CODEWITHSUNDEEP
bash
Me All
Me All

Reputation: 269

Using piped commands to get a specific output in Bash

I'm following a programming course and I'm trying to do a practice activity but I'm stuck. I have a file with the following list:

Monday       day
Tuesday      day
Easter       holiday
Monday       day
christmas    holiday
Tuesday      day
Friday       day
Thursday     day
thanksgiving holiday

What I'm trying to do is

  1. sorting this list,
  2. printing a new list containing only those names that are not repeated,
  3. counting the number of times each word appears in the list, and
  4. inserting a tab between the counter and the word.

This would be my desired output:

1    christmas    holiday
1    Easter       holiday
1    Friday       day
2    Monday       day
1    thanksgiving holiday
1    Thursday     day
2    Tuesday      day

I have tried using the following line of code:

cat my_file | sort | uniq -c | less

My problem is that words are not really sorted because words starting with capital letters would come before words starting with lowercase letters. Also, I don't know how to add the tab between the number and the word (in my output, there's only a space between them).

Could you help me?

Upvotes: 2

Views: 59

Answers (1)

clemens
clemens

Reputation: 17721

You may use -f to sort case-insensitive, and replacing spaces with tabs with sed(1). cat my be omitted from the pipe:

sort -f my_file | uniq -c | sed $'s/  */\t/g' | less

Note: The dollar sign in front of the sed parameter interprets \t as tab and not as \t.

If the first tab in each line is annoying, you can remove it with sed as well:

sort -f my_file | uniq -c | sed 's/^ *//' | sed $'s/  */\t/g' | less

This produces:

1   christmas   holiday
1   Easter  holiday
1   Friday  day
2   Monday  day
1   thanksgiving    holiday
1   Thursday    day
2   Tuesday day

Finally, if you want to keep spaces between the second an the third column, you should omit the g (replace all occurences of the search pattern) from the second sed invocation:

sort -f my_file | uniq -c | sed 's/ *//' | sed $'s/  */\t/' | less

Result:

1   christmas    holiday
1   Easter       holiday
1   Friday       day
2   Monday       day
1   thanksgiving holiday
1   Thursday     day
2   Tuesday      day

Upvotes: 2

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