Unix Command Basic

Command Fundamentals

1. general form : command options arguments
   1. option: change the manner of operation of a command
      1. start  with – or —
   2. argument: object of command
2. command is a build program / built-in operation

Help with command

1. man command
2. apropos
3. whatis
4. info command
5. khelpcenter

Program Execution Environment

• HOME:your home directory
• PATH: directories that are automatically searched
  • control where to look for commands
• TERM your output (display) device
• more…
• env / printenv / set : print all environment variable
• export EnvVar=Value (change value of environment variable)(persist)

 

Useful Directories

• /bin                      “minimal set” commands
• /usr/bin               most user commands
• /usr/local/bin    local versions of commands

 

Locate a command

• which/ whereis

 

History Buffer: record of the last command

• history command: print 1000 command used before
• !!: repeat the last command used
• !number: repeat last number
• !string: repeat last string

Command/Filename Completion

• character + TAB to get all possibility of completion of the command
• ^X/ possible file name
• ^X! possible command
• use FIGNORE shell variable to check additionally function

Variable SHELLOPTS shows a list of enabled shell options

Control terminal setting by stty command

Set shortcut of command: alias Var  =”command”

• see all alias by alias
• remove by unalias