How to count number of unique values of a field in a pipe-delimited text file?

Question

I have a pipe-delimited csv file (can be made a .txt file if needed). I want a list of all unique values in column 4. I'm using a Mac with Terminal. Thanks

Sample:

12345|1|2|Blue|54321
23456|1|2|Blue|23456
34567|1|2|Green|34567

I'd like a list that includes 'Blue','Green'

Answer 1

With macOS's built-in awk like this:

awk -F'|' '{print $4}' YourFile | sort | uniq

Output

Blue
Green

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Your question title implies you expect the answer to be 2, because there are two unique values, in that case, count the lines too:

awk -F'|' '{print $4}' file | sort | uniq | wc -l
2