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.
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.