The Linux man-pages project -online resources / manual pages - sections / etc

Look here to find these beauties:   https://www.kernel.org/doc/man-pages/

The Linux man-pages project documents the Linux kernel and C library interfaces that are employed by user-space programs. With respect to the C library, the primary focus is the GNUC library (glibc), although, where known, documentation of variations on other C libraries available for Linux is also included.

The man-pages project provides manual pages in the following sections:

• 1: User command; man-pages includes a very few Section 1 pages that document programs supplied by the GNU C library.
• 2: System calls documents the system calls provided by the Linux kernel.
• 3: Library functions documents the functions provided by the standard C library.
• 4: Devices documents details of various devices, most of which reside in /dev.
• 5: Files describes various file formats, and includes proc(5), which documents the /proc file system.
• 7: Overviews, conventions, and miscellaneous.
• 8: Superuser and system administration command; man-pages includes a very few Section 8 pages, mainly documenting programs supplied by the GNU C library.