If you are a Windows user, press the keys Windows-R simultaneously to open the Run window, then you can use the help command to get some information on any command, e.g., help taskkill, help dir, or help date.
The forward slash (/) is used to execute a command option or perform a switch, the question mark (?) is for the help switch in particular, e.g., ipconfig /?, systeminfo /? or attrib /?
Other ways to get some help and find solutions to problems in Windows are: Microsoft Support. The Get Help app: Just type Get Help on the taskbar and then type your doubt or problem in the search box. Use Windows Troubleshooters: Settings, System, Troubleshoot, Other troubleshooters.
If you are a macOS or GNU/Linux user:
Use the command options -h or -help.
[[email protected] cwd]$ paccache -h
A flexible pacman cache cleaning utility.
Usage: paccache [options][targets...] Operations:
-d, --dryrun perform a dry run, only finding candidate packages.
-m, --move move candidate packages to "dir".
-r, --remove remove candidate packages.
--min-atime --min-mtime than the time given, even if this means keeping more
than specified through the '--keep' option. Accepts
arguments according to 'info "Date input formats"',
e.g. '30 days ago'.
-a, --arch scan for"arch"(default: all architectures).
Sometimes, you don’t know the exact name of a command, then you can make use of tab completion. Just type the beginning of the command and then press tab.
If you want a quick way of knowing the purpose and use of a command without going through the whole manual, whatis displays one-line manual page descriptions:
[[email protected] cwd]$ whatis ps
ps (1) - report a snapshot of the current processes.
[[email protected] cwd]$ whatis surfraw
surfraw (1) - a fast unix command line interface to WWW services
The command man is the general help. Some examples are: man ps, man fdisk.
When you are reading a man page, remember: / search_string, find matches to “search_string”; n go to the next match; and type q to quit or exit.
tldr (aka “Too Long Didn’t Read") are simplified and community-driven man pages with practical examples. Installation: brew install tldr (macOS), sudo pacman -S tldr (Arch), sudo apt install tldr (Ubuntu). Update offline cache of tldr pages: tldr ‐‐update. Use: tldr grep.
apropos helps you when you don’t remember the exact command but a keyword related to it, e.g. apropos firewall.
And last, but not least, cheat allows you to create, edit, and view interactive cheatsheets on the command-line.
Installation: sudo snap install cheat
Use: cheat tail
The first time you launch it, it will ask you two questions: A config file was not found. Would you like to create one now? Y Would you like to download the community cheatsheets? Y.
To edit a cheatsheet: cheat -e tail.