Think multi core!

Just another hacking tip.
I normally write little bash scripts that do repeating jobs for me and I wrote a little script (simplified):

for i in `seq 100`; do ./ogp.py $i ; done

Very simple you would say. But where is the problem with this? This only uses one CPU core at a time. I normally work on a 2 core machine but I will be buying a 8 core soon. So this script only uses one. So now my script looks like this:

for i in `seq 100`; do ./ogp.py $i & done

Can you spot the difference. Now I background the job (&) and the loop continues to run. I will not clog up the process ques as the program only runs

$time ./ogp.py 1

real    0m0.034s
user    0m0.025s
sys     0m0.008s

But it makes some difference. No backgrounding:

$ time ./gentest

real    0m2.206s
user    0m1.479s
sys     0m0.727s

And backgrounding

$ time ./gentest

real    0m1.128s
user    0m1.469s
sys     0m0.734s

So even with bash scripts you have to take the increase in core count serious.
Note: You don't need the line terminating ';' anymore as '&' acts as a line terminator too. So

for i in `seq 100`; do ./ogp.py $i &; done

Would be wrong