Next we'll look at the sort command. This is one of the most powerful commands on a Unix-style system; one that you will often find yourself using when setting up fancy data plumbing.
The sort command reads and sorts each file named on the command line. It then merges the sorted data and writes it to standard output. It will read standard input if no files are given on the command line (thus making it into a filter). The sort is based on the character collating sequence or based on user-supplied ordering criteria.