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Kdump (BSD)
ktrace is a utility included with certain versions of BSD Unix and Mac OS X that traces kernel interaction with a program and dumps it to disk for the purposes of debugging and analysis. Traced kernel operations include system calls, namei translations, signal processing, and I/O. Trace files generated by ktrace (named by default) can be viewed in human-readable form by using the kdump utility. Since Mac OS X Leopard, ktrace has been replaced by DTrace. See also * DTrace, Sun Microsystems's trace version, now running on OpenSolaris, FreeBSD, macOS, and Windows * kdump (Linux), Linux kernel's crash dump mechanism, which internally uses kexec * SystemTap * trace Trace may refer to: Arts and entertainment Music * Trace (Son Volt album), ''Trace'' (Son Volt album), 1995 * Trace (Died Pretty album), ''Trace'' (Died Pretty album), 1993 * Trace (band), a Dutch progressive rock band * The Trace (album), ''The ... on Linux, part of the Linux Trace Toolkit References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced like the letter c'') is a General-purpose language, general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems, device drivers, protocol stacks, though decreasingly for application software. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the measuring programming language popularity, most widely used programming languages, with C compilers avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BSD Unix
The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley. The term "BSD" commonly refers to its open-source descendants, including FreeBSD, OpenBSD, NetBSD, and DragonFly BSD. BSD was initially called Berkeley Unix because it was based on the source code of the original Unix developed at Bell Labs. In the 1980s, BSD was widely adopted by workstation vendors in the form of proprietary Unix variants such as DEC Ultrix and Sun Microsystems SunOS due to its permissive licensing and familiarity to many technology company founders and engineers. Although these proprietary BSD derivatives were largely superseded in the 1990s by UNIX SVR4 and OSF/1, later releases provided the basis for several open-source operating systems including FreeBSD, OpenBSD, NetBSD, DragonFly BSD, Darwin, and T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mac OS X
macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of desktop and laptop computers it is the Usage share of operating systems#Desktop and laptop computers, second most widely used desktop OS, after Microsoft Windows and ahead of ChromeOS. macOS succeeded the classic Mac OS, a Mac operating system with nine releases from 1984 to 1999. During this time, Apple cofounder Steve Jobs had left Apple and started another company, NeXT Computer, NeXT, developing the NeXTSTEP platform that would later be acquired by Apple to form the basis of macOS. The first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving later that year. All releases from Mac OS X Leopard, Mac OS X 10.5 Leopard and after are UNIX 03 certified, with an exception for OS X Lion, OS X 10. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Language
English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to the island of Great Britain. Existing on a dialect continuum with Scots, and then closest related to the Low Saxon and Frisian languages, English is genealogically West Germanic. However, its vocabulary is also distinctively influenced by dialects of France (about 29% of Modern English words) and Latin (also about 29%), plus some grammar and a small amount of core vocabulary influenced by Old Norse (a North Germanic language). Speakers of English are called Anglophones. The earliest forms of English, collectively known as Old English, evolved from a group of West Germanic (Ingvaeonic) dialects brought to Great Britain by Anglo-Saxon settlers in the 5th century and further mutated by Norse-speaking Viking settlers starting in the 8th and 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracing (software)
In software engineering, tracing involves a specialized use of logging to record information about a program's execution. This information is typically used by programmers for debugging purposes, and additionally, depending on the type and detail of information contained in a trace log, by experienced system administrators or technical-support personnel and by software monitoring tools to diagnose common problems with software. Tracing is a cross-cutting concern. There is not always a clear distinction between ''tracing'' and other forms of ''logging'', except that the term ''tracing'' is almost never applied to logging that is a functional requirement of a program (therefore excluding logging of data from an external source, such as data acquisition in a high-energy physics experiment, and write-ahead logging). Logs that record program usage (such as a server log) or operating-system events primarily of interest to a system administrator (see for example ''Event Viewer'') fal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility
