Basics

    1. touch file_{01..100}; ls # file01 file02 .. file100

      use >:

      • is stdout
      • 2 is sterr
      • & is stdout and sterr

      grep

      To enable it all the time use:
      export GREP_OPTIONS='--color=auto'

      This will print only the 12th word on every sentence:

      1. grep -i break-in auth.log | awk {'print $12'}

      Another useful command: