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Libc
The C standard library, sometimes referred to as libc, is the standard library for the C programming language, as specified in the ISO C standard.ISO/ IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. Since ANSI C was adopted by the International Organization for Standardization, the C standard library is also called the ISO C library. The C standard library provides macros, type definitions and functions for tasks such as string manipulation, mathematical computation, input/output processing, memory management, and input/output. Application programming interface (API) Header files The application programming interface (API) of the C standard library is declared in a number of header files. Each header file contains one or more function declarations, data type definitions, and macros. After a long period of stability, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Mathematical Functions
C mathematical operations are a group of functions in the standard library of the C programming language implementing basic mathematical functions. Different C standards provide different, albeit backwards-compatible, sets of functions. Most of these functions are also available in the C++ standard library, though in different headers (the C headers are included as well, but only as a deprecated compatibility feature). Overview of functions Most of the mathematical functions, which use floating-point numbers, are defined in ( header in C++). The functions that operate on integers, such as abs, labs, div, and ldiv, are instead defined in the header ( header in C++). Any functions that operate on angles use radians as the unit of angle. Not all of these functions are available in the C89 version of the standard. For those that are, the functions accept only type double for the floating-point arguments, leading to expensive type conversions in code that otherwise used sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Errno
errno.h is a header file in the standard library of the C programming language. It defines macros for reporting and retrieving error conditions using the symbol errno (short form for "error number").International Standard for Programming Language C (C11), ISO/IEC 9899:2011, p. 205 errno acts like an integer variable. A value (the error number) is stored in errno by certain library functions when they detect errors. At program startup, the value stored is zero. Library functions store only values greater than zero. Any library function can alter the value stored before return, whether or not they detect errors.International Standard for Programming Language C (C99), ISO/IEC 9899:1999, p. 186 Most functions indicate that they detected an error by returning a special value, typically NULL for functions that return pointers, and -1 for functions that return integers. A few functions require the caller to preset errno to zero and test it afterwards to see if an error was detected. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of Resource management (computing), resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single Process (computing), process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of Random-access memory, RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C23 (C Standard Revision)
C23, formally ISO/IEC 9899:2024, is the current open standard for the C programming language, which supersedes C17 (standard ISO/IEC 9899:2018). It was started in 2016 informally as C2x, and was published on October 31, 2024. The freely available draft most similar to the one published is document N3220 (see Available texts, below). The first WG14 meeting for the C2x draft was held in October 2019, virtual remote meetings were held in 2020 due to the COVID-19 pandemic, then various teleconference meetings continued to occur through 2024. In C23, the value of __STDC_VERSION__ changes from 201710L to 202311L. The common names "C17" and "C23" reflect these values, which are frozen prior to final adoption, rather than the years in the ISO standards identifiers (9899:2018 and 9899:2024). Features Changes integrated into the latest working draft of C23 are listed below. Standard Library New functions * Add memset_explicit() function in to erase sensitive data, where memory stor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assertion (computing)
In computer programming, specifically when using the imperative programming paradigm, an assertion is a predicate (a Boolean-valued function over the state space, usually expressed as a logical proposition using the variables of a program) connected to a point in the program, that always should evaluate to true at that point in code execution. Assertions can help a programmer read the code, help a compiler compile it, or help the program detect its own defects. For the latter, some programs check assertions by actually evaluating the predicate as they run. Then, if it is not in fact true – an assertion failure – the program considers itself to be broken and typically deliberately crashes or throws an assertion failure exception. Details The following code contains two assertions, x > 0 and x > 1, and they are indeed true at the indicated points during execution: x = 1; assert x > 0; x++; assert x > 1; Programmers can use assertions to help specify programs and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Library
In computer programming, a standard library is the library (computing), library made available across Programming language implementation, implementations of a programming language. Often, a standard library is specified by its associated programming language specification, however, some are set in part or whole by more informal practices of a language community. Some languages define a core part of the standard library that must be made available in all implementations while allowing other parts to be implemented optionally. As defined with the core language aspects, the line between the core language and its standard library is relatively subtle. A programmer may confuse the two aspects even though the language designers intentionally separate the two. The line between the core language and its standard library is further blurred in some languages by defining core language constructs in terms of its standard library. For example, Java (programming language), Java defines a str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EBCDIC
Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight- bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six-bit binary-coded decimal code used with most of IBM's computer peripherals of the late 1950s and early 1960s. It is supported by various non-IBM platforms, such as Fujitsu-Siemens' BS2000/OSD, OS-IV, MSP, and MSP-EX, the SDS Sigma series, Unisys VS/9, Unisys MCP and ICL VME. History EBCDIC was devised in 1963 and 1964 by IBM and was announced with the release of the IBM System/360 line of mainframe computers. It is an eight-bit character encoding, developed separately from the seven-bit ASCII encoding scheme. It was created to extend the existing Binary-Coded Decimal (BCD) Interchange Code, or BCDIC, which itself was devised as an efficient means of encoding the two ''zone'' and ''number'' punches on punched cards into six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example, the first 128 code points of Unicode are the same as ASCII. ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits ''0'' to ''9'', lowercase letters ''a'' to ''z'', uppercase letters ''A'' to ''Z'', and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Character Set
Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical values that make up a character encoding are known as code points and collectively comprise a code space or a code page. Early character encodings that originated with optical or electrical telegraphy and in early computers could only represent a subset of the characters used in written languages, sometimes restricted to upper case letters, numerals and some punctuation only. Over time, character encodings capable of representing more characters were created, such as ASCII, the ISO/IEC 8859 encodings, various computer vendor encodings, and Unicode encodings such as UTF-8 and UTF-16. The most popular character encoding on the World Wide Web is UTF-8, which is used in 98.2% of surveyed web sites, as of May 2024. In application programs and operating syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Character Classification
C character classification is a group of operations in the C standard library that test a character for membership in a particular class of characters; such as alphabetic, control, etc. Both single-byte, and wide characters are supported. History Early C programmers working on the Unix operating system developed programming idioms for classifying characters. For example, the following code evaluates as ''true'' for an ASCII letter character c: ('A' <= c && c <= 'Z') , , ('a' <= c && c <= 'z') Eventually, the interface to common character classification functionality was codified in the C standard library file ''ctype.h''. Implementation For performance, the standard character classification functions are usually implemented as macros instead of functions. But, due to limitations of macro evaluation, they are generally not ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctype
Ctypes, ctype or another variant may refer to: Science * C-type natriuretic peptide * C-type lectin A C-type lectin (CLEC) is a type of carbohydrate-binding protein known as a lectin. The C-type designation is from their requirement for calcium for binding. Proteins that contain C-type lectin domains have a diverse range of functions including c ... * C-type star, or carbon star * C-type asteroid Software * ctypes, a form of language binding in Python and OCaml that can load C functions from shared libraries or DLLs on-the-fly * , a header in the ANSI C Standard Library for the C programming language that contains declarations for character classification functions Vehicles * Audi Type C, roadster * Citroën Type C, roadster * Jaguar C-Type, racing sports car * MG C-type, race car * Auto Union Type C, Grand Prix race car * Mercedes-Benz C-Class, sedan car * Renault C-Type engine, straight-4 car engine * C-type (New York City Subway car) * Handley Page Type C, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
