POSIX.1-2008 defines a standard operating system interface and environment, including a command interpreter (or “shell”), and common utility programs to support applications portability at the source code level. It is intended to be used by both application developers and system implementors.
IEEE 1003.1, 2016 Edition
$446.00
IEEE Standard for Information Technology–Portable Operating System Interface (POSIX(TM)) Base Specifications, Issue 7