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GNU Find Utilities
A number of notable software packages were developed for, or are maintained by, the Free Software Foundation as part of the GNU Project. What it means to be a GNU package Summarising the situation in 2013, Richard Stallman identified nine aspects which generally apply to being a GNU package, but he noted that exceptions and flexibility are possible when there are good reasons: # The package should say that it is a GNU package. # It should be distributed via ftp.gnu.org, or another site offering access to everyone. # The package's homepage should be on the GNU website. # The developers must pay attention to making their software work well with other GNU packages. # Documentation should be in Texinfo format, or in a format easily convertible to Texinfo. # Should use GNU Guile for its extension language, but exceptions are explicitly possible in this regard. # Should not recommend any non-free program, nor refer the user to any non-free documentation or non-free software. # Use GNU t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Package (installation)
A package manager or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals with ''packages'', distributions of software and data in archive files. Packages contain metadata, such as the software's name, description of its purpose, version number, vendor, checksum (preferably a cryptographic hash function), and a list of dependencies necessary for the software to run properly. Upon installation, metadata is stored in a local package database. Package managers typically maintain a database of software dependencies and version information to prevent software mismatches and missing prerequisites. They work closely with software repositories, binary repository managers, and app stores. Package managers are designed to eliminate the need for manual installs and updates. This can be particularly useful for large enterp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chmod
In Unix and Unix-like operating systems, is the command (computing), command and system call used to change the File-system permissions, access permissions and the #Special modes, special mode flags (the setuid, ''setuid'', ''setgid'', and sticky bit, ''sticky'' flags) of file system objects (Computer file, files and Directory (computing), directories). Collectively these were originally called its modes, and the name was chosen as an abbreviation of ''change mode''. History A command first appeared in AT&T Corporation, AT&T Unix, UNIX version 1, along with the system call. As systems grew in number and types of users, access-control lists were added to many file systems in addition to these most basic modes to increase flexibility. The version of bundled in GNU coreutils was written by David MacKenzie and Jim Meyering. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of Native (computing), native Windows API, Win32 por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cksum
cksum is a command in Unix and Unix-like operating systems that generates a checksum value for a file or stream of data. The cksum command reads each file given in its arguments, or standard input if no arguments are provided, and outputs the file's 32-bit cyclic redundancy check (CRC) checksum and byte count. The CRC output by cksum is different from the CRC-32 used in zip, PNG and zlib. The cksum command can be used to verify that files transferred by unreliable means arrived intact. However, the CRC checksum calculated by the cksum command is not cryptographically secure: While it guards against ''accidental'' corruption (it is unlikely that the corrupted data will have the same checksum as the intended data), it is not difficult for an attacker to ''deliberately'' corrupt the file in a specific way that its checksum is unchanged. Unix-like systems typically include other commands for cryptographically secure checksums, such as sha256sum. The command is available as a separat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cat (Unix)
cat is a standard Unix utility that reads files sequentially, writing them to standard output. The name is derived from its function to (con)catenate files (from Latin ''catenare'', "to chain"). It has been ported to a number of operating systems. History cat was part of the early versions of Unix, e.g., Version 1, and replaced pr, a PDP-7 and Multics utility for copying a single file to the screen. It was written by Ken Thompson and Dennis Ritchie. The version of cat bundled in GNU coreutils was written by Torbjorn Granlund and Richard Stallman. The ReactOS version was written by David Welch, Semyon Novikov, and Hermès Bélusca. Over time, alternative utilities such as tac and bat also became available, bringing different new features. Usage The Single Unix Specification defines the operation of cat to read files in the sequence given in its arguments, writing their contents to the standard output in the same sequence. The specification mandates the support of one option fl ... [...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 f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mv (Unix)
