2 - Getting Help

Concept

• --help command is quick start guide.

• man command is encyclopedia.

Function 1     Manual of command

1. man [Command]  

   • Exp: man passwd

2. Each command contains several sections.

3. Check all manual sections

   • whatis [Command]  

   • Exp: whatis passwd

4. Direct to specific section

   • man [Section] [Command]  

   • man 5 passwd

5. Flip to next section

   • man -a [Command]  

   • Exp: man -a passwd

Function 2    Search engine of command

If you forgot some command, can insert keywords to search all commands that contains keywords

• man -k [Keyword]  

  • Exp: man -k passwd

• man -k [1st Priority Keyword]  | grep [2nd Priority Keyword] 

  • Find add user function, Exp: man -k passwd | grep add