scala source code is intended to be compiled to Java bytecode, so that the resulting executable code runs on a Java virtual machine.

Radare2 (also known as r2) is a complete framework for reverse-engineering and analyzing binaries; composed of a set of small utilities that can be used together or independently from the command line. Built around a disassembler for computer software which generates assembly language source code from machine-executable code, it supports a variety of executable formats for different processor architectures and operating systems.

The program was named Turochamp, a combination of their surnames. It is sometimes misreported as "Turbochamp". According to Champernowne, his wife played a simulated game against the program, nicknamed the "paper machine", and lost. Turing attempted to convert the program into executable code for the 1951 Ferranti Mark 1 computer in Manchester, but was unable to do so due to the complexity of the code.

Source embeddable languages embed small pieces of executable code inside a piece of free-form text, often a web page. Client-side embedded languages are limited by the abilities of the browser or intended client. They aim to provide dynamism to web pages without the need to recontact the server. Server-side embedded languages are much more flexible, since almost any language can be built into a server.

Due to its ability to create or change executable code, OGNL is capable of introducing critical security flaws to any framework that uses it. Multiple Apache Struts 2 versions have been vulnerable to OGNL security flaws. As of October 2017, the recommended version of Struts 2 is 2.5.13. Users are urged to upgrade to the latest version, as older revisions have documented security vulnerabilities — for example, Struts 2 versions 2.3.

Max then tells Leo that he has found something in Anita's code: they discover David Elster had left executable code within Mia's programming. They find Doctor Millican, who helps them extract it. Leo connects himself with his laptop and tries to run the program. Niska finds a "Smash club" where synths are savagely beaten for entertainment and starts attacking the humans there with a baseball bat; she is cornered by police.

The `od` program can display output in a variety of formats, including octal, hexadecimal, decimal, and ASCII. It is useful for visualizing data that is not in a human-readable format, like the executable code of a program, or where the primary form is ambiguous (e.g. some Latin, Greek and Cyrillic characters looking similar). `od` is one of the earliest Unix programs, having appeared in version 1 AT&T; Unix.

While convenient, and required by many prepackaged scripts, it opens the server to attack if a remote user can upload executable code with the proper extension. In the case of HTTP PUT or POSTs, the user-submitted data are provided to the program via the standard input. The Web server creates a subset of the environment variables passed to it and adds details pertinent to the HTTP environment.

As a directory service, an Active Directory instance consists of a database and corresponding executable code responsible for servicing requests and maintaining the database. The executable part, known as Directory System Agent, is a collection of Windows services and processes that run on Windows 2000 and later. Objects in Active Directory databases can be accessed via LDAP, ADSI (a component object model interface), messaging API and Security Accounts Manager services.

Massalin's first breakthrough product came while studying at Columbia. Massalin developed Synthesis, an operating system kernel that allocated resources, ran security and low-level hardware interfaces, and created executable code to improve performance. Synthesis optimized critical operating system code using run-time information, which was a new insight previous thought impractical. To support Synthesis, Massalin invented object-like data structures called Quajects, which contain both data and code information.

The Interactive Disassembler (IDA) is a disassembler for computer software which generates assembly language source code from machine-executable code. It supports a variety of executable formats for different processors and operating systems. It also can be used as a debugger for Windows PE, Mac OS X Mach-O, and Linux ELF executables. A decompiler plug-in for programs compiled with a C/ compiler is available at extra cost.

It did so by purchasing one in order to decompile the executable code of three Genesis games. Such information was used to program their new Genesis cartridges in a way that would allow them to disable the security lockouts on the Genesis that prevented unlicensed games from being played., 977 F.2d 1510 (9th Cir. 1992) This strategy was used successfully to bring Ishido: The Way of Stones to the Genesis in 1990.

Compiled computer programs are commonly referred to as executables, binary images, or simply as binaries – a reference to the binary file format used to store the executable code. Some compiled and assembled object programs need to be combined as modules with a linker utility in order to produce an executable program. Interpreters are used to execute source code from a programming language line-by-line. The interpreter decodes each statement and performs its behavior.

The "predefined" method loads the program counter (PC) directly with the address of some entry inside the interrupt vector table. The jump table itself contains executable code. While in principle an extremely short interrupt handler could be stored entirely inside the interrupt vector table, in practice the code at each entry is a single jump instruction that jumps to the full interrupt service routine (ISR) for that interrupt. The Intel 8080, Atmel AVRRoger L. Traylor.

The Common Language Infrastructure (CLI) is an open specification (technical standard) developed by Microsoft and standardized by ISO and EcmaISO/IEC 23271:2012 - Information technology -- Common Language Infrastructure (CLI)Standard ECMA-335 - 6th edition (June 2012) that describes executable code and a runtime environment that allows multiple high-level languages to be used on different computer platforms without being rewritten for specific architectures. This implies it is platform agnostic. The .NET Framework, .

The Extended Memory Specification (XMS) is the specification describing the use of IBM PC extended memory in real mode for storing data (but not for running executable code in it). Memory is made available by extended memory manager (XMM) software such as HIMEM.SYS. The XMM functions are accessible through interrupt 2Fh. XMS version 2.0 allowed for up to 64 MB of memory, with XMS version 3.0 this increased to 4 GB (232 bytes).

On older Macintoshes, a similar technique is used, where additional metadata can be added to a file's resource fork. Similar in concept are the application directories used in RISC OS and on the ROX Desktop. Examples of bundles that do not contain executable code include document packages (iWork documents) and media libraries (iPhoto Library). Bundles are programmatically accessed with the `NSBundle` class in Cocoa, NeXTSTEP and GNUstep's Foundation frameworks, and with `CFBundle` in Core Foundation.

