OPS435 Lecture 3 - Bash

Linux processes

• ps
• kill
• top

Using BASH History

• history command
•  ! command

User-define variables

• Setting
• Reading

Quoting & escaping

• Single quotes
• Double quotes
• Back quotes
• Escaping special characters

Shell Expansions

• Pathname expansion examples
  • ls abc*
  • echo abc?
  • LANG=C;echo [A-Z]*
• brace expansion examples
  • seq command
  • echo {1..5}
  • echo {a..m}
  • touch file{1,2,3,4}
  • touch file{1..4}
  • touch file{2,4,6,8}
  • mkdir ops435/{labs,notes}
• Tilde expansion examples
  • echo ~

• Command substitution examples
  • echo $(date)
  • echo `date`

• Arithmetic expansion examples
  • echo $((2 + 2))
  • x=$((5/2))