Write a bash script to calculate the frequency of each word in a text file words.txt.

For simplicity sake, you may assume:

words.txt contains only lowercase characters and space ' ' characters. Each word must consist of lowercase characters only. Words are separated by one or more whitespace characters. Example:

Assume that words.txt has the following content:

the day is sunny the the
the sunny is is

Your script should output the following, sorted by descending frequency:

the 4
is 3
sunny 2
day 1

Note:

  • Don’t worry about handling ties, it is guaranteed that each word’s frequency count is unique.
  • Could you write it in one-line using Unix pipes?

Solution# 

echo "clean file"
rm words.txt

echo "make file to test"
cat << EOF > words.txt
the day is sunny the the
the sunny is is
EOF

echo "run solution"
cat words.txt | tr -s ' ' '\n' | sort | uniq -c | sort -n -r | awk '{ print $2, $1 }'