These resources are then placed in a directory along with the executable code and "raw data". The directory (called a "bundle" or "application directory") is then presented to the user as the application itself. This solution provides all of the same functionality as the resource fork, but allows the resources to be easily manipulated by any application – a "resource editor" (like ResEdit) is not needed. From the command line interface, the bundle appears to be a normal directory.

The first IBM PC to use the SMA was the IBM PCjr, released in 1984. Video memory was shared with the first 128KiB of RAM. The exact size of the video memory could be reconfigured by software to meet the needs of the current program. An early hybrid system was the Commodore Amiga which could run as a shared memory system, but would load executable code preferentially into non-shared "fast RAM" if it was available.

Once the decryption was done, the loader transferred control to the game program. The PC version was easy to circumvent, as the original game executable code was just stored inside the loader. Once you got past the disk checks, and encryption code, dumping the unencrypted executable was just a matter of performing 2 disk writes. The first would dump the unmodified "MZ" header, and the 2nd write would finish the job by saving the actual game code.

Under DR-DOS the file may be optionally password-protected as well. Under PC DOS, the system attribute is set in order to mark the file as non-movable, a restriction technically not necessary under DR-DOS. As IBMBIO.COM is a binary image containing executable code rather than a true COM-style program, the hidden attribute is set to keep the file from being accidentally invoked at the command prompt, which would lead to a crash.

A C-- dialect called Cmm is the intermediate representation for the Glasgow Haskell Compiler. GHC backends are responsible for further transforming C-- into executable code, via LLVM IR, slow C, or directly through the built-in native backend.GHC Backends Some of the developers of C--, including Simon Peyton Jones, João Dias, and Norman Ramsey, work or have worked on the Glasgow Haskell Compiler. Work on GHC has also led to extensions in the C-- language, forming the Cmm dialect.

Classes are "prototypes" for objects, like the idea of an apple is the prototype for the apple one can actually buy in a shop. It is known that an apple has a colour, and that it can be peeled: those are the data and executable "code" for the apple class. Oxygene provides language- level support for some features of parallel programming. The goal is to use all cores or processors of a computer to improve performance.

A workflow is a series of processing steps connected together so that the output of one step is used as the input of another. Processing steps implement data analysis tasks such as data importing, statistical tests and report generation. In Anduril, processing steps are implemented using components, which are reusable executable code that can be written in any programming language. Components are wired together into a workflow, or a component network, that is executed by the Anduril workflow engine.

Some Japanese users referred to this as an omamori (charm) left by Iwata himself. With the 4.0 update, the executable code for this Easter egg appears to have been wiped by Nintendo. In August 2018, a Twitter user found files on the Switch's firmware while reverse- engineering the console, which suggest that Nintendo was possibly testing VR functionality for the Switch. The Twitter user was able to activate the hidden "VR Mode", which split the screen into two displays.

MUCKs are extensible by design, players can create and modify ("build") all internal objects of the game environment, including rooms, exits, and even the system commands, for which the MUCKs use the MUF (Multi-User Forth) language. Fuzzball MUCKs also use Message Parsing Interpreter (MPI) which can be used to embed executable code into descriptions of all in-game objects. Unlike many other virtual worlds, however, TinyMUCK and its descendants do not usually have computer-controlled monsters for players to kill.

True text files are considered to be innocuous as they are incapable of running executable code. The worm used social engineering to entice users to open the attachment (out of actual desire to connect or simple curiosity) to ensure continued propagation. Systemic weaknesses in the design of Microsoft Outlook and Microsoft Windows were exploited that allowed malicious code capable of complete access to the operating system, secondary storage, and system and user data simply by unwitting users clicking on an icon.

Windows XP Service Pack 2 introduced Data Execution Prevention. This feature, present as NX (EVP) in AMD's AMD64 processors and as XD (EDB) in Intel's processors, can flag certain parts of memory as containing data instead of executable code, which prevents overflow errors from resulting in arbitrary code execution. It is intended to prevent an application or service from executing code from a non- executable memory region. This helps prevent certain exploits that store code via a buffer overflow, for example.

Originally, the term "build" referred to the process of compiling and linking source code into executable code. Typically, these executable codes would be stand-alone applications, such as Microsoft Word or Adobe Photoshop. During the 1990s, the typical release cycle for applications (such as the Microsoft Windows operating system) was 12 to 24 months. In traditional software development at that time, developers would typically check in code once a day, and would run a "nightly build" after all the code was checked in.

A non-executable stack can prevent some buffer overflow exploitation, however it cannot prevent a return-to-libc attack because in the return-to-libc attack only existing executable code is used. On the other hand, these attacks can only call preexisting functions. Stack-smashing protection can prevent or obstruct exploitation as it may detect the corruption of the stack and possibly flush out the compromised segment. "ASCII armoring" is a technique that can be used to obstruct this kind of attack.

In older versions of macOS, or if kext signing is disabled, a loadable kernel module in a kernel extension bundle can be loaded by non-root users if the OSBundleAllowUserLoad property is set to True in the bundle's property list. However, if any of the files in the bundle, including the executable code file, are not owned by root and group wheel, or are writable by the group or "other", the attempt to load the kernel loadable module will fail.

Words, lines, paragraphs, and pages could be slid from the lower window to the upper, as in the cassette tapes of the CPT 4200, or they could be deleted from the lower window. In addition the two screens could lock and scroll up or down together. The machine used two processors, an 8080 microprocessor and a custom display processor. 65,536 bytes of main memory were standard and were used jointly by both processors for executable code, program data, and video memory.

