Sudosudo (suːduː or ˈsuːdoː) is a program for Unix-like computer operating systems that enables users to run programs with the security privileges of another user, by default the superuser. It originally stood for "superuser do", as that was all it did, and it is its most common usage; however, the official Sudo project page lists it as "su 'do'". The current Linux manual pages for su define it as "substitute user", making the correct meaning of sudo "substitute user, do", because sudo can run a command as other users as well.
Privilege separationIn computer programming and computer security, privilege separation is one software-based technique for implementing the principle of least privilege. With privilege separation, a program is divided into parts which are limited to the specific privileges they require in order to perform a specific task. This is used to mitigate the potential damage of a computer security vulnerability. A common method to implement privilege separation is to have a computer program fork into two processes.
File lockingFile locking is a mechanism that restricts access to a , or to a region of a file, by allowing only one user or process to modify or delete it at a specific time and to prevent reading of the file while it's being modified or deleted. Systems implement locking to prevent the classic interceding update scenario, which is a typical example of a race condition, by enforcing the serialization of update processes to any given file.
Giant lockIn operating systems, a giant lock, also known as a big-lock or kernel-lock, is a lock that may be used in the kernel to provide concurrency control required by symmetric multiprocessing (SMP) systems. A giant lock is a solitary global lock that is held whenever a thread enters kernel space and released when the thread returns to user space; a system call is the archetypal example. In this model, threads in user space can run concurrently on any available processors or processor cores, but no more than one thread can run in kernel space; any other threads that try to enter kernel space are forced to wait.
Tux (mascot)Tux is a penguin character and the official brand character of the Linux kernel. Originally created as an entry to a Linux logo competition, Tux is the most commonly used icon for Linux, although different Linux distributions depict Tux in various styles. The character is used in many other Linux programs and as a general symbol of Linux. The concept of the Linux brand character being a penguin came from Linus Torvalds, the creator of Linux.
HackathonA hackathon (also known as a hack day, hackfest, datathon or codefest; a portmanteau of hacking and marathon) is an event where people engage in rapid and collaborative engineering over a relatively short period of time such as 24 or 48 hours. They are often run using agile software development practices, such as sprint-like design wherein computer programmers and others involved in software development, including graphic designers, interface designers, product managers, project managers, domain experts, and others collaborate intensively on engineering projects, such as software engineering.
NetBSDNetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. Its source code is publicly available and permissively licensed.
XFree86XFree86 is an implementation of the X Window System. It was originally written for Unix-like operating systems on IBM PC compatibles and was available for many other operating systems and platforms. It is free and open source software under the XFree86 License version 1.1. It was developed by the XFree86 Project, Inc. The lead developer was David Dawes. The last released version was 4.8.0, released December 2008. The last XFree86 CVS commit was made on May 18, 2009; the project was confirmed dormant in December 2011.
PF (firewall)PF (Packet Filter, also written pf) is a BSD licensed stateful packet filter, a central piece of software for firewalling. It is comparable to netfilter (iptables), ipfw, and ipfilter. PF was developed for OpenBSD, but has been ported to many other operating systems. PF was originally designed as replacement for Darren Reed's IPFilter, from which it derives much of its rule syntax. IPFilter was removed from OpenBSD's CVS tree on 30 May 2001 due to OpenBSD developers' concerns with its license.
Ports collectionPorts collections (or ports trees, or just ports) are the sets of s and patches provided by the BSD-based operating systems, FreeBSD, NetBSD, and OpenBSD, as a simple method of installing software or creating binary packages. They are usually the base of a package management system, with ports handling package creation and additional tools managing package removal, upgrade, and other tasks. In addition to the BSDs, a few Linux distributions have implemented similar infrastructure, including Gentoo's Portage, Arch's Arch Build System (ABS), CRUX's Ports and Void Linux's Templates.
