man
Most commands provide a manual page or “man” page. This documentation is usually installed with the software and can be accessed with the man command.
man mkdir
This command shows the man page for mkdir.
Each man page is divided in maximum of 11 sections, some are optional:
| Section | Description |
|---|---|
| NAME | Command name and brief description |
| SYNOPSIS | Description of the command's syntax |
| DESCRIPTION | Description of the effects of the command |
| OPTIONS | Available options |
| ARGUMENTS | Available arguments |
| FILES | Auxiliary files |
| EXAMPLES | A sample of the command line |
| SEE ALSO | Cross-references to the related topics |
| DIAGNOSTICS | Warnings and Error messages |
| COPYRIGHT | Author(s) of the command |
| BUGS | Any known limitations of the command |
Man pages are organized in eight categories, numbered from 1 to 8:
| Category | Description |
|---|---|
| 1 | User command |
| 2 | System calls |
| 3 | Functions of the C library |
| 4 | Drivers and device files |
| 5 | Configuration files and file formats |
| 6 | Games |
| 7 | Miscellaneous |
| 8 | System administrator commands |
| 9 | Kernel functions (not standard) |