CTR is applicable to user-to-user traffic, such as email and chat, and machine-to-machine traffic, such as web services. Data transfers can be intercepted by in-line application layer proxies and these can transform the way information content is delivered to remove any threat. CTR works by extracting business information from data and it is not possible to extract information from executable code. This means CTR is not directly applicable to web browsing, since most web pages are code.

A stored procedure is executable code that is associated with, and generally stored in, the database. Stored procedures usually collect and customize common operations, like inserting a tuple into a relation, gathering statistical information about usage patterns, or encapsulating complex business logic and calculations. Frequently they are used as an application programming interface (API) for security or simplicity. Implementations of stored procedures on SQL RDBMS's often allow developers to take advantage of procedural extensions (often vendor-specific) to the standard declarative SQL syntax.

Instead of translating directly into machine code, modern compilers translate to a machine independent intermediate code in order to enhance portability of the compiler and minimize design efforts. The intermediate language defines a virtual machine that can execute all programs written in the intermediate language (a machine is defined by its language and vice versa). describes the terms and their relations. The intermediate code instructions are translated into equivalent machine code sequences by a code generator to create executable code.

Additionally language lines within a block are normally indented for clarity, though this not required as white space is ignored. Each grammatically conforming text represents a collection of executable code and associated data which can be used by a Charm tool set as a component when assembling a program that can be run under an operating system utilising the services it provides to do useful work such as data processing or interacting with users through a graphical user interface (GUI).

Many anti-spyware applications can detect some software based keyloggers and quarantine, disable or cleanse them. However, because many keylogging programs are legitimate pieces of software under some circumstances, anti-spyware often neglects to label keylogging programs as spyware or a virus. These applications can detect software-based keyloggers based on patterns in executable code, heuristics and keylogger behaviors (such as the use of hooks and certain APIs). No software- based anti-spyware application can be 100% effective against all keyloggers.

It was possible to port Copylock to the PC because the x86 microprocessor supports the trace vector the same as the 68000 processor does, through a single-step interrupt or INT 1. It manifested itself in a slightly different way in that the game's executable code was encrypted and "wrapped" by the Copylock loader. At runtime this loader would read 4 sectors from the floppy, and generate checksums from them. These in turn would be used as the keys to decrypt the game code.

A function pointer, also called a subroutine pointer or procedure pointer, is a pointer that points to a function. As opposed to referencing a data value, a function pointer points to executable code within memory. Dereferencing the function pointer yields the referenced function, which can be invoked and passed arguments just as in a normal function call. Such an invocation is also known as an "indirect" call, because the function is being invoked indirectly through a variable instead of directly through a fixed identifier or address.

Before LZMA2 encoding, depending on the options provided, xz can apply the BCJ filter, which filters executable code to replace relative offsets with absolute ones that are more repetitive, or the delta filter, which replaces each byte with the difference between it and the byte bytes before it. Parallel encoding is performed by dividing the file in chunks which are distributed to threads, and ultimately each encoded (using, for instance, xz block encoding) separately, resulting in a dictionary reset between chunks in the output file.

This required loading only one copy into memory, saving both space and the time it took to load the code. Another reason to separate code and data into different load entities was that memory was implemented as two independent banks (separate physical cabinets) called IBANK and DBANK (instruction and data). Each had its own access path, so the CPU could read both banks simultaneously. By loading executable code into one memory bank and data into the other, the run time of many programs could be almost halved.

This means that newer computer hardware and/or software has (practically) every feature of the old, plus additional capabilities or performance. Older executable code will thus run unchanged on the newer product. For a compiled program running directly on a CPU under an OS, a "binary compatible operating system" primarily means application binary interface (ABI) compatibility with another system. However, it also often implies that APIs that the application depends on, directly or indirectly (such as the Windows API, for example), are sufficiently similar.

The basic data structure of Forth is the "dictionary" which maps "words" to executable code or named data structures. The dictionary is laid out in memory as a tree of linked lists with the links proceeding from the latest (most recently) defined word to the oldest, until a sentinel value, usually a NULL pointer, is found. A context switch causes a list search to start at a different leaf. A linked list search continues as the branch merges into the main trunk leading eventually back to the sentinel, the root.

Relocatable Dynamic Object File Format (RDOFF) is used by developers to test the integrity of NASM's object file output abilities. It is based heavily on the internal structure of NASM, essentially consisting of a header containing a serialization of the output driver function calls followed by an array of sections containing executable code or data. Tools for using the format, including a linker and loader, are included in the NASM distribution. Until version 0.90 was released in October 1996, NASM supported output of only flat- format executable files (e.g.

This is due to the active nature of the network in which communication packets contain code that dynamically change the operation of the network. Fundamental advances in information theory are required in order to understand such networks. An active network channel uses executable code in the packet to impact the channel controlling the relationship between the transmitted sequence X and the received sequence Y. X is composed of a data portion X^{data} and a code portion X^{code}. Upon incorporation of X^{code}, the channel medium may change its operational state and capabilities.

The Portable Executable (PE) format is a file format for executables, object code, DLLs and others used in 32-bit and 64-bit versions of Windows operating systems. The PE format is a data structure that encapsulates the information necessary for the Windows OS loader to manage the wrapped executable code. This includes dynamic library references for linking, API export and import tables, resource management data and thread-local storage (TLS) data. On NT operating systems, the PE format is used for EXE, DLL, SYS (device driver), and other file types.

Throughout 2016 and 2017, Emotet operators updated the trojan and reconfigured it to work primarily as a "loader," a type of malware that gains access to a system, and then allows its operators to download additional payloads. Second-stage payloads can be any type of executable code, from Emotet's own modules to malware developed by other cybercrime gangs. Initial infection of target systems often proceeds through a macro virus in an email attachment. The infected email is a legitimate-appearing reply to an earlier message that was sent by the victim.

