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Rm (Unix)
rm, short for remove, is a shell command for removing files (which includes special files such as directories) from the file system. The command may not actually delete a file (release its storage for reuse) since it only unlinks it removes a hard link to a file via the unlink() system call. If a file has multiple links and less than all are removed, then the file remains in the file system; accessible via its other links. When a file's only link is removed, then the file is deleted releasing its storage space for other use. Generally, a deleted file's former storage space still contains the file's data until it is overwritten with another file's content. The data is not accessible via normal file operations but can be recovered via specialized tools. Since this is considered a security risk in some contexts, a hardened version of may wipe the file's storage area when the file is deleted. Commands such as shred and srm specifically provide data wiping. Since rm does no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ken Thompson
Kenneth Lane Thompson (born February 4, 1943) is an American pioneer of computer science. Thompson worked at Bell Labs for most of his career where he designed and implemented the original Unix operating system. He also invented the B (programming language), B programming language, the direct predecessor to the C (programming language), C language, and was one of the creators and early developers of the Plan 9 from Bell Labs, Plan 9 operating system. Since 2006, Thompson has worked at Google, where he co-developed the Go (programming language), Go language. A recipient of the Turing award, he is considered one of the greatest computer programmers of all time. Other notable contributions included his work on regular expressions and early computer text editors QED (text editor), QED and ed (text editor), ed, the definition of the UTF-8 encoding, and his work on computer chess that included the creation of endgame tablebases and the chess machine Belle (chess machine), Belle. He won ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT License
The MIT License is a permissive software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts very few restrictions on reuse and therefore has high license compatibility. Unlike copyleft software licenses, the MIT License also permits reuse within proprietary software, provided that all copies of the software or its substantial portions include a copy of the terms of the MIT License and also a copyright notice. In 2015, the MIT License was the most popular software license on GitHub, and was still the most popular in 2025. Notable projects that use the MIT License include the X Window System, Ruby on Rails, Node.js, Lua (programming language), Lua, jQuery, .NET, Angular (web framework), Angular, and React (JavaScript library), React. License terms The MIT License has the identifier MIT in the SPDX License List. It is also known as the "#Ambiguity and variants, Expat License". It has the following terms: Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undelete
Undeletion is a feature for restoring computer files which have been removed from a file system by file deletion. Deleted data can be recovered on many file systems, but not all file systems provide an undeletion feature. Recovering data without an undeletion facility is usually called data recovery, rather than undeletion. Undeletion can both help prevent users from accidentally losing data, or can pose a computer security risk, since users may not be aware that deleted files remain accessible. Support Not all file systems or operating systems support undeletion. Undeletion is possible on all FAT file systems, with undeletion utilities provided since MS-DOS 5.0 and DR DOS 6.0 in 1991. It is not supported by most modern UNIX file systems, though AdvFS is a notable exception. The ext2 file system has an add-on program called e2undel which allows file undeletion. The similar ext3 file system does not officially support undeletion, but utilities like ext4magic, extundelete, Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recycle Bin (computing)
A recycling bin (or recycle bin) is a Waste receptacle, container used to hold Recycling, recyclables before they are taken to Materials recovery facility, recycling centers. Recycling bins exist in various sizes for use inside and outside of homes, offices, and large public facilities. Separate containers are often provided for paper, tin or aluminum Tin can, cans, and glass or plastic bottles, with some bins allowing for commingled, mixed recycling of various materials. Bins are sometimes in different colors so that the user can differentiate between the types of materials specified for each bin. While there is no universal standard color for recycling, the color blue is commonly used to indicate recycling in public settings. Other regions also use the color green to differentiate between types of recyclable materials. Recycling bins, cans, or wheeled carts (''toters'') are common elements of municipal kerbside collection programs, which frequently distribute eye-catching bins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Srm (Unix)
srm (or Secure Remove) is a command line utility for Unix-like computer systems for secure file deletion. srm removes each specified file by overwriting, renaming, and truncating it before unlinking. This prevents other people from undeleting or recovering any information about the file from the command line. Platform-specific behaviours and bugs Filesystems with hard links Attempting to secure delete a file with multiple hard links results in a warning from srm stating that the current access path has been unlinked, but the data itself was not overwritten or truncated. This is an undocumented feature of srm 1.2.8 on Mac OS X 10.9, and is erroneously documented in 1.2.11 as a behaviour activated by the OpenBSD rm-compatible option -P. However, in both the OS X and SourceForge srm implementations, the behaviour of unlinking but not overwriting multi-linked files is always active, as long as the platform reports hard links. srm 1.2.8 on Mac OS X 10.9 has a -n option, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shred (Unix)
