Portable Operating System Interface (POSIX)

The POSIX standard has the main task of maintaining compatibility between different OSs. Therefore, POSIX is frequently used by both standard application software developers and system programmers. Nowadays, it can be found not only on Unix-like OSs, but in Windows environments as well – for example, Cygwin, MinGW, and Windows Subsystem for Linux (WSL). POSIX defines both the system- and the user-level APIs with one remark: using POSIX, the programmer doesn’t need to distinguish between system calls and library functions.

The POSIX API is frequently used in the C programming language. Thus, it is compilable with C++. Additional functions are provided to the system call interface in a few important areas of system programming: file operations, memory management, process and thread control, networking and communications, and regular expressions – as you can see, it pretty much covers everything that the already existing...