Tagging is a compiler-based or hardware-based (requiring a tagged architecture) technique for tagging the type of a piece of data in memory, used mainly for type checking. By marking certain areas of memory as non-executable, it effectively prevents memory allocated to store data from containing executable code. Also, certain areas of memory can be marked as non-allocated, preventing buffer overflows. Historically, tagging has been used for implementing high-level programming languages; with appropriate support from the operating system, tagging can also be used to detect buffer overflows.

Instead, it exploited security holes (vulnerabilities) in network server programs and started itself running as a separate process. This same behavior is used by today's worms as well. With the rise of the Microsoft Windows platform in the 1990s, and the flexible macros of its applications, it became possible to write infectious code in the macro language of Microsoft Word and similar programs. These macro viruses infect documents and templates rather than applications (executables), but rely on the fact that macros in a Word document are a form of executable code.

A callback is often back on the level of the original caller. In computer programming, a callback, also known as a "call-after" function, is any executable code that is passed as an argument to other code; that other code is expected to call back (execute) the argument at a given time. This execution may be immediate as in a synchronous callback, or it might happen at a later time as in an asynchronous callback. Programming languages support callbacks in different ways, often implementing them with subroutines, lambda expressions, blocks, or function pointers.

A hex dump of an executable real mode loader In computing, executable code, executable file, or executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instructions", as opposed to a data file that must be parsed by a program to be meaningful. The exact interpretation depends upon the use. "Instructions" is traditionally taken to mean machine code instructions for a physical CPU. In some contexts, a file containing bytecode or scripting instructions may also be considered executable.

Often, these tiny languages can be used together inside a shell to perform more complex programming tasks. The line between domain-specific languages and scripting languages is somewhat blurred, but domain-specific languages often lack low- level functions for filesystem access, interprocess control, and other functions that characterize full-featured programming languages, scripting or otherwise. Many domain-specific languages do not compile to byte-code or executable code, but to various kinds of media objects: GraphViz exports to PostScript, GIF, JPEG, etc., where Csound compiles to audio files, and a ray- tracing domain-specific language like POV compiles to graphics files.

A single file format, such as 7z, can support multiple different compression algorithms including LZMA, LZMA2, PPMd and BZip2. For a decompression utility to correctly expand an archive of either the self-extracting or standard variety, it must be able to operate on both the file format and algorithm used. The exact executable code placed at the beginning of a self-extracting archive may therefore need to be varied depending on what options were used to create the archive. The decompression routines will be different for a LZMA 7z archive when compared with a LZMA2 7z archive, for example.

CP/M-86 and DOS do not share a common file extension for executables. Thus, it is not normally possible to confuse executables. However, early versions of DOS had so much in common with CP/M in terms of its architecture that some early DOS programs were developed to share binaries containing executable code. One program known to do this was WordStar 3.2x, which used identical overlay files in their ports for CP/M-86 and MS-DOS, and used dynamically fixed-up code to adapt to the differing calling conventions of these operating systems at runtime.

HP's RPL, first introduced in the HP-18C calculator in 1986, is a type of proprietary hybrid direct-threaded and indirect-threaded threaded-interpreted language that, unlike others TILs, allows embedding of RPL "objects" into the "runstream" ie. The stream of addresses through which the interpreter pointer advances. An RPL "object" can be thought of as a special data type whose in-memory structure contains an address to an "object prolog" at the start of the object, and then data or executable code follows. The object prolog determines how the object's body should be executed or processed.

In June 2009, Manomio submitted a Commodore 64 emulator to the iPhone App Store; the application was rejected due to the use of interpreted or executable code. The emulator was finally accepted in early September, although it was removed from the App Store two days later because it was discovered to have the capability for users to run and create BASIC programs. Prior to its removal, the Commodore 64 emulator app had risen into the top 20 in the "paid apps" section, after only two days of sales. Manomio quickly submitted a new version of the application without BASIC capabilities.

Software can be compiled and linked from source code for different operating systems and processors if written in a programming language supporting compilation for the platforms. This is usually a task for the program developers; typical users have neither access to the source code nor the required skills. In open-source environments such as Linux the source code is available to all. In earlier days source code was often distributed in a standardised format, and could be built into executable code with a standard Make tool for any particular system by moderately knowledgeable users if no errors occurred during the build.

The reference open source LZMA compression library was originally written in C++ but has been ported to ANSI C, C#, and Java. There are also third-party Python bindings for the C++ library, as well as ports of LZMA to Pascal, Go and Ada. The 7-Zip implementation uses several variants of hash chains, binary trees and Patricia tries as the basis for its dictionary search algorithm. In addition to LZMA, the SDK and 7-Zip also implements multiple preprocessing filters intended to improve compression, ranging from simple delta encoding (for images) and BCJ for executable code.

The cost in terms of theoretical purity is high, but practical inconvenience seems to be rare. Other programs that undertake to parse Perl, such as source-code analyzers and auto-indenters, have to contend not only with ambiguous syntactic constructs but also with the undecidability of Perl parsing in the general case. Adam Kennedy's PPI project focused on parsing Perl code as a document (retaining its integrity as a document), instead of parsing Perl as executable code (that not even Perl itself can always do). It was Kennedy who first conjectured that "parsing Perl suffers from the 'halting problem'," which was later proved.

