oplaTech About Teaching Archive
Oplatek's external memory

Week 13, Intro to Unix lab 2016

Content

  • questions
  • awk - reading output of pipe
    • mycommand = "seq 10"
    • getline mycommand - read one row of stdout of mycommand to $0
    • ! ( mycommand | getline ) - test if reading failed (EOF)
  • collaborative test - hackathon
    • task - simplified postfix calculator
      • with four variables:
        • last - read only
        • X, Y, Z - read and write
      • with four operations
        • + x / - =' - the last one is assign, not equal
      • examples
        • x prints 0 - variables are initialized to 0
        • 3 4 + prints 7
        • 1 2 + 3 * prints 9
        • 1 2 3 + * fails and does not print 5 - simplified postfix you need to write 2 3 + 1 *
        • 3 last + prints 6 - last is initialized at the first argument at start
        • 3 last + last + prints 12
        • X 3 = prints 3 and assing x to 3
        • X 3 = X x assing x to 3 and prints 9
    • how to divide work to pairs
      • define interfaces
  • Recommended reading - Shell v příkladech, Libor Forst, 2010 - part 6 - case studies