is a command on Unix-like operating systems that can be used to securely delete files and devices so that it is extremely difficult to recover them, even with specialized hardware and technology; assuming recovery is possible at all, which is not always the case. It is a part of GNU Core Utilities. Being based on the Gutmann method paper, it suffers from the same criticisms and possible shortcomings. Background For efficiency, the process of erasing a file from storage using the command usually only erases the file's file-system entry while keeping the content of the file intact. This frequently allows commonly available software to recover the "erased" file's data. If the file data is stored on magnetic media such as a HDD, even if the file is overwritten, residual magnetic fields may allow data recovery using specialist hardware equipment (this claim is disputed; see ). To prevent this, overwrites the contents of a file multiple times, using patterns chosen to maximiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Security
Application security (short AppSec) includes all tasks that introduce a secure software development life cycle to development teams. Its final goal is to improve security practices and, through that, to find, fix and preferably prevent security issues within applications. It encompasses the whole application life cycle from requirements analysis, design, implementation, verification as well as maintenance. Web application security is a branch of information security that deals specifically with the security of website, websites, web application, web applications, and web service, web services. At a high level, web application security draws on the principles of application security but applies them specifically to the internet and World Wide Web, web systems. The application security also concentrates on Mobile app, mobile apps and their security which includes iOS and Android Applications Web Application Security Tools are specialized tools for working with HTTP traffic, e.g., We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Call
In computing, a system call (syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. This may include hardware-related services (for example, accessing a hard disk drive or accessing the device's camera), creation and execution of new processes, and communication with integral kernel services such as process scheduling. System calls provide an essential interface between a process and the operating system. In most systems, system calls can only be made from userspace processes, while in some systems, OS/360 and successors for example, privileged system code also issues system calls. For embedded systems, system calls typically do not change the privilege mode of the CPU. Privileges The architecture of most modern processors, with the exception of some embedded systems, involves a security model. For example, the '' rings'' model specifies multiple privilege levels under which software may be e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unlink (Unix)
In Unix-like operating systems, unlink is a system call and a command line utility to delete files. The program directly interfaces the system call, which removes the file name and (but not on GNU systems) directories like rm and rmdir. If the file name was the last hard link to the file, the file itself is deleted as soon as no program has it open. Unlike the rm utility, the unlink utility only accepts one argument, which can be desirable to guard against accidental multi-deletions. It also appears in the PHP, Node.js, R, Perl and Python standard libraries in the form of the ''unlink()'' built-in function. Like the Unix utility, it is also used to delete files. Examples To delete a file named ''foo'', one could type: % unlink foo In PHP, one could use the following function to do the same: unlink("foo"); The Perl syntax is identical to the PHP syntax, save for the parentheses: unlink "foo"; In Node.js it is almost the same as the others: fs.unlink("foo", callb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Link
In computing, a hard link is a directory entry (in a Directory (computing), directory-based file system) that associates a name with a Computer file, file. Thus, each file must have at least one hard link. Creating additional hard links for a file makes the contents of that file accessible via additional Path (computing), paths (i.e., via different names or in different directories). This causes an Aliasing (computing), alias effect: a process can open the file by any one of its paths and change its content. By contrast, a soft link or File shortcut, “shortcut” to a file is not a direct link to the data itself, but rather a reference to a hard link or another soft link. Every directory is itself a special file on many systems, containing a list of file names instead of other data. Hence, multiple hard links to directories are possible, which could create a circular directory structure, rather than a branching structure like a Tree structure, tree. For that reason, some file sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directory (computing)
In computing, a directory is a file system cataloging structure that contains references to other computer files, and possibly other directories. On many computers, directories are known as folders or drawers, analogy, 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 structure, 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. The freedesktop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
