Number in man page titles e.g. sleep(3)

4 hours ago

Man pages are organized into sections indicated by numbers, each representing different types of documentation.
Section 1 covers executable programs or shell commands.
Section 2 covers system calls provided by the kernel.
Section 3 covers library calls within program libraries.
Letters can be suffixes to numbers, like 'p' for POSIX man pages (e.g., free(3p)) or 'x' for X documentation (e.g., ncurses(3x)).
The author learned about these distinctions after a code review comment corrected the use of 'man 2 basename' to 'man 3 basename'.

Hasty Briefsbeta