List words in a file

cat some_filename | \ 					# Open the file
tr [:blank:] '\n' | \ 					# transform whitespace into new line
tr '[:upper:]' '[:lower:]' | \ 				# Shift to lower case
sed 's/^[[:punct:]]*\([a-z]*\)[[:punct:]]*$/\1/g' | \ 	# Remove punctuation before and after words
grep '^[a-z]*$' | \ 					# Remove words containing punctuation
sort | \ 						# Sort
uniq -c | \ 						# Count
sort -rn | \ 						# Sort the count
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