Summary

posix is a family of standards for UNIX-like systems. It defines consistent APIs and behavior. Goal: portability across platforms. It covers file_io, process_management, threads_pthreads, signals, permissions, and ipc_sockets. Implementations appear in linux, macos, and bsd. The posix_shell_utilities and c_libc interfaces follow these rules. Key specs come from ieee_1003 and the_open_group. Remember: write code to the posix_api to reduce porting work.