POSIX是什么?我读过维基百科上的文章，每次遇到这个词我都会去读。事实上，我从来没有真正理解它是什么。
有没有人可以通过解释“POSIX的需求”来解释给我听?
当前回答
POSIX为操作系统或程序定义了一组标准。 目标是编写与类unix系统兼容的新软件。
例如，在Linux上运行的程序也可以在其他类unix系统上编译和运行，如Solaris、HP-UX和AIX等。
最流行的例子是GNU Bash，它100%符合POSIX和gawk实用程序。
其他回答
该标准为类unix操作系统提供了一个公共基础。它指定了shell应该如何工作，期望从ls和grep等命令中得到什么，以及C作者期望可用的一些C库。
例如，这里详细地指定了命令行用户用来将命令串在一起的管道，这意味着C的popen(管道打开)函数是posix标准的，而不是ISO C标准的。
POSIX为操作系统或程序定义了一组标准。 目标是编写与类unix系统兼容的新软件。
例如，在Linux上运行的程序也可以在其他类unix系统上编译和运行，如Solaris、HP-UX和AIX等。
最流行的例子是GNU Bash，它100%符合POSIX和gawk实用程序。
In 1985, individuals from companies throughout the computer industry joined together to develop the POSIX (Portable Operating System Interface for Computer Environments) standard, which is based largely on the UNIX System V Interface Definition (SVID) and other earlier standardization efforts. These efforts were spurred by the U.S. government, which needed a standard computing environment to minimize its training and procurement costs. Released in 1988, POSIX is a group of IEEE standards that define the API, shell, and utility interfaces for an operating system. Although aimed at UNIX-like systems, the standards can apply to any compatible operating system. Now that these stan- dards have gained acceptance, software developers are able to develop applications that run on all conforming versions of UNIX, Linux, and other operating systems.
摘自《Linux实用指南》
POSIX是一种操作系统标准，旨在使编写跨平台软件变得更容易。这在Unix世界中是一件特别重要的事情。
Posix governs interoperability, portability, and in other areas such as the usage and mechanism of fork, permissions and filesystem standards such as /etc, /var, /usr and so on . Hence, when developers write a program under a Posix compliant system such as for example Linux, it is generally, not always, guaranteed to run on another posix compliant system such as IBM's AIX system or other commercial variants of Unix. Posix is a good thing to have as such it eases the software development for maximum portability which it strives for. Hope this answer makes sense.
感谢Jed Smith和Tinkertim指出我的错误——我的错!!：(
