Exclamation mark

Bash builtin to substitute with a command found in history. More information: https://www.gnu.org/software/bash/manual/bash.html#Event-Designators.

• Substitute with the previous command and run it with sudo:
  sudo !!
• Substitute with a command based on its line number found with history:
  !{{number}}
• Substitute with a command that was used a specified number of lines back:
  !-{{number}}
• Substitute with the most recent command that starts with string:
  !{{string}}