|
Stdio.h
The C programming language provides many standard library functions for file input and output. These functions make up the bulk of the C standard library header . The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s, and officially became part of the Unix operating system in Version 7. The I/O functionality of C is fairly low-level by modern standards; C abstracts all file operations into operations on streams of bytes, which may be "input streams" or "output streams". Unlike some earlier programming languages, C has no direct support for random-access data files; to read from a record in the middle of a file, the programmer must create a stream, seek to the middle of the file, and then read bytes in sequence from the stream. The stream model of file I/O was popularized by Unix, which was developed concurrently with the C programming language itself. The vast majority of modern operating systems have inherited streams f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fseek
The C (programming language), C programming language provides many standard library subroutine, functions for computer file, file input/output, input and output. These functions make up the bulk of the C standard library header file, header . The functionality descends from a "portable I/O package" written by Mike Lesk at Bell Labs in the early 1970s, and officially became part of the Unix operating system in Version 7 Unix, Version 7. The I/O functionality of C is fairly low-level by modern standards; C abstracts all file operations into operations on stream (computing), streams of bytes, which may be "input streams" or "output streams". Unlike some earlier programming languages, C has no direct support for random access, random-access data files; to read from a record in the middle of a file, the programmer must create a stream, fseek, seek to the middle of the file, and then read bytes in sequence from the stream. The stream model of file I/O was popularized by Unix, which was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Standard Library
The C standard library, sometimes referred to as libc, is the standard library for the C (programming language), C programming language, as specified in the ISO C standard.International Organization for Standardization, ISO/International Electrotechnical Commission, IEC (2018). ''C17 (C standard revision), 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 macro (computer science), macros, Data type, type definitions and Function (computer programming), functions for tasks such as character string (computer science), string manipulation, mathematical computation, input/output processing, memory management, and input/output. Application programming interface (API) Header files The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose 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 Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. 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 most widely used programming langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Header File
An include directive instructs a text file processor to replace the directive text with the content of a specified file. The act of including may be logical in nature. The processor may simply process the include file content at the location of the directive without creating a combined file. Different processors may use different syntax. The C preprocessor (used with C, C++ and in other contexts) defines an include directive as a line that starts #include and is followed by a file specification. COBOL defines an include directive indicated by copy in order to include a copybook. Generally, for C/C++ the include directive is used to include a header file, but can include any file. Although relatively uncommon, it is sometimes used to include a body file such as a .c file. The include directive can support encapsulation and reuse. Different parts of a system can be segregated into logical groupings yet rely on one another via file inclusion. C and C++ are designed to leverag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Descriptor
In Unix and Unix-like computer operating systems, a file descriptor (FD, less frequently fildes) is a process-unique identifier (handle) for a file or other input/output resource, such as a pipe or network socket. File descriptors typically have non-negative integer values, with negative values being reserved to indicate "no value" or error conditions. File descriptors are a part of the POSIX API. Each Unix process (except perhaps daemons) should have three standard POSIX file descriptors, corresponding to the three standard streams: Overview In the traditional implementation of Unix, file descriptors index into a per-process maintained by the kernel, that in turn indexes into a system-wide table of files opened by all processes, called the . This table records the ''mode'' with which the file (or other resource) has been opened: for reading, writing, appending, and possibly other modes. It also indexes into a third table called the inode table that describes the ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Streams
In computer programming, standard streams are preconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin), standard output (stdout) and standard error (stderr). Originally I/O happened via a physically connected system console (input via keyboard, output via monitor), but standard streams abstract this. When a command is executed via an interactive shell, the streams are typically connected to the text terminal on which the shell is running, but can be changed with redirection or a pipeline. More generally, a child process inherits the standard streams of its parent process. Application Users generally know standard streams as input and output channels that handle data coming from an input device, or that write data from the application. The data may be text with any encoding, or binary data. When a program is run as a daemon, its stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sizeof
sizeof is a unary operator in the C and C++ programming languages that evaluates to the storage size of an expression or a data type, measured in units sized as char. Consequently, the expression sizeof(char) evaluates to 1. The number of bits of type char is specified by the preprocessor macro CHAR_BIT, defined in the standard include file limits.h. On most modern computing platforms this is eight bits. The result of ''sizeof'' is an unsigned integer that is usually typed as size_t. The operator accepts a single operand which is either a data type expressed as a cast the name of a data type enclosed in parentheses or a non-type expression for which parentheses are not required. Purpose Many programs must know the storage size of a particular datatype. Though for any given implementation of C or C++ the size of a particular datatype is constant, the sizes of even primitive types in C and C++ may be defined differently for different platforms of implementation. For ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mike Lesk
Michael E. Lesk (born 1945) is an American computer scientist. Biography In the 1960s, Michael Lesk worked for the SMART Information Retrieval System project, wrote much of its retrieval code and did many of the retrieval experiments, as well as obtaining a BA degree in Physics and Chemistry from Harvard College in 1964 and a PhD from Harvard University in Chemical Physics in 1969. From 1970 to 1984, Lesk worked at Bell Labs in the group that built Unix. Lesk wrote Unix tools for word processing ('' tbl'', '' refer'', and the standard ''ms'' macro package, all for ''troff''), for compiling ('' Lex''), and for networking (''uucp''). He also wrote the Portable I/O Library (the predecessor to stdio.h in C) and contributed significantly to the development of the C language preprocessor. In 1984, he left to work for Bellcore, where he managed the computer science research group. There, Lesk worked on specific information systems applications, mostly with geography (a system for dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Version 7 Unix
Version 7 Unix, also called Seventh Edition Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T Corporation in the early 1980s. V7 was originally developed for Digital Equipment Corporation's PDP-11 minicomputers and was later ported to other platforms. Overview Unix versions from Bell Labs were designated by the edition of the user's manual with which they were accompanied. Released in 1979, the Seventh Edition was preceded by Sixth Edition, which was the first version licensed to commercial users. Development of the Research Unix line continued with the Eighth Edition, which incorporated development from 4.1BSD, through the Tenth Edition, after which the Bell Labs researchers concentrated on developing Plan 9. V7 was the first readily portable version of Unix. As this was the era of minicompute ... [...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] |
Namespace
In computing, a namespace is a set of signs (''names'') that are used to identify and refer to objects of various kinds. A namespace ensures that all of a given set of objects have unique names so that they can be easily identified. Namespaces are commonly structured as hierarchies to allow reuse of names in different contexts. As an analogy, consider a system of naming of people where each person has a given name, as well as a family name shared with their relatives. If the first names of family members are unique only within each family, then each person can be uniquely identified by the combination of first name and family name; there is only one Jane Doe, though there may be many Janes. Within the namespace of the Doe family, just "Jane" suffices to unambiguously designate this person, while within the "global" namespace of all people, the full name must be used. Prominent examples for namespaces include file systems, which assign names to files. Some programming languages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Englewood Cliffs
Englewood Cliffs is a borough in Bergen County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 5,342, an increase of 61 (+1.2%) from the 2010 census count of 5,281, which in turn reflected a decline of 41 (-0.8%) from the 5,322 counted in the 2000 census. The borough houses the world headquarters of CNBC (NBCUniversal), the North American headquarters of South Korean conglomerate LG Corp,LG's Sustainable Flagship HOK, backed up by the as of October 17, 2012. Acces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