As a topic of economics, utility is used to model worth or value. Its usage has evolved significantly over time. The term was introduced initially as a measure of pleasure or happiness as part of the theory of utilitarianism by moral philosophers such as Jeremy Bentham and John Stuart Mill. The term has been adapted and reapplied within neoclassical economics, which dominates modern economic theory, as a utility function that represents a single consumer's preference ordering over a choice set but is not comparable across consumers. This concept of utility is personal and based on choice rather than on pleasure received, and so is specified more rigorously than the original concept but makes it less useful (and controversial) for ethical decisions. Utility function Consider a set of alternatives among which a person can make a preference ordering. The utility obtained from these alternatives is an unknown function of the utilities obtained from each alternative, not the sum of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (operating System)
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the utilization of common resources e.g. CPU & cache usage, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usually loaded into a separate area of memory, which is protected from access by application ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugging
In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve interactive debugging, control flow analysis, unit testing, integration testing, log file analysis, monitoring at the application or system level, memory dumps, and profiling. Many programming languages and software development tools also offer programs to aid in debugging, known as ''debuggers''. Etymology The terms "bug" and "debugging" are popularly attributed to Admiral Grace Hopper in the 1940s. While she was working on a Mark II computer at Harvard University, her associates discovered a moth stuck in a relay and thereby impeding operation, whereupon she remarked that they were "debugging" the system. However, the term "bug", in the sense of "technical error", dates back at least to 1878 and Thomas Edison who describes the "litt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Call
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, accessing a hard disk drive or accessing the device's camera), creation and execution of new processes, and communication with integral kernel services such as process scheduling. System calls provide an essential interface between a process and the operating system. In most systems, system calls can only be made from userspace processes, while in some systems, OS/360 and successors for example, privileged system code also issues system calls. Privileges The architecture of most modern processors, with the exception of some embedded systems, involves a security model. For example, the ''rings'' model specifies multiple privilege levels under which software may be executed: a program is usually limited to its own address space so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Signal
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star. Computer scientists and mathematicians often vocalize it as star (as, for example, in ''the A* search algorithm'' or '' C*-algebra''). In English, an asterisk is usually five- or six-pointed in sans-serif typefaces, six-pointed in serif typefaces, and six- or eight-pointed when handwritten. Its most common use is to call out a footnote. It is also often used to censor offensive words. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication. History The asterisk has already been used as a symbol in ice age cave paintings. There is also a two thousand-year-old character used by Aristarchus of Samothrace called the , , which he used when proofreading Homeric poetry to mark lines that were duplicated. Origen i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mac OS X Leopard
Mac OS X Leopard (version 10.5) is the sixth software versioning, major release of macOS, Apple Inc., Apple's desktop and server operating system for Macintosh computers. Leopard was released on October 26, 2007 as the successor of Mac OS X Tiger, Mac OS X 10.4 Tiger, and is available in two editions: a Desktop computer, desktop version suitable for personal computers, and a Server (computing), server version, Mac OS X Server. It retailed for $129 for the desktop version and $499 for Server. Leopard was superseded by Mac OS X Snow Leopard, Snow Leopard (version 10.6) in 2009. Leopard is the final version of macOS to support the PowerPC architecture as Snow Leopard functions solely on Intel based Macs. According to Apple, Leopard contains over 300 changes and enhancements compared to its predecessor, Mac OS X Tiger, covering core operating system components as well as included applications and developer tools. Leopard introduces a significantly revised desktop, with a redesigned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTrace
DTrace is a comprehensive dynamic tracing framework originally created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. Originally developed for Solaris, it has since been released under the free Common Development and Distribution License (CDDL) in OpenSolaris and its descendant illumos, and has been ported to several other Unix-like systems. DTrace can be used to get a global overview of a running system, such as the amount of memory, CPU time, filesystem and network resources used by the active processes. It can also provide much more fine-grained information, such as a log of the arguments with which a specific function is being called, or a list of the processes accessing a specific file. In 2010, Oracle Corporation acquired Sun Microsystems and announced discontinuing OpenSolaris. As a community effort of some core Solaris engineers to create a truly open source Solaris, illumos operating system was announced vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
