Unix Section 3 Manual Page

Man pages contain documentation for system-level features of a Unix-based operating system. The pages are typically grouped into eight sections, each of which contains documentation for a subset of system information.

The third man page section describes library functions that can be used in the operating system . In particular, these sections describe C library functions.

For example, the file attr_get.3 contains documentation related to the attr_get and attr_getf library functions. It includes a quick synopsis of how to use the functions, a detailed description of the functions, and additional information.

NOTE: Other sections' Unix man pages use the .1 , .2 , .4 , .5 , .6 , .7 , and .8 extensions. Man pages are also commonly compressed into .GZ files (which may use the .gz.# extension).

In Unix-like OSes, you can open a 3 file by calling the man utility using the name of the file. For example, to open attr_get.3 , enter man attr_get(3) .

Since 3 files are plain text files, you can also open them in any text editor, such as Vim (Linux, Mac), Microsoft Notepad (Windows), and Apple TextEdit (Mac).

Programs that open 3 files

Updated: February 24, 2022