Can you explain what is meant by POSIX standards in UNIX operating systems?

POSIX (Portable Operating System Interface) is a set of standards developed to ensure compatibility and portability of software across different UNIX family operating systems. POSIX standards define interfaces for system calls, command-line utilities, file formats, and other aspects so that programs written for one POSIX-compliant system can run on others with minimal modifications.

For example, POSIX describes things like:

• Process management (fork, exec)
• File and directory management
• Signals
• Threads and synchronization

Thus, POSIX serves as the foundation for standardizing UNIX-like systems and facilitates application portability between them.