right align/pad numbers in bash

Question

What's the best way to pad numbers when printing output in bash, such that the numbers are right aligned down the screen. So this:

00364.txt with 28 words in 0m0.927s 00366.txt with 105 words in 0m2.422s 00367.txt with 168 words in 0m3.292s 00368.txt with 1515 words in 0m27.238 

Should be printed like this:

00364.txt with   28 words in 0m0.927s 00366.txt with  105 words in 0m2.422s 00367.txt with  168 words in 0m3.292s 00368.txt with 1515 words in 0m27.238 

I'm printing these out line by line from within a for loop. And I will know the upper bound on the number of words in a file (just not right now).

Answer 1

For bash, use the printf command with alignment flags.

For example:

printf '%7s' 'hello' 

Prints:

  hello 

(Imagine 2 spaces there)

Now, use your discretion for your problem.

Answer 2

Here's a little bit clearer example:

#!/bin/bash for i in 21 137 1517 do     printf "...%5d ...\n" "$i" done 

Produces:

...   21 ... ...  137 ... ... 1517 ...