Secunia PSI is an example of software, free for personal use, that will check a PC for vulnerable out-of-date software, and attempt to update it. Malware authors target bugs, or loopholes, to exploit. A common method is exploitation of a buffer overrun vulnerability, where software designed to store data in a specified region of memory does not prevent more data than the buffer can accommodate being supplied. Malware may provide data that overflows the buffer, with malicious executable code or data after the end; when this payload is accessed it does what the attacker, not the legitimate software, determines.

Some software is licensed with a copy of the program source code supplied along with the executable code in which the license specifically authorizes changes to the supplied software. This is a common standard in business software packages. Hundreds of thousands of computer programmers in some nations have jobs because businesses want the purchased software tailored to the specific needs of the individual businesses. Most every major city has want ads in the newspaper where there are job openings for people to modify some company's computer systems, where the ad specifies what programming languages or operating systems the applicant needs to know.

Reentrant code had to be thread safe (execute only); self-modifying code was not allowed. For other programs, modifying executable code during runtime was still an acceptable programming technique in the time of 1100-series computers, but users were encouraged not to do it because of the performance hit. Security benefits were touted but not highly valued because hacking most 1100-series applications would provide no benefit to anyone, and because few hackers were malevolent then. Exec 8 was primarily a batch processing system that gave applications (called "tasks") very fine control of CPU scheduling priority for its threads (called "activities").

This allows authors of modern games to ship one file containing everything needed to play the game, while also allowing the creation of resource files for classic Infocom games without running the risk of copyright infringement by distributing Infocom's Z-machine executable code. Glulx games are almost always shipped in the Blorb format. A rather smaller proportion of Z-machine games make use of it, since Z-machine games often rely only on text, and so have no need for the extra resources. As of 2004 Blorb files are supported by all Glk interactive fiction interpreters, including Nitfol and Glulxe.

The earliest microcomputers, such as the Altair 8800 (released first in 1975) and an even earlier, similar machine (based on the Intel 8008 CPU) had no bootstrapping hardware as such. When started, the CPU would see memory that would contain executable code containing only binary zeros—memory was cleared by resetting when powering up. The front panels of these machines carried toggle switches for entering addresses and data, one switch per bit of the computer memory word and address bus. Simple additions to the hardware permitted one memory location at a time to be loaded from those switches to store bootstrap code.

FUD is widely recognized as a tactic to promote the sale or implementation of security products and measures. It is possible to find pages describing purely artificial problems. Such pages frequently contain links to the demonstrating source code that does not point to any valid location and sometimes even links that "will execute malicious code on your machine regardless of current security software", leading to pages without any executable code. The drawback to the FUD tactic in this context is that, when the stated or implied threats fail to materialize over time, the customer or decision-maker frequently reacts by withdrawing budgeting or support from future security initiatives.

In computer programming, glue code is executable code (often source code) that serves solely to "adapt" different parts of code that would otherwise be incompatible. Glue code does not contribute any functionality towards meeting program requirements. Instead, it often appears in code that lets existing libraries or programs interoperate, as in language bindings or foreign function interfaces such as the Java native interface, when mapping objects to a database using object-relational mapping, or when integrating two or more commercial off-the-shelf programs. Glue code may be written in the same language as the code it is gluing together, or in a separate glue language.

Somewhat more unusual than memory editing, code injection consists of the modification of the game's executable code while it is running, for example with the use of POKE commands. In the case of Jet Set Willy on the ZX Spectrum computer, a popular cheat involved replacing a Z80 instruction `DEC (HL)` in the program (which was responsible for decrementing the number of lives by one) with a `NOP`, effectively granting the player infinite lives. On Microsoft Windows, a common type of video game hacking is through the use of DLLs. Users use a third party program to inject the DLL into their game of choice.

A master boot record (MBR) is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond. The concept of MBRs was publicly introduced in 1983 with PC DOS 2.0. The MBR holds the information on how the logical partitions, containing file systems, are organized on that medium. The MBR also contains executable code to function as a loader for the installed operating system—usually by passing control over to the loader's second stage, or in conjunction with each partition's volume boot record (VBR).

At the lowest programming level, executable code consists of machine language instructions supported by an individual processor—typically a central processing unit (CPU) or a graphics processing unit (GPU). A machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction may also invoke one of many input or output operations, for example displaying some text on a computer screen; causing state changes which should be visible to the user.

Track0 (pronounced 'track zero') is the area located at the start of a computer disk and is predominantly used to store information regarding the layout of the disk (the partition table) and executable code needed to boot an operating system. Track0 typically consists of the first 64 sectors of the disk (since each sector is normally 512 bytes, this corresponds to 32,768 bytes = 32KiB). Since the first sector of a disk is sector zero, the first 64 sectors are sectors 0 to 63. The first sector of Track0 is known as the master boot record (MBR) and contains the initial code used to boot the operating system (bootstrap code).

Research has found that UC Browser is insecure, with many vulnerabilities and privacy issues. In March 2019, analysts at the anti- malware firm Doctor Web publicly disclosed that UC Browser and UC Browser Mini for Android was downloading and installing extra modules from the company's own servers via an unprotected HTTP channel. This exposed browser users to arbitrary remote code execution if an attacker was able to perform a man-in- the-middle attack to deliver malicious module (but no cases of exploitation were publicly disclosed). Furthermore, this violates Google Play policies that forbid Google Play apps from downloading any executable code from any sources outside of Google Play.

Exploiting the behavior of a buffer overflow is a well- known security exploit. On many systems, the memory layout of a program, or the system as a whole, is well defined. By sending in data designed to cause a buffer overflow, it is possible to write into areas known to hold executable code and replace it with malicious code, or to selectively overwrite data pertaining to the program's state, therefore causing behavior that was not intended by the original programmer. Buffers are widespread in operating system (OS) code, so it is possible to make attacks that perform privilege escalation and gain unlimited access to the computer's resources.

