parallel demo

examples.sh

#!/bin/bash

# pull out census data per city file and put it into its own file
for i in $(ls raw_city_data/);
do
    echo "parsing $i"
    grep -i "census:population" raw_city_data/$i > census_populations/$i
done

# do the exact same thing, but takes a third the time (and makes your computer very very warm)
ls raw_city_data/ | parallel "grep -i \"census:population\" raw_city_data/{} > census_populations/{}"