The Single UNIX Specification (SUS) is a standard for computer operating systems, [1][2] compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, and user commands.

SUS extends POSIX; LSB extends POSIX and SUS, with certain conflicts. Only SUS certified OS can be called "Unix" (because the owner of SUS, the Open Group, owns the Unix trademark); NOT all Linux distros are LSB compliant, e.g. Debian and Ubuntu are not.

The STANDARDS section that appears in many manual pages identifies various standards to which the documented interface conforms. The following list briefly describes these standards. V7 Version 7 (also known as Seventh Edition) UNIX, released by AT&T/Bell Labs in 1979. After this point, UNIX systems diverged into two main dialects: BSD and ...

Since the early 2000s, there are four major BSD operating systems– FreeBSD, NetBSD, OpenBSD and DragonFly BSD, and an increasing number of other OSs forked from these, that add or remove certain features; however, most of them remain largely compatible with their originating OS—and so are not really forks of them.

The Berkeley Software Distribution[a] (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginning in 1978.

Jan 1, 2021 · Despite being UNIX descendant, cannot be named as a UNIX because it does not comply with the SUS or POSIX. It is compatible to some degree but works needs to be done.

Jan 5, 2022 · BSD（伯克利 软件 发布版，Berkeley Software Distribution）最初是加州大学伯克利分校1979年发布的unix版本,包括了C shell,vi等功能. 由此演化成BSD的标准. AT&T1983年发布了unix系统System III,并于1989发布了System V.通过对其它厂商的使用授权使其逐渐成为很多unix功能实现的基础. POSIX先是称为 IEEE 标准，之后又被ISO采纳，因此POSIX.1为ISO/IEC 9945-1:1990. 之后陆续升级了命令与工作标准（POSIX.2）、测试方法标准（POSIX.3）、实时 …

Oct 23, 2018 · I am looking for specific details as to why isn't GNU/Linux currently SUS (Single UNIX Specification) v3 or even better SUS v4 compliant? What application APIs and user utilities does it miss or implement in a non-SUS compliant way?

Apr 27, 2022 · BSD（Berkeley Software Distribution，伯克利 软件 套件）是Unix的衍生系统，1970年代由伯克利加州大学（Uni Versity of California, Berkeley）开创。 BSD用来代表由此派生出的各种套件集合。 Linux之所以被称为类Unix操作系统 (Unix Like)，部分原因就是Linux的操作风格是介于上述二者之间，且不同厂商为了照顾不同的用户，其发行版的操作风格有存在差异。 另外要清楚，使用 TCP /IP协议的应用程序来实现网络进程间的通信的编程接口有 BSDUnix的套接 …

Sep 19, 2024 · System V和 BSD Unix操作系统在操作风格上主要分为 System V和 BSD (目前一般采用 BSD 的第4个 版本 SVR4)，前者的代表的操作系统有Solaris操作系统，在Solaris1.X之前，Solaris采用的是 BSD 风格，2.x之后才投奔 System V阵营。 后者的代表的操作系统有Free BSD。 System V它最初由AT&T开发，曾经也被称为AT&T System V. 当我们在 Linux 系统中进行进程间通信时，例如信号量，消息队列，共享内存等方式，会发现有 System V以及 POSIX 两 …