An open information system - as defined by the IEEE POSIX 1003.0 Committee, an open information system is a system that implements open specifications for interfaces, services (environment services) and supported data formats sufficient to enable a properly developed application software to be tolerated over a wide range of systems with minimal modifications, to interact with other applications on the local and remote systems, and interact with the user telyami in a style that makes it easier to transition users from system to system.
An open specification , as defined by POSIX, is an open specification that is supported by an open, transparent, conciliatory process aimed at adapting the new technology to its application, and which is consistent with standards.
Open System Properties
The main properties of open systems:
- Extensibility
- Scalability
- Portability of applications, data and personnel.
- Interoperability of applications and systems
- Ability to integrate
- High availability
Composition
The standard consists of four main sections:
- Basic definitions - a list of basic definitions and conventions used in the specifications, and a list of C language header files that must be provided by the appropriate standard system.
- Shell and utilities - description of utilities and shell command sh, regex standards.
- System interfaces - a list of C system calls.
- Rationale - An explanation of the principles used in the standard.