How to count how many different word do i have in a file, in a column

Question

I have a CSV file.

"AGNOLI Valerio","ITA","AST"

In this example, the 2nd column says "ITA". I expect there are about 100 or so different nationalities listed in this file. I want to know exactly how many different nationalities there are.

Answer 1

cut -d ',' -f 2 filename | sort -u | wc -l

Basically, I am specifying the , as the delimiter in the cut command and extracting the values in the second column using -f flag. Now, I sort them using sort and the -u flag makes the command to list only unique values. Finally, I have the wc -l command to get the count of unique countries in the second column.

Testing

cat filename
jill,us,123
jack,us,345
jill,en,234
mark,en,432
kate,us,354
kane,ru,435

Now, after issuing the command, I get the output as,

cut -d ',' -f 2 filename | sort -u | wc -l
3

Answer 2

You can use awk which will do it more efficiently and do the count for you instead of invoking different binaries and forking a lot of processes.

awk -F, '{a[$2]++} END{ for (i in a) print i, a[i]}' filename.csv