POSIX is an acronym for Portable Operating System Interface, a family of standards specified by the IEEE for maintaining compatibility between operating systems.
POSIX is a family of standards that specify the behavior of Unix-like operating systems.
These standards define:
- A standard operating system interface and environment.
- A programming API for the C programming language.
- The behavior of a command interpreter (or shell).
- The behavior of common utility programs invocable from the shell.
The current set of POSIX standards is available online.