COMP 3000 Lab 6 2012

This lab is due on Friday, Nov. 9, at 11:55 PM.

Run the following three commands in bash. (Note the \ is just to note the command continues on the following line.)

x=0; while builtin test $x -lt 50000; do echo "P1 C1 $x"; echo "P1 C2 $x"; \
  echo "P1 C3 $x"; let x=$(($x + 1)); done >> race.txt &
y=0; while builtin test $y -lt 50000; do echo "P2 C1 $y"; echo "P2 C2 $y"; \
  echo "P2 C3 $y"; let y=$(($y + 1)); done >> race.txt &

The following questions are based on these three lines.

1. Describe the output of the above lines. In particular, how is the output of the two commands intermingled in the file race.txt?
2. How could you modify the lines so that output to the file race.txt continues until a file "done" is created in the current directory (instead of testing the values of x and y)?
3. How many processes do these two lines generate on your system?