In the days when games were distributed only on disk, there was no problem in associating a game with its resources: the resources were simply shipped on the same disk. Since all Z-machine games were produced by Infocom, there was also no chance that resources would be shipped in a format which a user's interpreter program could not handle. Blorb is needed because neither of these assumptions hold true in modern times: games are typically downloaded as single files, and a user may be using any of a large number of interpreters. A Blorb file may optionally include the executable code of the game itself.

The Arduino IDE supplies a software library from the Wiring project, which provides many common input and output procedures. User-written code only requires two basic functions, for starting the sketch and the main program loop, that are compiled and linked with a program stub main() into an executable cyclic executive program with the GNU toolchain, also included with the IDE distribution. The Arduino IDE employs the program avrdude to convert the executable code into a text file in hexadecimal encoding that is loaded into the Arduino board by a loader program in the board's firmware. By default, avrdude is used as the uploading tool to flash the user code onto official Arduino boards.

A process with two threads of execution, running on one processor In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. The implementation of threads and processes differs between operating systems, but in most cases a thread is a component of a process. Multiple threads can exist within one process, executing concurrently and sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non-thread-local global variables at any given time.

Overfilling a buffer on the stack is more likely to derail program execution than overfilling a buffer on the heap because the stack contains the return addresses for all active function calls. Stack buffer overflow can be caused deliberately as part of an attack known as stack smashing. If the affected program is running with special privileges, or if it accepts data from untrusted network hosts (for example, a public webserver), then the bug is a potential security vulnerability that allows an attacker to inject executable code into the running program and take control of the process. This is one of the oldest and more reliable methods for attackers to gain unauthorized access to a computer.

Some computer architectures still reserve the beginning of address space for other purposes, though; for instance, Intel x86 systems reserve the first 256 double-words of address space for the interrupt vector table (IVT) if they run in real mode. A similar technique of using the zero page for hardware related vectors was employed in the ARM architecture. In badly written programs this could lead to "ofla" behaviour, where a program tries to read information from an unintended memory area, and treats executable code as data or vice versa. This is especially problematic if the zero page area is used to store system jump vectors and the firmware is tricked into overwriting them.

Files that contain machine- executable code and non-textual data typically contain all 256 possible eight- bit byte values. Many computer programs came to rely on this distinction between seven-bit text and eight-bit binary data, and would not function properly if non-ASCII characters appeared in data that was expected to include only ASCII text. For example, if the value of the eighth bit is not preserved, the program might interpret a byte value above 127 as a flag telling it to perform some function. It is often desirable, however, to be able to send non- textual data through text-based systems, such as when one might attach an image file to an e-mail message.

The C programming language manages memory statically, automatically, or dynamically. Static-duration variables are allocated in main memory, usually along with the executable code of the program, and persist for the lifetime of the program; automatic-duration variables are allocated on the stack and come and go as functions are called and return. For static-duration and automatic-duration variables, the size of the allocation must be compile-time constant (except for the case of variable- length automatic arrays). If the required size is not known until run-time (for example, if data of arbitrary size is being read from the user or from a disk file), then using fixed-size data objects is inadequate.

Stuxnet attacked Windows systems using an unprecedented four zero-day attacks (plus the CPLINK vulnerability and a vulnerability used by the Conficker worm). It is initially spread using infected removable drives such as USB flash drives, which contain Windows shortcut files to initiate executable code. The worm then uses other exploits and techniques such as peer-to-peer remote procedure call (RPC) to infect and update other computers inside private networks that are not directly connected to the Internet. The number of zero-day exploits used is unusual, as they are highly valued and malware creators do not typically make use of (and thus simultaneously make visible) four different zero-day exploits in the same worm.

Unlike DVDs and computer games, broadcast radio and television programs contain no executable code. Easter eggs may still appear in the content itself, such as a hidden Mickey in a Disney film or a real telephone number instead of a 555 fictitious telephone number. A 2014 Super Bowl advertisement was leaked online in which a lady gives a man a real telephone number, which the advertiser had hidden as a marketing ploy; the first caller to the number received a pair of tickets to the game. The 1980s animated series She-Ra: Princess of Power featured a character called Loo-Kee who typically appeared once per episode, hidden in a single screenshot.

In computer science a quine is a self-reproducing computer program that, when executed, outputs its own code. For example, a quine in the Python programming language is: :`a='a=%r;print(a%%a)';print(a%a)` A more trivial approach is to write a program that will make a copy of any stream of data that it is directed to, and then direct it at itself. In this case the program is treated as both executable code, and as data to be manipulated. This approach is common in most self-replicating systems, including biological life, and is simpler as it does not require the program to contain a complete description of itself.

In a typical system, the firmware (or operating system) queries all PCI buses at startup time (via PCI Configuration Space) to find out what devices are present and what system resources (memory space, I/O space, interrupt lines, etc.) each needs. It then allocates the resources and tells each device what its allocation is. The PCI configuration space also contains a small amount of device type information, which helps an operating system choose device drivers for it, or at least to have a dialogue with a user about the system configuration. Devices may have an on-board ROM containing executable code for x86 or PA-RISC processors, an Open Firmware driver, or an EFI driver.

LexisNexis also implemented a new high-level language for data-intensive computing. The ECL programming language is a high-level, declarative, data-centric, implicitly parallel language that allows the programmer to define what the data processing result should be and the dataflows and transformations that are necessary to achieve the result. The ECL language includes extensive capabilities for data definition, filtering, data management, and data transformation, and provides an extensive set of built-in functions to operate on records in datasets which can include user- defined transformation functions. ECL programs are compiled into optimized C++ source code, which is subsequently compiled into executable code and distributed to the nodes of a processing cluster.

