Creating indented text with bash

Question

Hello. I want to print a list to screen in a readable way. I use a loop to go through each element and make a new list which is formatted with commas and newlines. The problem is that in the first line of the output, I want a title. E.g., I want to print something like this:

List: red, green, blue, black, cars,
      busses, ...

The problem is to create the indentation in the second and following lines. I want the indentation to be of a given length. Therefore the problem is reduced to creating an empty line of a given length. That is, I want a function, create_empty_line_of_length, that outputs the given amount of spaces.

length=5
echo "start:$(create_empty_line_of_length $length) hello"

The output should in this case be:

start:      hello

Does anyone know how to do this?

Answer 1

It'll be

yes ' ' | head -7 | tr -d '\n'

Change '7' into your number.

Maybe you should take a look at

man fmt

also.

Answer 2

 printf '%7s'

Will probably the most efficient way to do it.

Its a shell builtin most of the time, and if not /usr/bin/printf exists as a fallback from coreutils.

so

 printf '%7s%s\n%7s%s\n' '_' 'hello' '_' 'world'

produces

      _hello
      _world

( I used _ instead of space here, but space works too because bash understands ' ' )

Answer 3

Not sure if this is going to help you http://unstableme.blogspot.com/2008/12/awk-formatting-fields-into-columns.html