Unix Section 2 Manual Page: System Calls (.2)
A 2 file extension refers to a Unix manual page (man page) that documents a specific system call. These files are part of the Section 2 of the Unix manual, which is dedicated to system calls. Each 2 file is named after the system call it describes, such as "link.2" for the "link" system call. These files are intended to be viewed using the "man" utility in Unix-based systems. Historically, they have been a fundamental part of Unix documentation, providing detailed information on how to use system calls, their return values, possible errors, and related manual pages.