Binary-code compatibility (binary compatible or object-code-compatible) is a property of computer systems meaning that they can run the same executable code, typically machine code for a general-purpose computer CPU. Source-code compatibility, on the other hand, means that recompilation or interpretation is necessary before the program can be run. For a compiled program on a general operating system, binary compatibility often implies that not only the CPUs (instruction sets) of the two computers are binary compatible, but also that interfaces and behaviours of the operating system and APIs, and the ABIs corresponding to those APIs, are sufficiently equal, i.e. "compatible". A term like backward-compatible usually implies object-code compatibility.

FreeBSD, on the other hand, extended ptrace to remove mentioned problems, and declared procfs obsolete due to its inherent design problems. ptrace only provides the most basic interface necessary to support debuggers and similar tools. Programs using it must have intimate knowledge of the specifics of the OS and architecture, including stack layout, application binary interface, system call mechanism, name mangling, the format of any debug data, and are responsible for understanding and disassembling machine code themselves. Further, programs that inject executable code into the target process or (like gdb) allow the user to enter commands that are executed in the context of the target must generate and load that code themselves, generally without the help of the program loader.

A file inclusion vulnerability is a type of web vulnerability that is most commonly found to affect web applications that rely on a scripting run time. This issue is caused when an application builds a path to executable code using an attacker-controlled variable in a way that allows the attacker to control which file is executed at run time. A file include vulnerability is distinct from a generic directory traversal attack, in that directory traversal is a way of gaining unauthorized file system access, and a file inclusion vulnerability subverts how an application loads code for execution. Successful exploitation of a file inclusion vulnerability will result in remote code execution on the web server that runs the affected web application.

Turing attempted to convert the program into executable code for the 1951 Ferranti Mark 1 computer in Manchester, but was unable to do so. Turing played a match against computer scientist Alick Glennie using the program in the summer of 1952, executing it manually step by step, but by his death in 1954 had still been unable to run the program on an actual computer. Champernowne did not continue the project, and the original program design was not preserved. Despite never being run on a computer, the program is a candidate for the first chess program; several other chess programs were designed or proposed around the same time, including another one which Turing unsuccessfully tried to run on the Ferranti Mark 1.

IBM i programs, like System/38 programs before them, contain both processor-independent "virtual" binary code and processor-dependent executable binary code. Compilers for IBM i produce the processor-independent code as their output; the operating system automatically translates the processor-independent code into the processor-dependent code as needed, without the need for source code or attention by IT personnel. Notably, when migrating from a legacy processor (for example, from CISC to RISC hardware), if automatic migration is configured and if the original program was created with normal options, the system will rebuild the executable code automatically and in just a few seconds. Migration consists of taking a backup from the old computer, and restoring it on the new.

Instead of separating the code from the data, another mitigation technique is to introduce randomization to the memory space of the executing program. Since the attacker needs to determine where executable code that can be used resides, either an executable payload is provided (with an executable stack) or one is constructed using code reuse such as in ret2libc or return-oriented programming (ROP). Randomizing the memory layout will, as a concept, prevent the attacker from knowing where any code is. However, implementations typically will not randomize everything; usually the executable itself is loaded at a fixed address and hence even when ASLR (address space layout randomization) is combined with a nonexecutable stack the attacker can use this fixed region of memory.

Unlike other integrated products Framework was not created as "plug-in" modules with similar look and feel but as a single windowing workspace representing a desktop metaphor that could manage and outline "Frames" sharing a common underlying format. The initial release included about a dozen or so frame types (identified by a FRED function, @frametype). Frame types included containers which could be filled up with other frames, empty frames which could become other type of frames based on user input, formulas embedded in them or program output targeting them, word processor frames, flat-database frames and spreadsheet as well as graphic frames. Later versions included a frame type that can hold compiled executable code and the current version include an external type handled by separate applications running on the host operating system.

In information security and programming, a buffer overflow, or buffer overrun, is an anomaly where a program, while writing data to a buffer, overruns the buffer's boundary and overwrites adjacent memory locations. Buffers are areas of memory set aside to hold data, often while moving it from one section of a program to another, or between programs. Buffer overflows can often be triggered by malformed inputs; if one assumes all inputs will be smaller than a certain size and the buffer is created to be that size, then an anomalous transaction that produces more data could cause it to write past the end of the buffer. If this overwrites adjacent data or executable code, this may result in erratic program behavior, including memory access errors, incorrect results, and crashes.

Typically, buffer overflow protection modifies the organization of stack-allocated data so it includes a canary value that, when destroyed by a stack buffer overflow, shows that a buffer preceding it in memory has been overflowed. By verifying the canary value, execution of the affected program can be terminated, preventing it from misbehaving or from allowing an attacker to take control over it. Other buffer overflow protection techniques include bounds checking, which checks accesses to each allocated block of memory so they cannot go beyond the actually allocated space, and tagging, which ensures that memory allocated for storing data cannot contain executable code. Overfilling a buffer allocated on the stack is more likely to influence program execution than overfilling a buffer on the heap because the stack contains the return addresses for all active function calls.

Software distributors use executable compression for a variety of reasons, primarily to reduce the secondary storage requirements of their software; as executable compressors are specifically designed to compress executable code, they often achieve better compression ratio than standard data compression facilities such as gzip, zip or bzip2 . This allows software distributors to stay within the constraints of their chosen distribution media (such as CD-ROM, DVD-ROM, or Floppy disk), or to reduce the time and bandwidth customers require to access software distributed via the Internet. Executable compression is also frequently used to deter reverse engineering or to obfuscate the contents of the executable (for example, to hide the presence of malware from antivirus scanners) by proprietary methods of compression and/or added encryption. Executable compression can be used to prevent direct disassembly, mask string literals and modify signatures.

