UNIX for Dummies Questions & Answers

Hi Guys,

I was going some trial and error to see if I can find the longest word in a text.

I was using Pipes because they are easier to use in this case.
I was stuck on this for a while so I thought I'll get some help with it.

I tried this code to separate all the words in a text in lines and this would give me the LENGTH of the longest word.

Code:

tr -s " .,;" "\n" <random.txt | tr '[A-Z]' '[a-z]' | sort -u | wc -L

But suppose if I want to display the longest word/s according to length (for example, longest word is 15 characters long and I want to display all words with the length of 15 characters).

I tried using this command but doesnt work

Code:

tr -s " .,;" "\n" <random.txt | tr '[A-Z]' '[a-z]' | sort -u | uniq -u

It's impossible to do with pipes - you need read all lines to find out the maximum length and then print saved lines which matches the maximum. Awk is a good tool for it - you read lines, save those with the current maximum and after processing you print all lines with the real maximum:

Code:

tr -s " .,;" "\n" <random.txt | awk 'length($0) >= max { a[$0]++; max = length($0) }
END {
  for (s in a) if (length(s) == max) print s
}'

Or a little better:

Code:

... awk '                                          
length($0)  > max { a[$0]++; max = length($0) }
length($0) == max { a[$0]++ }
END {                                       
  for (s in a) if (length(s) == max) print s
}'

it is possible to do it with pipes.
This will pretty much need 3 commands to complete

tr, wc and the command pipe should be able to do it. My lecturer was saying something about it

I will be happy to see. Bonus fortuna.

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