CODEWITHSUNDEEP
bashmacosawksedterminal
AKGreene
AKGreene

Reputation: 5

Create final column containing row numbers in text file

I am new to using the Mac terminal. I need to add a tab delimited column to a text file with 3 existing columns. The columns look pretty much like this:

org1     1-20     1-40
org2     3-35     6-68
org3     16-38    40-16

etc.

I need them to look like this:

org1     1-20     1-40     1
org2     3-35     6-68     2
org3     16-38    40-16     3

etc.

My apologies if this question has been covered. Answers to similar questions are sometimes exceedingly esoteric and are not easily translatable to this specific situation.

Upvotes: 0

Views: 335

Answers (3)

Ruslan Osmanov
Ruslan Osmanov

Reputation: 21502

If you want to add the line numbers to the last column:

perl -i -npe 's/$/"\t$."/e' file

where

  • -i replaces the file in-pace (remove, if you want to print the result to the standard output);
  • -n causes Perl to apply the substitution to each line from the file, just like sed;
  • -p prints the result of expression;
  • -e accepts Perl expression;
  • s/.../.../e substitutes the first part to the second (delimited with slash), and the e flag causes Perl to evaluate the replacement as Perl expression;
  • $ is the end-of-line anchor;
  • $. variable keeps the number of the current line

In other words, the command replaces the end of the line ($) with a tab followed by the line number $..

Upvotes: 1

Benjamin W.
Benjamin W.

Reputation: 52211

You can paste the file next to the same file with line numbers prepended (nl), and all the other columns removed (cut -f 1):

$ paste infile <(nl infile | cut -f 1)
org1     1-20     1-40       1
org2     3-35     6-68       2
org3     16-38    40-16      3

The <(...) construct is called process substitution and basically allows you to treat the output of a command like a file.

Upvotes: 0

James Brown
James Brown

Reputation: 37414

In awk. print the record and the required tab and row count after it:

$ awk '{print $0 "\t" NR }' foo
org1     1-20     1-40  1
org2     3-35     6-68  2
org3     16-38    40-16 3

Upvotes: 4

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