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Du (Unix)
du (abbreviated from ''disk usage'') is a standard Unix program used to estimate file space usage—space used under a particular directory or files on a file system. A Windows commandline version of this program is part of Sysinternals suite by Mark Russinovich. History The du utility first appeared in version 1 of AT&T UNIX. The version of du bundled in GNU coreutils was written by Torbjorn Granlund, David MacKenzie, Paul Eggert, and Jim Meyering. The command is also available for FreeDOS. Specification By default, the Single UNIX Specification (SUS) specifies that du is to display the file space allocated to each file and directory contained in the current directory. Links will be displayed as the size of the link file, not what is being linked to; the size of the content of directories is displayed, as expected. As du reports allocation space and not absolute file space, the amount of space on a file system shown by du may vary from that shown by df if files have been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennis Ritchie
Dennis MacAlistair Ritchie (September 9, 1941 – October 12, 2011) was an American computer scientist. He is most well-known for creating the C (programming language), C programming language and, with long-time colleague Ken Thompson, the Unix operating system and B (programming language), B programming language. Ritchie and Thompson were awarded the Turing Award from the Association for Computing Machinery, ACM in 1983, the IEEE Richard W. Hamming Medal, Hamming Medal from the Institute of Electrical and Electronics Engineers, IEEE in 1990 and the National Medal of Technology from Bill Clinton, President Bill Clinton in 1999. Ritchie was the head of Lucent, Lucent Technologies System Software Research Department when he retired in 2007. He was the "R" in The C Programming Language, K&R C, and commonly known by his User (computing), username dmr. Personal life and career Dennis Ritchie was born in Bronxville, New York. His father was Alistair E. Ritchie, a longtime Bell Labs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directory (computing)
In computing, a directory is a file system cataloging structure which contains references to other computer files, and possibly other directories. On many computers, directories are known as folders, or drawers, analogous to a workbench or the traditional office filing cabinet. The name derives from books like a telephone directory that lists the phone numbers of all the people living in a certain area. Files are organized by storing related files in the same directory. In a hierarchical file system (that is, one in which files and directories are organized in a manner that resembles a tree), a directory contained inside another directory is called a subdirectory. The terms parent and child are often used to describe the relationship between a subdirectory and the directory in which it is cataloged, the latter being the parent. The top-most directory in such a filesystem, which does not have a parent of its own, is called the root directory. Overview Historically, and eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. The International System of Units (SI) defines the prefix '' kilo'' as 1000 (103); per this definition, one kilobyte is 1000 bytes.International Standard IEC 80000-13 Quantities and Units – Part 13: Information science and technology, International Electrotechnical Commission (2008). The internationally recommended unit symbol for the kilobyte is kB. In some areas of information technology, particularly in reference to solid-state memory capacity, ''kilobyte'' instead typically refers to 1024 (210) bytes. This arises from the prevalence of sizes that are powers of two in modern digital memory architectures, coupled with the accident that 210 differs from 103 by less than 2.5%. A kibibyte is defined by Clause 4 of IEC 80000-13 as 1024 bytes. Definitions and usage Base 10 (1000 bytes) In the International System of Units (SI) the prefix '' kilo'' means 1000 (103); therefore, one kilobyte is 1000 bytes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megabyte
The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities. In the computer and information technology fields, other definitions have been used that arose for historical reasons of convenience. A common usage has been to designate one megabyte as (220 B), a quantity that conveniently expresses the binary architecture of digital computer memory. The standards bodies have deprecated this usage of the megabyte in favor of a new set of binary prefixes, in which this quantity is designated by the unit mebibyte (MiB). Definitions The unit megabyte is commonly used for 10002 (one million) bytes or 10242 bytes. The interpretation of using base 1024 originated as technical jargon for the byte multiples t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SI Prefix
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. Established and maintained by the General Conference on Weights and Measures (CGPM), it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), mole (mol, amount of substance), and candela (cd, luminous intensity). The system can accommodate coherent units for an unlimited number of additional quantities. These are called coherent derived units, which can always be represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as The Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The first bit is number 0, making the eighth bit number 7. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rm (Unix)
rm (short for ''remove'') is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the del command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell. Overview The rm command removes references to objects from the filesystem using the unlink system call, where those objects might have had multiple references (for example, a file with two different names), and the objects themselves are discarded only when all references have been removed and no programs still have open handles to the objects. This allows for scenarios where a program can open a file, immediately remove it from the filesystem, and then use it for temporary space, knowing that the file's space will be reclaimed after the program exits, even if it exits by crashing. The command generally does not destroy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Df (Unix)
(abbreviation for ''disk free'') is a standard Unix command used to display the amount of available disk space for file systems on which the invoking user has appropriate read access. is typically implemented using the statfs or statvfs system calls. History for Unix-like systems is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX and the Single Unix Specification. It first appeared in Version 1 AT&T Unix. The version of bundled in GNU coreutils was written by Torbjorn Granlund, David MacKenzie, and Paul Eggert. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. Usage The Single UNIX Specification specifications for are: df k -tdel ile... ; :Use 1024-byte units, instead of the default 512-byte units, when writing space figures. ; :Use a standard, portable, output format ; :Display in more easily hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Unix
The history of Unix dates back to the mid-1960s, when the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric were jointly developing an experimental time-sharing operating system called Multics for the GE-645 mainframe. Multics introduced many innovations, but also had many problems. Bell Labs, frustrated by the size and complexity of Multics but not its aims, slowly pulled out of the project. Their last researchers to leave Multics – among them Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna – decided to redo the work, but on a much smaller scale. APDF/ref> In 1979, Ritchie described the group's vision for Unix: 1960s In the late 1960s, Bell Labs was involved in a project with MIT and General Electric to develop a time-sharing system, called Multiplexed Information and Computing Service (Multics), allowing multiple users to access a mainframe simultaneously. Dissatisfied with the project's progress, Bell Labs management ultimately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark Russinovich
Mark Eugene Russinovich (born December 22, 1966) is a Spanish-born American software engineer and author who serves as CTO of Microsoft Azure. He was a cofounder of software producers Winternals before it was acquired by Microsoft in 2006. Early life and education Russinovich was born in Salamanca, Spain and was raised in Birmingham, Alabama, United States, until he was 15, when he moved with his family to Pittsburgh, Pennsylvania. His father was a radiologist and his mother was a business administrator of his father's radiology practice in Pittsburgh. Russinovich is of Croatian descent. He was introduced to computers when his friend's father got an Apple II in the 1970s. He was able to reverse engineer its ROM and write programs for it. At age 15, he bought himself his first computer, a Texas Instruments TI99/4A. About six months later his parents bought him an Apple II+ from his local high school when it upgraded the computer labs to Apple IIes. He also wrote magazine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sysinternals
Windows Sysinternals is a website that offers technical resources and utilities to manage, diagnose, troubleshoot, and monitor a Microsoft Windows environment. Originally, the Sysinternals website (formerly known as ntinternals) was created in 1996 and was operated by the company Winternals Software LP, which was located in Austin, Texas. It was started by software developers Bryce Cogswell and Mark Russinovich. Microsoft acquired Winternals and its assets on July 18, 2006. The website featured several freeware tools to administer and monitor computers running Microsoft Windows. The software can now be found at Microsoft. The company also sold data recovery utilities and professional editions of their freeware tools. Winternals Software LP Winternals Software LP was founded by Bryce Cogswell and Mark Russinovich, who sparked the 2005 Sony BMG CD copy protection scandal in an October 2005 posting to the Sysinternals blog. On July 18, 2006, Microsoft Corporation acquired the comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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