ヘルプを探す：man、--help、tldr

Nobody memorizes every flag. The mark of a confident shell user is knowing how to look things up without leaving the terminal.

man opens a command’s manual page — purpose, options, and examples. It’s the authoritative reference shipped with the program itself.

Man pages open in a pager: Space/b to page, /word then n to search, and q to quit.

Read the SYNOPSIS line for usage: square brackets mean optional, ... means repeatable. Decoding it saves real time.

For a fast reminder of a command’s flags, use --help (or -h) — quicker than opening the full man page.

The manual splits into numbered sections: 1 is user commands, 5 is file formats. A name can live in several, like man 5 passwd.

Forgot the command name? apropos (or man -k) searches manual descriptions by keyword to find it.

Man pages are dense. tldr shows community-written, example-first summaries — perfect when you just want a working command.

Pick the right tool: man for the full reference, --help for a fast flag reminder, and tldr for copy-paste examples.

Shell built-ins like cd aren’t separate programs, so man cd may fail. In Bash, use help for those.

Confirm a command first: which shows its path, and type tells you if it’s a builtin, alias, or program.

You can now find answers in the shell: man for full references, --help for quick reminders, apropos to discover, tldr for examples, help for built-ins.