mv is a Unix command that moves one or more files or directories from one place to another. If both filenames are on the same filesystem, this results in a simple file rename; otherwise the file content is copied to the new location and the old file is removed. Using mv requires the user to have write permission for the ''directories'' the file will move between. This is because mv changes the content of both directories (''i.e.'', the source and the target) involved in the move. When using the mv command on files located on the same filesystem, the file's timestamp is not updated. On UNIX implementations derived from AT&T UNIX, cp, ln and mv are implemented as a single program with hard-linked binaries. The behavior is selected from the path name argv /code>. This is a common technique by which closely related commands that have been packaged as a unit allow the user to specify the particular course of the intended action. History A command that moves a directory entry to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mknod
In Unix-like operating systems, a device file or special file is an interface to a device driver that appears in a file system as if it were an ordinary file. There are also special files in DOS, OS/2, and Windows. These special files allow an application program to interact with a device by using its device driver via standard input/output system calls. Using standard system calls simplifies many programming tasks, and leads to consistent user-space I/O mechanisms regardless of device features and functions. Overview Device files usually provide simple interfaces to standard devices (such as printers and serial ports), but can also be used to access specific unique resources on those devices, such as disk partitions. Additionally, device files are useful for accessing system resources that have no connection with any actual device, such as data sinks and random number generators. There are two general kinds of device files in Unix-like operating systems, known as ''character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mkfifo
In computing, a named pipe (also known as a FIFO for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is " unnamed" and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used. Usually a named pipe appears as a file, and generally processes attach to it for IPC. In Unix Instead of a conventional, unnamed, shell pipeline, a named pipeline makes use of the filesystem. It is explicitly created using mkfifo() or mknod(), and two separate processes can access the pipe by name — one process can open it as a reader, and the other as a writer. For example, one can create a pipe and set up gzip to compress things piped to it: mkfifo my_pipe gzip -9 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mkdir
The mkdir (make directory) command in the Unix, DOS, DR FlexOS, IBM OS/2, Microsoft Windows, and ReactOS operating systems is used to make a new directory. It is also available in the EFI shell and in the PHP scripting language. In DOS, OS/2, Windows and ReactOS, the command is often abbreviated to md. The command is analogous to the Stratus OpenVOS create_dir command. MetaComCo TRIPOS and AmigaDOS provide a similar MakeDir command to create new directories. The numerical computing environments MATLAB and GNU Octave include an mkdir function with similar functionality. History In early versions of Unix ( 4.1BSD and early versions of System V), this command had to be setuid root as the kernel did not have an mkdir syscall. Instead, it made the directory with mknod and linked in the . and .. directory entries manually. The command is available in MS-DOS versions 2 and later. Digital Research DR DOS 6.0 and Datalight ROM-DOS also include an implementation of the and comma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ln (Unix)
The command is a standard Unix command utility used to create a hard link or a symbolic link (symlink) to an existing file or directory. The use of a hard link allows multiple filenames to be associated with the same file since a hard link points to the inode of a given file, the data of which is stored on disk. On the other hand, symbolic links are special files that refer to other files by name. The command by default creates hard links, and when called with the command line parameter creates symbolic links. Most operating systems prevent hard links to directories from being created since such a capability could disrupt the structure of a file system and interfere with the operation of other utilities. The command can however be used to create symbolic links to non-existent files. History ln appeared in Issue 2 of the X/Open Portability Guidelines. The version of bundled in GNU coreutils was written by Mike Parker and David MacKenzie. The command is available as a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Dir (Unix)
LS may refer to: Businesses * LS Group, a Korean company * Jet2.com (IATA code: LS), a British airline Latin * Lewis and Short (abbr. "L&S"), authors of the 1879 work ''A Latin Dictionary'' * Lectori Salutem (L.S.), Latin for 'Greetings Reader' and used as opening words to a letter * ''locus sigilli'', Latin for 'place of the seal', used in notarized and legal documents; see: Seal (contract law) Organizations * Liberal Party of Croatia ( hr, Liberalna stranka or LS), a Croatian political party active from 1998–2006 * Lincoln-Sudbury Regional High School, Massachusetts, US * Lok Sabha, the lower house of the Parliament of India * Loyola Schools, the college unit of the Ateneo de Manila University in Quezon City, Philippines Places * Lesotho (ISO 3166-1 country code: LS), a country in southern Africa * LS postcode area, UK, covering Leeds * County Laois, Ireland Science, technology, and mathematics Astronomy * Light-second (ls), a unit of length in astronomy eq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
