|
Write()
The write is one of the most basic Subroutine, routines provided by a Unix-like operating system kernel (operating system), kernel. It writes data from a buffer declared by the user to a given device, such as a file. This is the primary way to output data from a program by directly using a system call. The destination is identified by a file descriptor, numeric code. The String (computer science), data to be written, for instance a piece of text, is defined by a pointer (computer programming), pointer and a size, given in number of bytes. write thus takes three arguments: # The file code (file descriptor or fd). # The pointer to a data buffer, buffer where the data is stored (buf). # The number of bytes to write from the buffer (nbytes). POSIX usage The write call interface is standardized by the POSIX specification. Data is written to a file by calling the write function. The function prototype is: ssize_t write(int fildes, const void *buf, size_t nbyte); In above synta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sync (Unix)
sync is a standard system call in the Unix operating system, which commits all data from the kernel (operating system), kernel filesystem buffer (computer science), buffers to Non-volatile memory, non-volatile storage, i.e., data which has been scheduled for writing via low-level input/output, I/O system calls. Higher-level I/O layers such as C file input/output, stdio may maintain separate buffers of their own. As a function in C (programming language), C, the sync() call is typically declared as void sync(void) in . The system call is also available via a command-line interface, command line utility also called ''sync'', and similarly named functions in other languages such as Perl and Node.js (in the fs module). The related system call fsync() commits just the buffered data relating to a specified file descriptor. fdatasync() is also available to write out just the changes made to the data in the file, and not necessarily the file's related metadata. Some Unix systems run a ki ... [...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] |
Subroutine
In computer programming, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of software logic that has a well-defined interface and behavior and can be invoked multiple times. Callable units provide a powerful programming tool. The primary purpose is to allow for the decomposition of a large and/or complicated problem into chunks that have relatively low cognitive load and to assign the chunks meaningful names (unless they are anonymous). Judicious application can reduce the cost of developing and maintaining software, while increasing its quality and reliability. Callable units are present at multiple levels of abstraction in the programming environment. For example, a programmer may write a function in source code that is compiled to machine code that implements similar semantics. There is a callable unit in the source code and an associated one in the machine code, but they are different kinds of callable units with different impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Read (system Call)
In modern POSIX compliant operating systems, a program that needs to access data from a file stored in a file system uses the read system call. The file is identified by a file descriptor that is normally obtained from a previous call to open. This system call reads in data in bytes, the number of which is specified by the caller, from the file and stores then into a buffer supplied by the calling process. The read system call takes three arguments: # The file descriptor of the file. # The buffer where the read data is to be stored. # The number of bytes to be read from the file. POSIX usage The read system call interface is standardized by the POSIX specification. Data from a file is read by calling the read function: ssize_t read(int fd, void *buf, size_t count); The value returned is the number of bytes read (zero indicates end of file) and the file position is advanced by this number. It is not an error if this number is smaller than the number of bytes requested; this m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fprintf
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] |
Getchar
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] |
Fwrite
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] |
GitHub
GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug tracking system, bug tracking, software feature requests, task management, continuous integration, and wikis for every project. Headquartered in California, GitHub, Inc. has been a subsidiary of Microsoft since 2018. It is commonly used to host open source software development projects. GitHub reported having over 100 million developers and more than 420 million Repository (version control), repositories, including at least 28 million public repositories. It is the world's largest source code host Over five billion developer contributions were made to more than 500 million open source projects in 2024. About Founding The development of the GitHub platform began on October 19, 2005. The site was launched in April 2008 by Tom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Errors Encountered During Operation
An error (from the Latin , meaning 'to wander'Oxford English Dictionary, s.v. “error (n.), Etymology,” September 2023, .) is an inaccurate or incorrect action, thought, or judgement. In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behavior. Human behavior One reference differentiates between "error" and "mistake" as follows: In human behavior the norms or expectations for behavior or its consequences can be derived from the intention of the actor or from the expectations of other individuals or from a social grouping or from social norms. (See deviance.) Gaffes and faux pas can be labels for certain instances of this kind of error. More serious departures from social norms carry labels such as misbehavior and labels from the legal system, such as misdemeanor and crime. Departures from norms connected to religion can have oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typedef
typedef is a reserved keyword in the programming languages C, C++, and Objective-C. It is used to create an additional name (''alias'') for another data type, but does not create a new type, except in the obscure case of a qualified typedef of an array type where the typedef qualifiers are transferred to the array element type. As such, it is often used to simplify the syntax of declaring complex data structures consisting of struct and union types, although it is also commonly used to provide specific descriptive type names for integer data types of varying sizes. Syntax A ''typedef declaration'' follows the same syntax as declaring any other C identifier. The keyword typedef itself is a specifier which means that while it typically appears at the start of the declaration, it can also appear after the type specifiers or between two of them. In the C standard library and in POSIX specifications, the identifier for the typedef definition is often suffixed with , such as in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
