Running shell script in parallel

Question

I have a shell script which

1. shuffles a large text file (6 million rows and 6 columns)
2. sorts the file based the first column
3. outputs 1000 fi

Answer 1

There is a simple, portable program that does just this for you: PPSS. PPSS automatically schedules jobs for you, by checking how many cores are available and launching another job every time another one just finished.