For command-line junkies, a useful idiom to learn is
list-of-something | sort | uniq -c | sort -nr
which will give a frequency count of list-of-something sorted in
descending order.
e.g. to show the frequency count of the 4-starting-letters of words
cat /usr/share/dict/words |\
cut -c 1-4 |\
sort | uniq -c | sort -nr |\
head
which will show something like
2043 over
1334 unde
1323 inte
1078 anti
1000 supe
951 semi
731 unco
700 poly
648 para
618 peri
The classic story about this relates to Doug McIlroy and Donald Knuth More Shell, Less Egg