Understanding POSIX

About POSIX

• General

  • Portable Operating System Interface
  • Since 1988~
  • Started with the idea of unifying at least a minimal area since different operating systems use different APIs, causing development difficulties
  • Spec: http://get.posixcertified.ieee.org/
  • Versions
    • POSIX.1 (IEEE 1003.1-1988): core services
    • POSIX.2 (IEEE 1003.2-1992): shell & utility
    • POSIX.1b (IEEE 1003.1b-1993): realtime related
    • POSIX.1c (IEEE 1003.1c-1995): Thread related
  • Released up to POSIX.1 - 2017
    • Process creation & control, signals, file & directory operations, pipes, C library, I/O port interface and control, process triggers

• POSIX PSE51-compliant API

  • Defined in IEEE 1003.13
  • POSIX Realtime and Embedded Application Support (AEP)
  • PSE51-Minimal Realtime System Profile: small embedded systems, no MMU, no Disk, no terminal