How can I sort a file by word frequency?

Question

I have a file containing a list of words, e.g. list.txt contains:

carrot
apple
pen
ukulele
pen
cinnamon
carrot
carrot

How do I sort this file so that the words which appear the most in it go to the top, and duplicates are removed?

e.g. I'd like list.txt to contain this after sorting:

carrot
pen
apple
cinnamon
ukulele

Answer 1

Normaly, I would use

:%! sort | uniq -c | sort -nr

but this is a shell depended answer.

Using only Vim language or ex-commands in Vim is a little bit more difficult and it is very nicely described on wikia in Word frequency statistics for a file.

Inspired by that article it is possible to replicate the output of :%! sort | uniq -c | sort -nr with

:%s/^\+/1\t/g
:sort
:g/^\c\(.\+\)\n\1$/norm! ^yiwj@"^Akdd
:sort! n

The ^A represents Ctrl-A and is inserted as CTRL-V + CTRL-A (or if you use Ctrl-V for paste, press Ctrl-Q then Ctrl-A).