COM is a binary image containing executable code rather than a true COM-style program, the hidden attribute is set to keep the file from being accidentally invoked at the command prompt, which would lead to a crash. This is not necessary for DR-DOS 7.02 and higher, because under these systems the file is a fat binary also containing a tiny COM-style stub just displaying some version info and exiting gracefully when loaded inappropriately. In Digital Research terminology, the kernel component of the operating system is called the BDOS (Basic Disk Operating System), a term originally coined by Gary Kildall in 1975 for CP/M, but which is continued to be used in all other DRI operating systems (except for Concurrent DOS 286 and FlexOS). Microsoft has used this name as well when referring to the kernel of the MSX-DOS operating system.

It does not indicate the presence of a (or even a particular) file system or operating system, although some old versions of DOS prior to 3.3 relied on it in their process to detect FAT-formatted media (newer versions do not). Boot code for other platforms or CPUs should not use this signature, since this may lead to a crash when the BIOS passes execution to the boot sector assuming that it contains valid executable code. This implies that FAT12/FAT16 media to be used also by very old versions of DOS must maintain the signature even if they do not contain an operating system or are meant to be bootable on other platforms only; consequently they must contain at least an x86 compatible (dummy) loader as well (for comparison, see examples of FAT on the Atari ST and with MSX-DOS). Nevertheless, some media for other platforms erroneously contain the signature even without a x86 compatible dummy loader, making the check not 100% reliable in practice.

McBBS started out as a project for the then High School student Derek McDonald, then attending Charles P. Allen High School in Bedford, Nova Scotia, Canada. As an aspiring young programmer, and unhappy with the software available to him at the time, he set out to prove he could build his own stable computer communications system as a personal project. Heavily influenced by the works of Ken Spence and his Spence XP BBS system of which there were two versions written in 1985 and 1987 respectively, as well as Ed Parry's EBBS and Clarke Development's PCBoard, the McBBS software was originally developed for the Commodore 64 computer but was ported over to the DOS platform in 1992 (starting with McBBS v3.0) where it remained until the project was officially ended in May 2000. The software was written entirely in the BASIC computer language, but starting with version 3.1 in 1992 it was compiled from BASIC into 8086 executable code for DOS.

Near the anticipated completion date, 2K decided to give Irrational another three months to polish up the game, extending the current crunch time the studio was already under. This left some hard-to-discover bugs and issues in the game undiscovered. One such case was an apparent Easter egg found in the remastered version in 2018, where under certain conditions, the player can end up looking at an object with the description "Paul Hellquist did not do his Job". Both Levine and Chris Kline, the game's lead programmer confirmed the message was a cheeky jab at Hellquist left as a debugging message; Kline and Hellquist were developing the systems to show descriptions of objects to players when looked at, and Hellquist offered to complete all the necessary descriptions in-game; to jokingly help prod Hellquist along, Kline put "Paul Hellquist did not do his Job" as the default message within the executable code.

Mark Shuttleworth, the founder of the company Canonical, which maintains the Ubuntu Linux distribution, has described proprietary firmware as a security risk, saying that "firmware on your device is the NSA's best friend" and calling firmware "a trojan horse of monumental proportions". He has asserted that low-quality, closed source firmware is a major threat to system security:Linux Magazine issue 162, May 2014, page 9 "Your biggest mistake is to assume that the NSA is the only institution abusing this position of trust in fact, it's reasonable to assume that all firmware is a cesspool of insecurity, courtesy of incompetence of the highest degree from manufacturers, and competence of the highest degree from a very wide range of such agencies". As a potential solution to this problem, he has called for declarative firmware, which would describe "hardware linkage and dependencies" and "should not include executable code". Firmware should be open-source so that the code can be checked and verified.

For example, the instruction set specifications of a CPU might leave the behavior of some forms of an instruction undefined, but if the CPU supports memory protection then the specification will probably include a blanket rule stating that no user-accessible instruction may cause a hole in the operating system's security; so an actual CPU would be permitted to corrupt user registers in response to such an instruction, but would not be allowed to, for example, switch into supervisor mode. The runtime platform can also provide some restrictions or guarantees on undefined behavior, if the toolchain or the runtime explicitly document that specific constructs found in the source code are mapped to specific well-defined mechanisms available at runtime. For example, an interpreter may document a certain behavior for some operations that are undefined in the language specification, while other interpreters or compilers for the same language may not. A compiler produces executable code for a specific ABI, filling the semantic gap in ways that depend on the compiler version: the documentation for that compiler version and the ABI specification can provide restrictions on undefined behavior.

Noting that the ways to conquer the complexity of program translation could readily be applied to protocols because of the analogy between programming languages and protocols, the designers of the TCP/IP protocol suite were keen on imposing the same layering on the software framework. This can be seen in the TCP/IP layering by considering the translation of a pascal program (message) that is compiled (function of the application layer) into an assembler program that is assembled (function of the transport layer) to object code (pieces) that is linked (function of the Internet layer) together with library object code (routing table) by the link editor, producing relocatable machine code (datagram) that is passed to the loader which fills in the memory locations (ethernet addresses) to produce executable code (network frame) to be loaded (function of the network interface layer) into physical memory (transmission medium). To show just how closely the analogy fits, the terms between parentheses in the previous sentence denote the relevant analogs and the terms written cursively denote data representations. Program translation forms a linear sequence because each layer's output is passed as input to the next layer.